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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
BIOINSPIRED AND GREEN SYNTHESIS OF NANOSTRUCTURES This unique book details various ways to synthesize advanced nanostructures using green methods, explores the design and development of sustainable advanced nanostructures, and discusses the antimicrobial and antiviral applications. The future of the world depends on immediately investing our time and effort in advancing ideas on ways to restrict the use of hazardous chemicals, thereby arresting further environmental degradation. To achieve this goal, nanotechnology has been an indispensable arena that has extended its wings into every aspect of modernization. For example, green synthetic protocols are being extensively researched to inhibit the harmful effects of chemical residues and reduce chemical wastes. This involves the study of nanotechnology for artful engineering at the molecular level across multiple disciplines. In recent years, nanotechnology has ventured away from the confines of the laboratory and has been able to conquer new domains to help us live better lives. Bioinspired and Green Synthesis of Nanostructures focuses on the recent developments and novel applications of bioinspired and biomimetic nanostructures as functionally advanced biomolecules with huge prospects for research, development, and engineering industries. It provides detailed coverage of the chemistry of each major class of synthesis of bioinspired nanostructures and their multiple functionalities. In addition, it reviews the new research results currently being introduced and analyzes the various green synthetic approaches for developing nanostructures, their distinctive characteristics, and their applications. The book provides readers with an understanding of the recent data, as well as various strategies for designing and developing advanced nanostructures using a greener approach. Audience The core audience of this book include materials scientists, nanoscientists, nanotechnologists, chemical and biological engineers, biochemists and biotechnologists. Industry process engineers and scientists working in nanomaterial synthesis will find this book extremely valuable.
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Veröffentlichungsjahr: 2023
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Table of Contents
Cover
Series Page
Title Page
Copyright Page
Preface
1 Green Synthesis: Introduction, Mechanism, and Effective Parameters
1.1 Introduction
1.2 What Are Nanoparticles?
1.3 Types of Nanoparticles
1.4 Approaches
1.5 Conclusion
References
2 Greener Nanoscience: Proactive Approach to Advancing Nanotechnology Applications and Reducing Its Negative Consequences
2.1 Introduction
2.2 Why Do We Need Green Nanoscience Approaches?
2.3 Green Nanotechnology
2.4 Green Synthesis of Nanomaterials
2.5 Advantages of Green Nanoscience
2.6 Conclusion
References
3 Optimization of the Process Parameters to Develop Green-Synthesized Nanostructures with a Special Interest in Cancer Theranostics
3.1 Introduction
3.2 Mechanism Underlying Green Synthesis
3.3 Green Synthesized Nanoparticles in Cancer Theranostics
3.4 Optimizing the Synthesis and Subsequent Characterizations
Acknowledgment
References
4 Sustainability: An Emerging Design Criterion in Nanoparticles Synthesis and Applications
4.1 Introduction
4.2 Biotemplates
4.3 Synthesis Routes
4.4 Applications
4.5 Conclusion and Outlook
References
5 Green Conversion Methods to Prepare Nanoparticle
5.0 Introduction
5.1 Bacteria
5.2 Fungi
5.3 Yeast
5.4 Viruses
5.5 Algae
5.6 Plants
5.7 Conclusion and Perspectives
References
6 Bioinspired Green Synthesis of Nanomaterials From Algae
6.1 Introduction
6.2 Algal System-Mediated Nanomaterial Synthesis
6.3 Factors Affecting the Green Synthesis of Nanomaterials
6.4 Applications of the Green Synthesized Nanomaterials
6.5 Future Perspectives
6.6 Conclusion
References
7 Interactions of Nanoparticles with Plants: Accumulation and Effects
7.1 Introduction
7.2 Uptake and Translocation of Nanoparticles and Nanocarriers in Plants
7.3 Nanoparticle-Mediated Sensing and Biosensing in Plants
7.4 Tolerance Versus Toxicity of Nanoparticles in Plants
7.5 Nanoparticle-Mediated Delivery of Fertilizers, Pesticides, Other Agrochemicals in Plants
7.6 Nanoparticle-Mediated Non-Viral Gene Delivery in Plants
7.7 Conclusions
Acknowledgments
References
8 A Clean Nano-Era: Green Synthesis and Its Progressive Applications
8.1 Introduction
8.2 Green Synthetic Approaches
8.3 Nanoparticles Obtained Using Green Synthetic Approaches and Their Applications
8.4 Conclusion
References
9 A Decade of Biomimetic and Bioinspired Nanostructures: Innovation Upheaval and Implementation
9.1 Introduction
9.2 Bioinspired Nanostructures
9.3 Biomimetic Structures
9.4 Biomimetic Synthesis Processes and Products
9.5 Application of Bioinspired and Biomimetic Structure
9.6 Conclusion
9.7 Future Outlook
Acknowledgments
References
10 A Feasibility Study of the Bioinspired Green Manufacturing of Nanocomposite Materials
10.1 Introduction
10.2 Biopolymers
10.3 Different Types of Bioinspired Nanocomposites
10.4 Fabrication of Bionanocomposites
10.5 Application of Bionanocomposites
10.6 Conclusion
References
11 Bioinspiration as Tools for the Design of Innovative Materials and Systems Bioinspired Piezoelectric Materials: Design, Synthesis, and Biomedical Applications
11.1 Bioinspiration and Sophisticated Materials Design
11.2 Biomedical Applications
11.3 Conclusion and Future Perspectives
Acknowledgment
References
12 Protein Cages and their Potential Application in Therapeutics
12.1 Introduction
12.2 Different Methods of Cage Modifications and Cargo Loading
12.3 Applications of Protein Cages in Biotechnology and Therapeutics
12.4 Future Perspective
12.5 Conclusion
Acknowledgment
References
13 Green Nanostructures: Biomedical Applications and Toxicity Studies
13.1 Introduction
13.2 Moving Toward Green Nanostructures
13.3 Methods of Nanoparticle Synthesis
13.4 Plant-Mediated Synthesis of Green Nanostructures
13.5 Microbe-Based Synthesis
13.6 Toxicity of Nanostructures
13.7 Conclusion
References
14 Future Challenges for Designing Industry-Relevant Bioinspired Materials
14.1 Introduction
14.2 Bioinspired Materials
14.3 Applications of Bioinspired Materials and Their Industrial Relevance
14.4 Bioinspired Materials in Optics
14.5 Applications in Medicine
14.6 Future Challenges for Industrial Relevance
14.7 Optics-Specific Challenges
14.8 Energy-Specific Challenges
14.9 Medicine-Specific Challenges
14.10 Conclusion
References
15 Biomimetic and Bioinspired Nanostructures: Recent Developments and Applications
15.1 Introduction
15.2 Designing Bioinspired and Bioimitating Structures and Pathways
15.3 Nanobiomimicry—Confluence of Nanotechnology and Bioengineering
15.4 Biofunctionalization of Inorganic Nanoparticles
15.5 Multifarious Applications of Biomimicked/ Bioinspired Novel Nanomaterials
15.6 Emerging Trends and Future Developments in Bioinspired Nanotechnology
15.7 Conclusion
References
Index
End User License Agreement
List of Tables
Chapter 2
Table 2.1 Summary of plant materials used for green synthesis of various nanop...
