Nanofillers: Fabrication, Characterization and Applications of Inorganic Nanofillers 9781032245898

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Nanofillers Analyzing the modifying effects of various inorganic nanofillers on the mechanical properties of polymer nanocomposites, this book covers processing, characterization, properties, and applications to analyze how these materials allow for innovative multifunction. This volume looks at various synthesis methods available within inorganic nanofillers and what characterizes them, covering design, manufacturing processes, and end-user results. The chapters focus on metal oxides, energy storage, and devices, alongside polymers used for packaging. This book details the role inorganic nanofillers have to play in cost-effective manufacturing processes due to their strength and efficiency, and their subsequent relevance to low-cost yet high-performance materials. Covering topics such as corrosion resistance, wear resistance, strength, and characterization, this book is an essential companion for any engineer working with inorganic nanofillers. This book will be of interest to engineers involved with inorganic nanofillers in a variety of industries, including automotive, aerospace, and biomedical engineering.

Nanofillers

Fabrication, Characterization and Applications of Inorganic Nanofillers

Edited by

Bhasha Sharma, Vijay Chaudhary, Shashank Shekhar, and Partha Pratim Das

First edition published 2024 by CRC Press 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742 and by CRC Press 4 Park Square, Milton Park, Abingdon, Oxon, OX14 4RN CRC Press is an imprint of Taylor & Francis Group, LLC © 2024 selection and editorial matter, Bhasha Sharma, Vijay Chaudhary, Shashank Shekhar and Partha Pratim Das; individual chapters, the contributors Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, access www.copyright. com or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. For works that are not available on CCC please contact mpkbookspermissions@tandf. co.uk Trademark notice: Product or corporate names may be trademarks or registered trademarks and are used only for identification and explanation without intent to infringe. ISBN: 9781032245898 (hbk) ISBN: 9781032245904 (pbk) ISBN: 9781003279389 (ebk) DOI: 10.1201/9781003279389 Typeset in Times by codeMantra

Contents Preface......................................................................................................................vii Editors........................................................................................................................ix Contributors...............................................................................................................xi Chapter 1 Outline and Classification of Inorganic Nanofillers in Polymers......... 1 M. G. R. Tamasha Jayawickrama, M. Iqbal Ishra, B. S. S. Nishadani, and M. M. M. G. P. G. Manthilaka Chapter 2 A Compendium of Metallic Inorganic Fillers’ Properties and Applications Employed in Polymers...................................................25 Qazi Adfar, Mohammad Aslam, and Shrikant S. Maktedar Chapter 3 An Exploration of Some Essential Inorganic Nanofillers................... 69 Dhananjay Singh, Deepak Singh, Suresh Kumar Patel, and G. L. Devnani Chapter 4 An Exploration of Some Essential Inorganic Nanofillers Apart from Metal Oxides, Metallic Particles, and Carbon-Based Nanofillers........................................................................................... 85 Bosely Anne Bose, B. C. Bhadrapriya, and Nandakumar Kalarikkal Chapter 5 To Comprehend the Applications of Inorganic NanofillerDerived Polymers in Packaging..........................................................99 Prakash Chander Thapliyal and Neeraj Kumar Chapter 6 Inorganic Nanofiller-Incorporated Polymeric Nanocomposites for Biomedical Applications.............................................................. 117 Mohammad Fahim Tazwar, Syed Talha Muhtasim, Tousif Reza, Yashdi Saif Autul, and Mohammed Enamul Hoque Chapter 7 Metal Matrix Nanocomposites (MMNCs) in Engineering Applications....................................................................................... 153 Abhishek Tevatia

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Chapter 8

Contents

Environmental Impact in Terms of Nanotoxicity and Limitations of Employing Inorganic Nanofillers in Polymers ......... 169 Feba Anna John, Ajith James Jose, and Litty Theresa Biju Chapter 9 Inorganic Nanofillers-Derived Polymers in Energy Storage Devices ................................................................................ 189 B. C. Bhadrapriya, Bosely Anne Bose, and Nandakumar Kalarikkal