Chapter 4
Table 4.1 Using plant extracts for the synthesis of biogenic NPs.
Table 4.2 Biogenic nanoparticles synthesized from bacteria.
Table 4.3 Biogenic nanoparticles synthesized from fungi.
Table 4.4 Biogenic nanoparticles synthesized from yeast.
Table 4.5 Biogenic nanoparticles synthesized from algae.
Chapter 6
Table 6.1 Green algae-mediated biosynthesis of various nanoparticles.
Table 6.2 Brown algae mediated biosynthesis of various nanoparticles.
Table 6.3 Red algae mediated biosynthesis of various nanoparticles.
Chapter 9
Table 9.1 Various bioinspired materials and their functions.
Table 9.2 Applications of bioinspired and biomimetic nanostructure.
Chapter 10
Table 10.1 Difference between conventional heating and microwave-assisted heat...
Chapter 14
Table 14.1 Bioinspired material properties along with corresponding sources an...
List of Illustrations
Chapter 2
Figure 2.1 Representation of some biological sources used in the green synthes...
Figure 2.2 Schematic representation of green nanomaterial synthesis.
Figure 2.3 Applications of green nanoscience.
Figure 2.4 Schematic representation of green nanomaterials-based biomedical ap...
Chapter 4
Figure 4.1 The green synthesis of nanoparticles is depicted in this schematic.
Figure 4.2 Plant or extract-based biosynthesis has several applications.
Figure 4.3 Microorganism-based biosynthesis has several applications.
Figure 4.4 Mechanisms involved during nanoparticle interaction with the plant....
Chapter 5
Figure 5.1 Schematic representation of the conventional synthesis technique of...
Figure 5.2 Schematic representation of the applications of various nanomateria...
Figure 5.3 Transmission electron micrographs showing the binding of gold to th...
Figure 5.4 UV-Vis spectrum of Fe
3
O
4
nanoparticles [with permission from Kannan...
Figure 5.5 (a) The absorbance spectrum of silver nanoparticles synthesized by ...
Figure 5.6 TEM images of (a) samples of nanoparticles after 72 hours incubatio...
Figure 5.7 TEM images of iron oxide nanoparticles synthesized using
Fusarium o
...
Figure 5.8 Absorbance spectra of (a) Ag/media and (b) Ag/mycelium solutions at...
Figure 5.9 Absorbance spectra of aqueous solution containing cell filtrate and...
Figure 5.10 Absorbance spectra of aqueous solution of 10
−3
M CdSO
4
solu...
Figure 5.11 Photos of Y. lipolytica cells incubated with 1 mM HAuCl4, (a) imag...
Figure 5.12 TEM images of iron phosphate nanoparticles biomineralized in a yea...
Figure 5.13 Transition electron microscope images of Tobacco mosaic virus with...
Figure 5.14 (a) Cowpea mosaic virus surface genetically modified with cysteine...
Figure 5.15 Transition electron microscope images of C. Vulgaris cells, where ...
Chapter 6
Figure 6.1 Applications of algae based nanomaterials in various fields.
Chapter 7
Figure 7.1 Summary of the various applications of nanoparticles covered in thi...
Figure 7.2 TEM images showing nanoparticles present in the xylem sap of (left ...
Figure 7.3 (a) Germination rate of rice seeds after priming with different pri...
Figure 7.4 (a) Measurement of pH inside the tomato stems using a pristine elec...
Figure 7.5 The phenotypic performance and chlorophyll content of salt stressed...
Figure 7.6 Maximum photosystem II quantum yields of B. juncea plants treated w...
Figure 7.7 Silencing of the magnesium chelatase H or I subunits (CHLH or CHLI)...
Chapter 9
Figure 9.1 Biomimetic synthesis of nanostructures.
Chapter 10
Figure 10.1 Sources of biomaterials.
Figure 10.2 Repeating unit of cellulose.
Figure 10.3 Chemical structure of chitosan.
Figure 10.4 Monomer, oligomer, and polymer of polylactic acid.
Figure 10.5 (a) Structure of HAp and (b) Chitisan-HAp nanocomposite.
Figure 10.6 Cellulose nanowhisker.
Figure 10.7 Protocol for nanowhisker preparation from cellulose.
Figure 10.8 Structure of nanoclay (2:1 type).
Figure 10.9 Various forms of nanoclay-polymer nanocomposites.
Figure 10.10 Cellulose-metal nanocomposite by ball milling method.
Chapter 11
Figure 11.1 Schematic of nature and nature-inspired materials based biopiezoel...
Figure 11.2 Diphenylalanine-based piezoelectric power generator. (a, b) Electr...
Figure 11.3 Wearable biopiezoelectric devices based on biomaterials. The outpu...
Chapter 12
Figure 12.1 Schematic showing possible ways of protein cage modifications and ...
Figure 12.2 Schematic showing therapeutic protein encapsulation and further de...
Chapter 13
Figure 13.1 Classification of nanoparticle synthesis [66].
Figure 13.2 Biomedical applications of nanomaterial produced by microorganisms...
Chapter 14
Figure 14.1 (A)(1) shows scales of
Cyphochilus
that are ~220 µm in length and ...
Figure 14.2 (A) Illustrates the schematic and experimental structure of hummin...
Figure 14.3 (A) Illustrates schematic diagrams of liposome (left) and polymers...
Figure 14.4 This figure displays different solutions for electrodes for neural...
Chapter 15
Figure 15.1 Commercially available nature-inspired products [4]. Reproduction ...
Figure 15.2 Bioinspired architectural construction of Manuel Gea Gonzalez (Hos...
Figure 15.3 Biomimetic design inspired from the double nanostructured pillars ...
Figure 15.4 Waterloo International Terminal—biomimicry of form and function.
Figure 15.5 Garden by the Bay, Singapore.
Figure 15.6 Schematic diagram demonstrating the release of anti-cancer medicin...
Figure 15.7 Bioinspired nanosensors for real time field data monitoring [104] ...
Figure 15.8 Biosensor operation [154]. Reproduction does not require any permi...
Figure 15.9 Nanosensor design schematic [123]. Reproduction does not require a...