Chapter 10 Fundamental Applications of Inorganic Nanofillers for Water Purification Using Polymers .............................................................203 P. A. Nizam and Sabu Thomas Chapter 11 The Integral Postulation of Inorganic Nanofiller-Derived Polymer Applications in Agriculture ............................................... 221 Puspendu Barik and Ashis Bhattacharjee Index .......................................................................................................................259

Preface Polymer nanocomposites have been investigated for about three decades. To get deep insights into the modifying effects of various nanofillers on the mechanical and physical properties of polymer nanocomposites, the four basic aspects of processing, characterization, properties, and applications will be critically discussed. Nanofillers do not represent only a creative alternative to design new materials and compounds for academic research, but their improved or unusual features allow the development of innovative multifunctional industrial applications. The development of these highperformance nanofillers requires thorough design, material selection, and synthesis. It involves the selection of fillers out of the vast number of fillers available today in the search for the required property. It also involves the determination of the best production process, considering the end-use requirements, and finally the fabrication of the material. This underscores the importance of the design and synthesis phases of polymer nanocomposite production. This book will provide researchers and industries to work on selecting the type of nanofiller (organic/inorganic) based on the targeted applications. The detailed discussion on synthesis, characterization, and application of nanofillers. The limitations and future perspectives of using nanofillers have been highlighted. The readers will get help understanding the selection criteria of nanofiller before utilizing them for various applications. This book will also address the advantages of inorganic nanofillers to promote applications of resultant nanocomposites. This book will also address the limitations of using nanofiller to promote sustainability and an eco-friendly environment, the economic aspects of using nanofillers, and their future perspectives. The contents of this book will be beneficial for students of mechanical engineering, civil engineering, material science, chemistry, physics, and researchers both working in industry and academia. In nutshell, this book will focus on the synthesis, characterization, and applications of inorganic nanofillers. We, the editors, would like to pay gratitude to contributors who have participated in the volume of this book. We are also thankful to the entire team at CRC Press (Taylor & Francis Group) for publishing this book in the fastest possible time and in the most efficient manner.

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Editors Dr. Bhasha Sharma is currently working as an Assistant Professor in the Department of Chemistry at Shivaji College, University of Delhi, India. She received her BSc in Polymer Sciences in 2011 from the University of Delhi. Dr. Sharma completed her Ph.D. in Chemistry in 2019 under the guidance of Prof. Purnima Jain from the University of Delhi. She has more than 7 years of teaching experience. She has published more than 40 research publications in reputed international journals. Her recently edited book titled Graphene-based biopolymer nanocomposites has been published in Springer Nature. Her authored book 3D Printing Technology for Sustainable Polymers and edited books Biodegradability of Conventional Plastics: Opportunities, Challenges, and Misconceptions and Sustainable Packaging: Gaps, Challenges, and Opportunities have been accepted by Wiley, Elsevier, and Taylor & Francis, respectively. Her research interests revolve around sustainable polymers for packaging applications, environmentally benign approaches for biodegradation of plastic wastes, fabrication of bionanocomposites, and finding strategies to ameliorate the electrochemical activity of biopolymers. Dr. Vijay Chaudhary is currently working as an Assistant Professor (Grade-I) in the Department of Mechanical Engineering, Amity School of Engineering and Technology (A.S.E.T.), Amity University Uttar Pradesh, Noida (India). He received his B. Tech. in 2011 from the Department of Mechanical Engineering, Uttar Pradesh Technical University, Lucknow, India and then completed M. Tech (Hons) in 2013 from the Department of Mechanical Engineering, Madan Mohan Malaviya Engineering College, Gorakhpur, India. He received his Ph.D. in 2019 from the Department of Mechanical Engineering, Netaji Subhas University of Technology, University of Delhi, India. His research areas of interest include processing and characterization of polymer composites, tribological analysis of biofiber-based polymer composites, water absorption of biofiber-based polymer composites, and surface modification techniques related to polymer composite materials. Dr. Chaudhary has over 8 years of teaching and research experience. He has published more than 40 research papers in peer-reviewed international journals as well as in reputed international and national conferences. He has published 16 book chapters with reputed publishers. More than 25 students have completed their Summer Internships, B.Tech. Projects and M.Tech. Dissertations under his guidance. Currently, he is working in the field of bio-composites, nanocomposites, and smart materials. ix