Guide
Cover Page
Series Page
Title Page
Copyright Page
Preface
Table of Contents
Begin Reading
Index
WILEY END USER LICENSE AGREEMENT
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Scrivener Publishing100 Cummings Center, Suite 541JBeverly, MA 01915-6106
Publishers at ScrivenerMartin Scrivener ([email protected])Phillip Carmical ([email protected])
Bioinspired and Green Synthesis of Nanostructures
A Sustainable Approach
Edited by
Mousumi Sen
Department of Chemistry, Amity University, Noida, India
and
Monalisa Mukherjee
Amity Institute of Click Chemistry Research and Studies, Noida, India
This edition first published 2023 by John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA and Scrivener Publishing LLC, 100 Cummings Center, Suite 541J, Beverly, MA 01915, USA© 2023 Scrivener Publishing LLCFor more information about Scrivener publications please visit www.scrivenerpublishing.com.
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Library of Congress Cataloging-in-Publication Data
ISBN 978-1-394-17446-1
Cover image: Pixabay.ComCover design by Russell Richardson
Preface
This book focuses on the recent developments and novel applications of bioinspired and biomimetic nanostructures as functionally advanced biomolecules with huge prospects for research, development, and engineering industries. The population explosion, automation and urbanization have had numerous harsh environmental effects that have ultimately led to climate change. Therefore, the future of the world depends on immediately investing our time and effort into advancing ideas on ways to restrict the use of hazardous chemicals, thereby arresting further environmental degradation. To achieve this goal, nanotechnology has been an indispensable arena which has extended its wings into every aspect of modernization. For example, green synthetic protocols are being extensively researched to inhibit the harmful effects of chemical residues and reduce chemical wastes. This involves the study of nanotechnology for artful engineering at the molecular level across multiple disciplines. In recent years, nanotechnology has ventured away from the confines of the laboratory and has been able to conquer new domains to help us live better lives.
The green synthetic techniques produce nanostructures that generally possess unique properties that set them apart from those produced using physicochemical techniques. In addition to being eco-friendly, economic, and appropriate for mass production, these nanostructures possess diverse chemical, optical, mechanical, and magnetic properties as compared to bulk materials because of the increase in the surface area. An influential tenet of nanotechnology is the fabrication of nanoscale materials as well as their controlled morphology and dimensions. Learning from nature has given us different ways to address problems that arise when developing novel materials, which are known as biologically inspired and biomimetic strategies. These strategies, which rely on learning from surrounding entities, have experienced an unprecedented surge in the last decade, spurred on by advances in nanoscience and technology. Globally, the scientific community has recognized the prospects of an environmental catastrophe, and equitably providing clean air, food, water, and sustainable sources of energy is a matter of major concern. In the next 30 years, the desire for sustainable green alternatives is anticipated to double; therefore, the interdisciplinary holistic approaches pushing the idea of turning waste into profit require special emphasis.
In pursuit of a sustainable and eco-friendly abode, research focusing on the green synthesis of materials has revolutionized the design, development, and application of chemical products. Meticulous efforts for minimal waste products, synthesis of recyclable materials, and energy conservation have led to the research and discovery of ingenious strategies. Currently, green nanostructure synthesis is becoming extremely prevalent because it is safe and works well with living things. Green synthesis is merely a simplification of so-called logic that surpasses the fundamental concepts and techniques of synthesis. Therefore, the significance of green nanostructure synthesis must be examined in terms of how it is produced, its quality, and potential applications. The application of nanotechnology has enabled us to develop bioinspired materials using unique structures which can result in desired properties. With our increasing awareness of the scarcity of resources and surging pollution, there is a growing push towards the development of more bioinspired materials with better sustainability. As a result, they are growing in popularity, which makes studying them, their properties, and their fabrication techniques extremely important. Many bioinspired materials have already been developed that show great promise in solving many of our problems. But on the road to mass production, there are still some obstacles that are yet to be overcome. This book provides detailed coverage of the chemistry of each major class of synthesis of bioinspired nanostructures and their multiple functionalities. In addition, it reviews the new findings currently being introduced, and analyzes the various green synthetic approaches for developing nanostructures, their distinctive characteristics, and their applications.
Chapter 1 focuses on the synthesis and application of the nanostructures categorized as reliable, eco-friendly, and sustainable that have sparked a drive to develop environmentally acceptable methods. Hence, greener ways of identifying the biomolecules present in plants that mediate the formation of nanostructures, along with their production, testing and applications are also discussed.
Next, Chapter 2 discusses the limitations of existing nanotechnology-based methods to produce nanostructure and why we need the green nanoscience approach to overcome these limitations. The advantages of greener nanoscience have been described together with the processes for green nanostructure synthesis and the design and optimization of green processes to reduce or eliminate environmental and health hazards.
Chapter 3 gives the reader an insight into the mechanisms underlying different green nanofabrication techniques and the effect of various factors in the fabrication process. Statistical models and other in-silico approaches are frequently employed along with experimental data to ease the optimization. Although these techniques remain valid in optimizing the green synthesis of any nanomaterial, this chapter attempts to review the related reports and recent advancements in the field of cancer theranostics.
Chapter 4 evaluates the emerging nanomaterials possessing copious applications due to their nature and biological compatibility, high synthesis rate, stability, selectivity, sensitivity, and so on. Along the same lines, the practicality of biogenically developed nanostructure for biomedical applications, which has been recently ameliorated, is explored. This chapter also recounts sustainable approaches to effectively engineer nanostructures biogenically to be applied in demanding situations and applications.
A green synthesis strategy furnishes safe, clean and environment-friendly methodology to produce metallic nanoparticles. There is great demand for developing new protocols to enable the cost-effective and high-yield production of nanoparticle comparable to conventional methods. A significant step toward this would be improving eco-friendly processes for the creation of metallic nanoparticles. Thus, Chapter 5 is designed to explain the method of green synthesis, and the effects of various parameters on the size, morphology, and amount of metal nanoparticles produced.
The goal of Chapter 6 is to provide a brief overview of the variety of algal strains used in this booming field and the factors affecting them, along with the disparate nanocomposites synthesized.
The objective of Chapter 7 is to frame extensive guidelines and regulations based on the knowledge already available in the area of bioinspired “green” nanoparticles and implemented for the safe and efficient use of nanoparticles in farming, agriculture, and other botanical practices, aimed at the restoration of the delicate balance between living organisms and the environment.
Biogenic reduction of metal salts generally results in nanostructures possessing unique properties compared to those produced using physicochemical techniques. Thus, green synthetic techniques are eco-friendly, economic and appropriate for mass production. Chapter 8 provides a detailed review and analysis of the various green synthetic approaches for developing nanostructures, their distinctive characteristics and their applications. It also highlights the applications and improved properties of the nanostructures obtained using green synthesis.
Chapter 9 attempts to explain the advances in biomimetic and bioinspired nanostructures and present them as promising solutions to many unresolved problems in the biomedical field. Biomimetic nanostructures regulate the cell behavior reported in in-vitro studies, where they play an important role in cell nuclear alignment, cell spreading, cell differentiation, phagocytosis, and viability. Here, recent developments in the preparation of bioinspired and biomimetic nanostructures through different routes of synthesis are presented. The different templates used for the synthesis of nanostructures and binding the template with other useful materials to enhance the therapeutic efficacy are also discussed.
The recent trends in nano-functional materials and renewable materials for the preparation of bioinspired nanocomposites especially used in the agricultural, biomedical and healthcare sectors are discussed in Chapter 10.
Chapter 11 systematically discusses the recent development of bio-piezo-electric materials based on natural or nature-inspired biomolecules, with an emphasis on the design strategy, synthesis, integration into bio-piezoelectric platforms and finally their deployment in the latest biomedical applications.
Chapter 12 provides various ideas for designing nanoscale structures with targeted delivery ability which can be used in various applications, including therapeutics that may sound like science fiction.
Various green synthesis techniques and the contribution of green nanostructures in a variety of applications are highlighted in Chapter 13. The goal of this chapter is to provide a brief overview of the different green nanostructures used in this emerging field.
In Chapter 14, the industrial relevance of bioinspired materials is highlighted by focusing on the fields of optics, energy and medicine. Also discussed are the bioinspired materials that have found use in sensing, construction, adhesive manufacturing, communication, thermoregulation and many other fields.
Finally, Chapter 15 presents the broader concept of recent developments and novel applications of bioinspired and biomimetic nanomaterials. Biomimetics (biomimicry) is the development of novel biomaterials which not only mimic the composition of natural systems but also copy their structure, morphology and functionality. These bioinspired materials generally have their origins in nature and are designed by studying and imitating the remarkable biological processes of organisms and pathways of occurrence of different natural phenomena. The core technology of bio-inspiration is built upon deciphering how biological materials are constructed, and understanding the interactions that cause their unique properties.
In conclusion, we would like to express our gratitude to the many contributors for the hard work they put into this book. We would also like to thank all the authors for sharing their insightful research and information with us. We are very much thankful for Aarushi Sen for her unending encouragement and support throughout the making of this book. Her help was much appreciated. We are also most grateful for the efforts of Martin Scrivener of Scrivener Publishing, whose help made this book possible. We thank him for his patience and consistent support throughout the journey.
Mousumi Sen
Monalisa Mukherjee
April 2023
1Green Synthesis: Introduction, Mechanism, and Effective Parameters
Mousumi Sen
Department of Chemistry, Amity Institute of Applied Sciences, Amity University, Uttar Pradesh, India
Abstract
Nanoparticles are synthesized by different methods, such as physical methods, chemical methods, and biological methods. The need is the greener pathway and method for the synthesis of nanoparticles so that the process in nontoxic and do not harm the environment. In a number of industries, including medicine, pharmaceuticals, and agriculture, nanoparticles are used. Nanobiotechnology when combined with green technology benefits the industries, environment, and human health. Green chemistry plays a vital role in generating the plant extract-derived nanoparticles (especially gold and silver). Plant extracts contain the biomolecules that help in reducing metal ions and create the nanoparticles, and this can be achieved via a single-step synthesis process. In addition to plant species extracts, there are lots of diverse range of plant species that helped in the production of nanoparticles. Microbial synthesis or biological methods are applied for the synthesis in a greener fashion using different microorganisms, such as algae, bacteria, fungus, etc. Silver nanoparticles being antibacterial in nature are of great interest. They are used to treat cancer, tumors, and used in drug delivery process and many more countless applications.
Synthesis has been categorized as a reliable, eco-friendly, and sustainable way of synthesizing nanoparticles that contain substances, like metal oxides and others. Hence, greener way which are involved in the formation of the nanoparticles using plant extracts and types of nanoparticles with their production, testing and applications of these nanoparticles as well have been highlighted.
Keywords: Green synthesis, nanoparticles, sustainable, inorganic nanoparticles, organic nanoparticles, phytochemical screening
1.1 Introduction
In this fast-growing and technology-oriented world, advancements in almost every field are going on, and science is no exception. Research in every possible field is currently going to improve the present situation, methods, problems. Researchers are working hard in various fields. One of the filed in which there is much research going on in present times is nanoparticles. Nanotechnology is the branch of science that deals with dimensions of approximately 1 to 100 nm [1]. Due to their size, orientation, and chemical and physical characteristics, they are widely used. All the properties (chemical, physical, and biological) of individual atoms/ molecules and their related bulk vary in fundamental ways within this size range of particles. This plays a vital role in many technologies, such as nanoparticles in optics, electronics, and medicinal science industries [2]. They are of particular importance due to their high surface-to-volume ratio and extremely small size, which, when compared to the majority of the same chemical compositions, causes both chemical and physical alterations in their properties. Massive advancements in the technologies had ushered forth new eras. This comprises creating nanoscale materials and then studying or utilizing their intriguing physicochemical and optoelectronic features. The methods to produce nanoparticles using plants extracts are stable, bio-degradable, environmentally safe, and cost-effective [3, 4]. These particles tend to form enormous clusters that result in deposition, diminishing their effectiveness, although they are independent of shape and size and instead suggest the stability of particles. These can be formed from larger molecules or created from the ground up, for example, by nucleating and growing particles from low concentration levels in the liquid or gaseous phase. Functionalization via conjugation to bioactive compounds is another method of synthesis. Since the early days of nanoscience, the synthesis of high-yielding, low-cost nanomaterials have been a major issue. The ability to produce particles with diverse forms, monodispersed, chemical content, and size is critical for the use of nanoparticles in medicine.
1.2 What Are Nanoparticles?
The name “nanoparticles” derives from the Greek word “nanos,” which means dwarf or extremely small. Nanoparticles are also called “nanomaterials.” Particles between 1 and 100 nm in size are referred to as nanoparticles. When these particles are compared to atoms, they are larger than only one atom. Atom clusters are defined as particles smaller than 1 nm. As we know particles are small, and they cannot be detected by the human eye and microscopes. They are particles, smaller in size, so they can pass through candles or filters. The smaller the size of the particle, the larger will be the surface area. The main characteristic of nanoparticles is that they have a large surface area to volume ratio. Their sizes may vary as they are very small. They differ in their physical and chemical characteristics. The term nanoparticle can also be used for bigger particles and having a range up to 500 nm. They are differentiated from three particles: (i) microparticles—particles have ranged between 1 and 100 µm; (ii) Fine, particles have ranged between 100 and 2500 nm; (iii) Coarse- particles have ranged between 2500 and 10,000 nm.
They are environmentally friendly. These particles do not need any high temperature, energy, pressure, or any other kind of toxic chemicals [5]. The advantage of the nanoparticle is by reducing microorganisms and their cultures. These particles appear in nature and are mostly used in medicines, industries, laboratories, etc.