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Editors

Dr. Shashank Shekhar is currently an Assistant Professor at Netaji Subhas University of Technology and is also associated with the Quantum Research Centre of Excellence as Associate Director in the Department of Renewable Energy. He completed his PhD in Chemistry at the University of Delhi. Dr. Shekhar has been working on biopolymers and Schiff base metal complexes for the last 5 years and has published more than 20 articles in reputed international journals. He has 6 years of research and teaching experience. Presently, he is working on several projects, including the circular economy approach to plastic waste, synthesis of nanomaterials and nanocomposites for energy harnessing, biodegradation of plastic wastes, electrochemical analysis of resultant biodegradable nanocomposites for employment in supercapacitor applications, and polymer technology for packaging applications. Mr. Partha Pratim Das is pursuing Master of Technology (Materials Science and Metallurgical Engineering) in the Department of Materials Science and Metallurgical Engineering at Indian Institute of Technology Hyderabad (IITH), India. Currently, he is working in the field of active food packaging to extend the shelf-life of fresh produce with Cellulose and Composites Research Group at IIT Hyderabad. He completed his B.Tech in Mechanical Engineering with first-class distinction in the year 2021 from Amity University Uttar Pradesh, Noida, India. During his B.Tech, he worked on various projects with the Indian Institute of Technology Guwahati and Indian Oil Corporation Limited, Guwahati, Assam. He has presented several research papers at national and international conferences and published a good number of research papers in SCI journals and book chapters to his credit with reputed publishers including Springer, CRC press (T&F), and Elsevier. He also served as a reviewer in Materials Today: Proceedings and Applied Composite Materials, Springer. In the year 2020, he received the Innovative researcher of the year award. He is also a Certified Executive of Lean Management and Data Practitioner (Minitab and MS-Excel) from the Institute for Industrial Performance and Engagement (IIPE), Faridabad, India. He is a community associate member at American Chemical Society (ACS). His area of research includes natural fibre-based composites, processing and characterization of polymer matrix composites, nanofiller-based composites for various applications and biodegradable food packaging.

Contributors Qazi Adfar Vishwa Bharti Degree College Srinagar, India Mohammad Aslam Materials Chemistry & Engineering Research Laboratory, Department of Chemistry National Institute of Technology Srinagar, India Yashdi Saif Autul Department of Mechanical and Materials Engineering Worcester Polytechnic Institute (WPI) Worcester, Massachusetts Puspendu Barik Technical Research Centre S. N. Bose National Centre for Basic Sciences Salt Lake City, India B. C. Bhadrapriya School of Pure and Applied Physics Mahatma Gandhi University Kottayam, India Ashis Bhattacharjee Department of Physics Institute of Science Visva-Bharati University Santiniketan, India Litty Theresa Biju St. Berchmans College Changanassery Ernakulam, India Bosely Anne Bose School of Pure and Applied Physics Mahatma Gandhi University Kottayam, India

G. L. Devnani Department of Chemical Engineering Harcourt Butler Technical University Kanpur, India Mohammed Enamul Hoque Department of Biomedical Engineering Military Institute of Science and Technology (MIST) Dhaka, Bangladesh M. Iqbal Ishra Postgraduate Institute of Science University of Peradeniya Peradeniya, Sri Lanka and MRSC Institute of Materials Engineering and Technopreneurships Kandy, Sri Lanka M. G. R. Tamasha Jayawickrama Postgraduate Institute of Science University of Peradeniya Peradeniya, Sri Lanka and MRSC Institute of Materials Engineering and Technopreneurships Kandy, Sri Lanka Feba Anna John St. Berchmans College Changanassery Ernakulam, India Ajith James Jose St. Berchmans College Changanassery Ernakulam, India