Richard Feynman, an 11-year-old American physicist and Nobel Prize winner, introduced the idea of nanotechnology for the first time in 1959. His goal was to use machines to create even smaller, molecular-level devices. He is also called as father of modern nanotechnology. The term “nanotechnology” was first used and defined by a Japanese scientist named Norio Taniguchi in 1974, which was 15 years later. Nanotechnology, according to him, is the separation, distortion, and consolidation of material by one atom or one molecule during processing. Following this, scientists began to find the field of nanotechnology to be very interesting, and research in this area began. For the potential synthesis of nanoparticles, two paths or approaches—top-down approach and bottom-up approach—have been established. Both have pros and cons in terms of price, quality, turnaround time, and speed. Nanotechnology and nanoparticles are not brand-new fields. Even today, there are indications that nanotechnology has existed and been used in the past [6, 7]. The Lycurgus Cup is an illustration of ancient nanotechnology. It is a cup constructed from dichroic glass. It is a 4-century Roman glass, which has a unique property of changing color. When light is shining on the outside, it appears olive green, and when light is shining on the inside, it turns ruby red. By utilizing transmission electron microscopy (TEM) to examine the cup in 1990, scientists were able to determine the cause of the colour change: the existence of nanoparticles with a diameter between 50 and 100 nm. After additional X-ray research, it was discovered that the nanoparticles detected in 21 of the cups were made of a silver-gold alloy with a silver to gold content of 7:3 and roughly 10% copper scattered throughout the glass matrix.
1.3 Types of Nanoparticles
Nanostructures (nanomaterials) are made up of organic polymers and inorganic polymers. so, these are classified into two types: (1) inorganic nanoparticles, (2) organic nanoparticles, both materials are of two dimensions or more than that. These are also of the same size as these nanoparticles are (1–100 nm) [8]. The organic nanomaterials are composed of liposomes, micelles, and polymer nanoparticles mostly used for drug delivery systems. A liposome is a lipid-based particle that includes a core that is surrounded by a thick layer called the phospholipid layer, whereas the inorganic nanoparticles are used for industrial, therapeutic purposes. These particles include Au, Ag, ZnO, CuO, and other metals and their oxides [9, 10].
1.3.1 Inorganic Nanoparticle
1.3.1.1 Green Synthesis of Silver (Ag) Nanoparticles
Silver (Ag) nanoparticles have a range between 1 and 100 nm in size. Due to the higher surface area of silver atoms, these particles are composed of silver oxide, as well as particles containing a solution of silver metal ions and a reducing agent. These have different physical, chemical, and biological properties. The ability to absorb water in Ag particles is high. The procedures of stabilization and reduction are used to create silver nanoparticles [11]. These are the simplest techniques. Stabilization can be achieved by the breakdown of a molecule, such as vitamins, proteins, etc. Extraction of silver particles is done by plants, such as Aloe vera, Saccharum officinarum, etc. (plants must be medicinal because Ag particles are very fundamental to biomedical applications). The most used shapes of Ag nanoparticles are diamond, spherical, etc. Ag plays a crucial role in electrochemical sensor platforms or biomedical applications [12].
The method for the synthesis of nanoparticle involves the following:
The target plant component is meticulously twice washed with tap water after being obtained from various locations in order to remove both epiphytes and necrotic plants. After that, any related material is removed using sterile distilled water [13]. Before being powdered in a home blender, the clean sources are dried for 10 to 15 days in the shade. Boil around 10 g of the dry powder in 100 mL of deionized distilled water to make the plant broth (hot percolation method). The infusion is then filtered until the soup contains no more insoluble particles. Pure Ag(I) ions are converted into Ag(0) when a small amount of plant extract is introduced to a 103-M AgNO3 solution [14]. This process may be observed by periodically analyzing the solution’s UV-visible spectra.
The preparation of Ag nanoparticles required a large portion of the flora. Different plants, as well as their various parts, are tested. Using the Alternanthera dentate aqueous extract, green fast production of spherical shaped Ag nanoparticles with diameters of 50–100 nm were observed [15, 16]. This extract’s conversion of silver ions to silver nanoparticles took only ten minutes. Extracellular Ag nanoparticles are synthesized using aqueous leaf extract, which is a fast, easy, and cost-effective method that are comparable to chemical and microbiological methods. Pseudomonas aeruginosa, Escherichia coli, Klebsiella 3 pneumoniae, and Enterococcus faecalis are all susceptible to silver nanoparticles. Acorus calamus was also utilized to make silver nanoparticles in order to test its antioxidant, antibacterial, and anticancer properties. A plant extract called boer-haavia diffusa was employed as the reducing agent in the green production of silver nanoparticles. According to XRD and TEM analysis, Ag nanoparticles with a face-centered cubic structure and spherical shape have an average particle size of 25 nm [17]. These nanoparticles were tested for their antibacterial potency against Pseudomonas fluorescens, Aeromonas hydrophila, and Flavobacterium branchiophilum, three fish bacterial infections. The most sensitive bacterium was F. branchiophilum, when compared to the other two. The reducing agents are present in relatively high concentrations in steroid, sapogenin, carbohydrates, and flavonoids, whereas phyto-constituents serve as capping agents and stabilise silver nanoparticles. The nanoparticles produced were determined to be spherical in shape, with an average size of the 7 to 17 nm. These nanoparticles have crystalline structure with a face cantered cubic (FCC) shape, as demonstrated by the XRD technique. Tea was employed as a capping agent to make crystalline silver nanoparticles with 20 diameters ranging from 20 to 90 nm. The amount of tea extract employed and the temperature of the reaction have an effect on the efficiency of production and also on the rate of nanoparticle formation. Ag nanoparticles with a spherical shape range in size from 5 to 20 nm, according to TEM. With callus extracted, the salt marsh plant Sesuvium portulacastrum L., Ag nanoparticles indicated a gradual shift in the colouration of the extracts to yellow-brown as the intensity of the extract rose over time [18]. A dried fruit body 41 Tribulus terrestris L. extract was combined to produce Ag nanoparticles with Ag nitrate This extract was utilized to create Ag nanoparticles with a spherical shape and a size range of 16 to 28 nm using the Kirby-Bauer process, which demonstrated antibacterial efficacy against multidrug-resistant bacteria, such as Streptococcus pyogens, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus. By combining ethyl acetate and methanol with tree extracts from 13 Cocousnucifera, a silver nanoparticle with a diameter of 22 nm was created. Salmonella paratyphi, Klebsiella pneumoniae, Bacillus subtilis, and Pseudomonas aeruginosa have all been found to exhibit antibiotic action. The Abutilon indicum extract was used to create a stable and spherical Ag nanoparticle. Those nanoparticles are having high antimicrobial action against the S. typhi, E. coli, S. aureus, and also, B. substilus bacteria. Silver nanoparticles are also made from Ziziphoratenuior leaves, and they were described utilizing a variety of methods. These nanoparticles were spherical in shape and uniformly distributed, according to the FTIR spectroscopic approach, with diameters ranging from 8 to 40 nm. Biomolecules with primary amine groups, carbonyl groups, hydroxyl groups, and other stabilizing functional groups were used to functionalize them [19]. In a recent work, these nanoparticles were also created using an aqueous mixture of Ficuscarica leaf extract and irradiation. Silver nanoparticles were created using aqueous solution of 5 mM silver nitrate after three hours of incubation at 37°C. P. aeruginosa, P. mirabilis, E. coli, Shigella flexaneri, Shigella somenei, and also Klebsiella pneumonia were all killed by the native fragrant plant Cymbopogan citratus (DC) stapf (commonly known as lemon grass) from India, which is widely cultivated in other tropical and subtropical nations. Krishnaraj et al. employed Acalypha indica leaf extract to make silver nanoparticles that developed in less than 30 minutes. When stable silver nanoparticles are generated at various AgNO3 concentrations, these particles are generally spherical with sizes ranging from 15 to 50 nm. TEM imaging revealed spherical particles with a size range of 3 to 12 nm that were well distributed. Dwivedi et al. showed how to make silver nanoparticles from the noxious plant Chenopodium album in a simple and quick way. Silver and gold nanoparticles with diameters ranging from 10 to 30 nm were effectively synthesized using the leaf extract. The spherical nanoparticles were discovered at increasing concentrations of the leaf extract, according to TEM imaging [20]. The growth kinetics of the Ag nanoparticles with the diameters of 10–35 nm were explored by Prathna et al., who made Ag nanoparticles by reducing silver nitrate solution with an aqueous extract of Azadirachta indica leaves. In a straightforward green approach, thermal treatment of the aq. silver nitrate solutions and the natural rubber latex obtained from Hevea brasiliensis resulted in colloidal silver nanoparticles.
1.3.1.2 Green Synthesis of Gold (Au) Nanoparticles
The size of gold (Au) particles can vary from 1 to 100 nm, and they have various visual and physical characteristics. The most crucial physical property is the Tyndall effect, i.e., scattering of light, perhaps the most crucial optical property is based on their structure, like size, shape, etc. and another optical property is Plasmon Resonance. Au consists of a core and protective coating, this protective coating shields the core of gold particle and hence prevent Gold Nanoparticle [21]. Au nanoparticles are toxic-free, environment-friendly, simple, and economical. The particle is used in various applications as a diagnostic tool, biosensors, drug delivery, etc. These are more favorable with peptides, proteins, and antibodies. The stability of Au particle is higher than Ag particle due to Au sulfur bond. The synthesis of Au nanoparticles can be done by three methods: biologically, physically, and chemically [22].
Chemically, through the reduction method of HAuCl4 with a solution of Thiolate Chitosan.
Physically, achieved via gamma–radiation technique.
Biologically, it can be achieved by reduction of HAuCl
4
.
Gold nanoparticles have gotten a lot of interest due to their one-of-a-kind potential for 28 usage in medicine and biology. They have a more biocompatible nature, tunable surface plasmon resonance, minimal toxicity, high scattering and absorption, easy surface functionalization, and simple synthesis processes, among other things [23]. When creating gold nanoparticles, reducing agents from biogenic complexes with a variety of chemical molecular composition are used. reacting with gold metal ions to produce reduction and nanoparticle formation. Various studies were also established that biomolecules contained in plant extracts, such as favonoids, phenols, protein, and others, play a great role in metal ion reduction and gold nanoparticle topping. Shankar and his colleagues were the first to use geranium leaf extract as a reducing and capping agent in the production of gold nanoparticles, which they did in 2003. The terpenoids in the leaf extract which are 39 responsible for the reduction of the gold ions to gold nanoparticles, which took 48 hours to complete [24]. According to morphological investigations, these nanoparticles are triangular, spherical, decahedral, and icosahedral in shape. They also used Azadirachta indica leaf extract to make gold nanoparticles in 2.5 hours. The neem extract’s terpenoids and favanones were probably absorbed on the nanoparticles’ surface and controlled their stability for four weeks. According to morphological studies, the nanoparticles are spherical and mainly planar, with the majority being triangular and some being hexagonal [25].
Aloe vera leaf extract was used by Chandran et al. to modify the size and form of gold nanoparticles. The amount of leaf extract used determines the size and form of the triangles, which range in size from 50 to 350 nm [26]. Less leaf extract was used to create larger nano-gold triangles in the HAuCl4 solution, but more leaf extract produced more spherical nanoparticles, which decreased the ratio of nano-triangle to nano-spherical particles. Using a modest extract quantity of 35 mushroom extract, some anisotropic gold nanoparticles were produced, with a maximum of triangles and prisms and a very small number of hexagons and spheres. When the amount of mushroom extract was increased, the nanoparticles’ shape changed to hexagons and spheres, reduced considerably, and the number of nanotriangles also shrank. The nanoparticles generated when the extracted quantity was increased to its greatest concentration were 25 nm in size [27]. Temperature had a great effect on the nanoparticles, which was clarified by receiving hexagons at 313 K at the greatest extract quantity, while nanoparticles in dendrites shapes were obtained at 353 Singh et al. observed temperature effects in the production of gold nanoparticles by Diopyros kaki and Magnolia kobus leaf extracts [28]. The nanoparticles were generated in the 10- to 35-nm range, according to morphological characterization using transmission electron microscopy [29].
1.3.1.3 Green Synthesis of Copper (Cu) Nanoparticles
Copper nanoparticles are made by reducing aqueous copper ions with various plant extracts, such as Aloe vera plant extract. A 578-nm signal on a UV–Visible spectrometer verified the making of Cu nanoparticles with an average size of 40 nm [30]. Cu/GO/MnO2 nanocomposite was synthesized using a leaf extract from Cuscuta refexa, which is high in antioxidant phytochemicals as Myricetin, Myricetin glucoside, Kaempferol3-Oglucoside (Astragalin), Kaempferol-3-O-galactoside, Kaempferol, Quercetin, Quercetin-3-O-glucoside, Quercetin 3-O. The ingredients listed above are responsible for converting plant extract into an antioxidant-rich feedstock for nanoparticle production [31−33]. Cu nanoparticles were fixed on surface of graphene oxide/MnO2 nanocomposites after Cu+2 ions were reduced to Cu nanoparticles using Cuscuta refexa leaf extract. For reduction of the rhodamine B, congo red, methylene blue, methyl orange, 4-nitro phenol, and 2,4-DNPH by NaBH4 in an aqueous solution, these nanocomposites with Cu nanoparticles were used as the heterogeneous and recoverable catalyst. Cheirmadurai and his colleagues used henna leaves extract as a reductant to make copper nanoparticles on a massive scale. Cu nanoparticles and collagen fibres left over from the leather industry were used to create nanobiocomposites conducting film. The film can be used in a wide variety of 15 17 electronic devices. Tamarind and lemon juice were also used to make large-scale Cu nanoparticles with sizes that are ranging from 20 to 50 nm. Using barberry fruit extract as a stabilizing and reducing agent, Cu nanoparticles were created in situ on reduced graphene oxide/Fe3O4 and were found to be useful as an active catalyst for the reaction of phenol with aryl halides to produce O-arylation of phenol under ligand-free circumstances. Additionally, it is recoverable and can be reused repeatedly without losing its catalytic properties [34].
1.3.1.4 Iron Oxide Nanoparticles
These nanoparticles contain iron oxide particles with sizes varying from one to one hundred nanometers. Magnetite (Fe3O4) and its oxidized counterpart maghemite (Fe2O3) are the two primary types [35]. They have piqued the interest of many people due to their superparamagnetic capabilities and prospective and are used in various industries. Due to their magnetic property, small size, and wide surface area, iron oxide nanoparticles are desirable for the elimination of heavy metal contamination from water, indicating their promise in metal-ion detection. It can be demonstrated that the produced iron oxide nanoparticles have a broad range of applications and are in high demand. Iron oxide nanoparticles exhibit a variety of magnetic behaviors and qualities, including high magnetic perceptivity and superparamagnetic activity. Magnetic iron oxide nanoparticles, such as magnetite and maghemite, are known for their biocompatibility and low toxicity [36]. This form of nanoparticle possesses potential to be a major source of concern for researchers working on bio-applications, data storage, and catalysis. The surface-to-volume ratio of these nanoparticles is extremely high, necessitating large surface energies. As a result, they can combine to minimize surface energy.
1.3.2 Organic Nanoparticles
Organic nanoparticles are two-dimensional materials ranges 1 to 100 nm in size. Nanoparticles have distinct size-dependent physical and chemical characteristics, such as optical, magnetic, catalytic, thermodynamic, and electrochemical capabilities. Liposomes, micelles, protein/peptide-based carriers, and dendrimers are the four basic types of organic Nano Particles [37]. Dendrimers are operating in multiple (15 nm) synthetic polymers having layered topologies with various terminal groups that regulate the dendrimer’s characteristics, a core structure, and an inner region.
1.3.2.1 Liposomes
Liposomes are circular vesicles consisting of one (or more) phospholipid bilayers. These mediums present themselves as an alluring delivery framework due to their physicochemical properties and biochemical nature permitting them to be effectively manipulated. Liposomes have an interesting capacity to encase lipophilic and hydrophilic compounds, making them appropriate carriers for a run of drugs. Other preferences, incorporate their capacity to self-assemble, capacity to carry expansive drug loads, and biocompatibility [38]. Being composed of characteristics phospholipids makes them “pharmacologically inactive”, meaning they show negligible harmfulness. Liposomes can be categorized into four fundamental types:
1. Conventional, 2. Theragnostic, 3. PEGylated, 4. Ligand-targeted
1.3.2.2 Micelles
A Micelle is a loosely bonded aggregation of 100 to 1000 atoms, ions, or macromolecules that constitute a colloidal particle—that is, one of several ultramicroscopic particles scattered through some continuous media. Micelles are significant in surface chemistry; for example, the ability of soap solutions to dissipate organic molecules that are insoluble or only weakly dissolve in water is described as a micelle.
1.3.2.3 Dendrimers
These macromolecules are highly branched, and globular [39]. These are used to encapsulate small individual drug molecules which can also be served as “hubs” which further results in huge numbers of drug particles and can be attached using covalent bonds. Example – 5-fluorouracil to poly amino amine dendrimers.
1.4 Approaches
Two types of Approaches help in producing Nanoparticles.
Top-down approach
Bottom-up Approach
Top-down Approach: This is the approach that starts with the bulk material and cuts the large material into smaller pieces to produce Nanoparticles. Examples: Ball Milling method. The Ball Milling method is a process that usually consists of Balls and a chamber called a mill chamber and stainless steel (balls must be of Iron, silicon Carbide, or Tungsten Carbide). they are made to rotate inside a Mill. this method helps in the production of nanoparticles. These mills are highly equipped with grinding media that contain tungsten carbide or steel. These mills rotate on the horizontal axis and are partially filled with the substance to be processed as well as the grinding medium [40]. The balls spin at high speeds inside a container before colliding with the solid and crushing it into nano crystallites due to gravity.
In a top-to-bottom technique, nanoparticle synthesis is typically accomplished by evaporation–condensation in the tube furnace at air pressure. The foundation material is vaporized into a carrier gas in this procedure, which takes place within a boat and is centred at the furnace. The evaporation/ condensation approach was previously used to make Ag, Au, PbS, and fullerene nanoparticles [41]. The tube furnace has a number of drawbacks, including taking up a lot of area and using a lot of energy to raise the temperature in the area around source material, as well as taking a long time to reach thermal stability. A typical tube furnace also requires several kilowatts of power and several tens of minutes of pre-heating time to reach a stable operating temperature [42]. One of the method’s 10 key shortcomings is that it causes defects in the product’s surface structure, plus further physical characteristics of nanoparticles are highly dependent on the surface structure in terms of surface chemistry. In general, chemical techniques, regardless of the method used, have some limitations, either with the help of chemical contamination during nanoparticle synthesis or in subsequent applications [43]. Their ever-increasing use in everyday life, however, cannot be underestimated. For example, “the noble silver nanoparticles” are pursuing cutting edge applications in every sphere of science and technology, including medicine, and hence cannot be dismissed solely as a result of their source of production. Ag 7 nanoparticles are used in over a total of 200 consumer goods, including apparel, medications, and cosmetics, due to their medical and antibacterial characteristics. Their expanding uses are bringing together chemists, physicists, material scientists, biologists, and doctors/pharmacologists to maintain their most recent foundations. As a result, it is now an obligation of every researcher to create a synthetic alternative that is not only economically effective but also environmentally beneficial Green synthesis is establishing itself as an important method and displaying its potential at the top in terms of aesthetics [44, 45]. Green production of nanoparticles has various compared to chemical and physical methods, including being environmentally friendly, cost-effective, and easily scaled up for large-scale nanoparticle creation. High temperatures, pressures, or energy, as well as hazardous substances, are not required.
A large number of literature has been published to date on biological production of microorganisms that use silver nanoparticles include fungi, bacteria, and plants due to their antioxidant or the reducing properties, which are typically responsible in the lowering of metallic compounds in their respective nanoparticles. Because the need for exceptionally aseptic conditions and their upkeep, microbe-mediated synthesis, one of numerous biological approaches for silver nanoparticle creation, is not industrially viable. As a result, plant extracts may be preferable to micro-organisms for this purpose due to their simplicity of improvement, lower biohazard, and more complicated cell culture maintenance method. It is the finest platform for nanoparticle syntheses since it is free of hazardous compounds and provides natural capping agents to stabilise silver nanoparticles. Furthermore, using plant extracts decreases the cost of culture media and microbe separation, making microbial nanoparticle manufacturing more cost-effective [46]. As a result, a report had been published that details bio-inspired silver nanoparticle syntheses that are more eco-friendly, cost-effective, and effective in the various types of applications, 16 particularly bactericidal activities, than physical and chemical methodologies.
The Technologies Based on the top-down approach are:
Evaporation/Condensation
The procedure is evaporation, in which liquid converts into vapors. The evaporation of the metal usually forms thin films, which are performed, under a high vacuum. this heat is produced by electrical resistance. This technique is based upon the pressure, which is created by vaporizing the metal, whose ability to evaporate is determined by its chemical strength. this is because of the evaporation via heating and then condensing the vapor to obtain nanoparticles. Steam generates through radiation and heating through the oxidation of Fe, Ni, Co, Cu, Pd, and Pt. The heating is required for oxygen and refractory metals. in the surroundings, if some metallic elements are reactive, then nanoparticles will oxidize [47]. the main disadvantage of this method is the lack of control over the nanomaterial size. The particles are synthesized by quickly condensing the escaped gas which is ensuring us the development of many Nanoparticles and other methods. this technique is most useful in the factory for manufacturing metal and ceramic nanoparticles. in the Air, nanoparticles are vulnerable to overheating and exploding.
Laser Ablation
This method makes use of a strong laser beam to generate nanoparticles. A high-energy laser focused on a target in a solvent in a top-down process. Pulses of light are being emitted by the laser and are sufficient to vaporize small patches of the metal target, which condenses as a nanoparticle in the solvent [48]. This procedure is typically used to create noble metallic nanoparticles such as gold, silver, and platinum. However, it may be easily extended to produce other nanomaterials such as metal alloy nanoparticles, which is a distinct advantage of this approach. A pulsed laser, a set of focusing optics, and a container carrying a metal target are typical components of a typical setup. The tank is filled with a solution (for example, water or ethanol), into which the metal object is placed. The metal object is placed near the laser’s focal point. The pulse duration, wavelength, and strength of the laser pulses can help to adjust the size and dispersion of the nanoparticles. Laser pulses are often measured in femtoseconds (1/1,000,000,000,000,000 of a second), picoseconds (1/1,000,000,000,000 of a second), or nanoseconds (1/1,000,000,000 of a second). Lasers of visible and near-infrared wavelengths are common in laser ablation equipment. Because the action is largely physical, this method can be utilized in multiple materials and solvents. Another distinct feature of this technology is the capacity to create nanoparticles with extremely high purity. Because there are no by-products or leftover compounds produced by this procedure.
Mechanical Milling
A mechanical milling method is a top-down approach to manufacturing nanomaterials, its simplicity, versatility of processes (suitable for manufacturing many types of nano-materials), expandability of processes., And are popular at low cost. There is. Most ultra-fine bulk materials are milled to the nano-range by strong mechanical shear forces in the milling process [49]. Three distinct types of grinding equipment are more frequently used than others. Shaker mill, planetary ball mill, allocation mill. As the name implies, in a shaker mill, the material to be ground is set up in a small bottle containing a “crushing ball”, which is a spherical ball of hard material. Then attach the sample firmly to the shaker and shake it vigorously back and forth for thousands of cycles per minute. During this shaking process, the crushed balls collide with one another and bounce off the walls of the vial. High shear and impact forces as a result crush and mix the solids. The planetary ball mill is named after the movement of the ampoules in the device. These vials are attached to a rotating disk that rotates about its axis, and each vial also rotates about its axis, but in the opposite direction of the main rotating disk. The entire system rotates at thousands of revolutions per minute, and strong friction and impact forces shred the material into smaller sizes [50]. Planetary ball mills are popular with many because they the ability to grind hundreds of materials at once. The attribution mill is similar to a ball mill, where the grinding balls are placed in a horizontal cylinder and rotated to complete the grinding process. However, in attraction mills, the vertical drum is secured internally via a string of carefully placed impellers. These impellers are fixed so that they are at right angles to each other. Unlike ball mills, attritor mills rotate at high speeds with the inner impeller running [51]. This can result in very high impact and shear forces that cannot be achieved with an attribution mill.
Advantages of Top-down Approach:
(i) manufacturing on a large scale (ii) Decontamination is not Required.
Disadvantages of Top-down Approach:
(i) Expensive Technique (ii) Broad Size Distribution (iii) Controlling over parameters is difficult to achieve (iv) do not have control over the Material dimensions.
Bottom-up Approach: This is the Approach that combines small atoms and molecules into larger structures. Example: - Colloidal Dispersion.
Colloidal Dispersion Method: This is the method in which the Dispersed phase is mixed with dispersion medium and then these are shaken well to Obtain the form of suspension. the suspension has to pass through a colloid mill. This Simplest type of colloid mill called disc mill barely consists of 2 metals discs that are nearly touching each other and are rotating in opposite directions and these rotations take place at high speed. This dispersion goes through these circular discs and is subjected to a tremendous shearing force, resulting in colloidal particles [52].
Advantages of Bottom-up Approach:
Cheaper Technique.
Narrow Size distribution is possible.
Ultrafine particles and nanotubes can be prepared.
More control over material dimensions.
Disadvantages of Bottom-Up Approach:
Large-Scale fabrication is difficult.
Decontamination is Required.
The Technologies based on the bottom-up approach are: The bottom-up strategy involves the development of both physical and chemical processes that function at the nanoscale to integrate major tiny components into larger structures. The strategy offers an acceptable completion to the top-down approach with a reduction in unit size. This method is motivated by biological systems, in which natural forces of life harness their chemical equivalents to form structures [53]. Scientists on the reverse side, are striving to create the same forces that nature uses to self-integrate into larger structures. When allowing undesirable deterioration, gold-palladium alloy nanoparticles based on carbon treated with acid and breaking down hydrogen peroxide are created from the conjunction of white hydrogen and red oxygen. This method has been utilized to create nanoparticles via condensation to the coalescence of atomic vapors.
Chemical techniques
a. Sol-Gel techniques
This method is based on Chemise douche chemistry, which provides quick and diverse ways for synthesizing extremely homogeneous, cost-effective nanomaterials with high purity into final oxidic structure networks. The size and morphological properties can be fine-tuned by varying the concentration ratio of capping agent to precursor and thus selecting a suitable reducing agent, as well as other reaction conditions, such as (1) generation of an appropriate precursor solution; (2) deposition of the solution onto a substrate, followed by hydrolysis and condensation; and (3) thermal treatment of their precursor and its conversion into the oxide nanoparticles. This enables the manufacturing of nanoparticles from alkoxides or colloidal solutions. They can be monoliths, crystallized nano pigments, or thin layers [54