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Contributors

Nandakumar Kalarikkal School of Nanoscience and Nanotechnology Mahatma Gandhi University Kottayam, India

Suresh Kumar Patel Department of Chemical Engineering Government Polytechnic, Lakhimpur Kheri Lakhimpur, India

Neeraj Kumar Centre for Nano Science and Engineering (CeNSE) Indian Institute of Science Bangalore, India

Tousif Reza Department of Mechanical Engineering Military Institute of Science and Technology (MIST) Dhaka, Bangladesh

Shrikant S. Maktedar Biofuels Research Laboratory Department of Chemistry National Institute of Technology Srinagar, India

Deepak Singh Department of Chemical Engineering Institute of Engineering & Technology Lucknow, India

M. M. M. G. P. G. Manthilaka Postgraduate Institute of Science University of Peradeniya Peradeniya, Sri Lanka and MRSC Institute of Materials Engineering and Technopreneurships Kandy, Sri Lanka Syed Talha Muhtasim Department of Mechanical Engineering Military Institute of Science and Technology (MIST) Dhaka, Bangladesh B. S. S. Nishadani Postgraduate Institute of Science University of Peradeniya Peradeniya, Sri Lanka and MRSC Institute of Materials Engineering and Technopreneurships Kandy, Sri Lanka P. A. Nizam School of Chemical Science Mahatma Gandhi University Kottayam, India

Dhananjay Singh Department of Chemical Engineering Government Polytechnic, Lakhimpur Kheri Lakhimpur, India Mohammad Fahim Tazwar Department of Mechanical Engineering Military Institute of Science and Technology (MIST) Dhaka, Bangladesh Abhishek Tevatia Department of Mechanical Engineering Netaji Subhas University of Technology New Delhi, India Prakash Chander Thapliyal Advanced Structural Composites and Durability Group CSIR-Central Building Research Institute Roorkee, India Sabu Thomas School of Energy Materials Mahatma Gandhi University Kottayam, India

1

Outline and Classification of Inorganic Nanofillers in Polymers M. G. R. Tamasha Jayawickrama, M. Iqbal Ishra, B. S. S. Nishadani, and M. M. M. G. P. G. Manthilaka University of Peradeniya Institute of Materials Engineering and Technopreneurships

CONTENTS 1.1 1.2

Introduction .......................................................................................................2 Classification of Nanofillers..............................................................................4 1.2.1 Zero-Dimensional Nanofillers ..............................................................4 1.2.2 One-Dimensional Nanofillers ...............................................................5 1.2.3 Two-Dimensional Nanofillers ...............................................................5 1.2.4 Three-Dimensional Nanofillers.............................................................5 1.3 Properties of Polymers, Inorganic Nanofillers, and Nanocomposites .............. 6 1.4 Applications of Inorganic Nanoparticles and Nanocomposites ........................ 7 1.5 Types of Inorganic Nanofillers ..........................................................................9 1.6 Synthesis of Nanofillers ....................................................................................9 1.7 Surface Modification of Nanofillers................................................................ 13 1.8 Preparation of Polymer-Inorganic Nanocomposites ....................................... 15 1.8.1 Sol–Gel Processing ............................................................................. 16 1.8.2 Blending .............................................................................................. 16 1.8.2.1 Solution Blending ................................................................ 16 1.8.2.2 Emulsion or Suspension Blending ....................................... 17 1.8.2.3 Melt Blending ...................................................................... 17 1.8.3 In Situ Polymerization ........................................................................ 17 1.9 Conclusion ...................................................................................................... 17 References ................................................................................................................ 18

DOI: 10.1201/9781003279389-1

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Nanofillers

1.1

INTRODUCTION

Twenty years ago, nanocomposite was not popular, and ‘hybrid’ or ‘molecular composite’ was used instead (Okada & Usuki, 2006). In those days, inorganic fillers were used as additives for polymers to enhance thermal, mechanical, and chemical stability. Those traditional fillers did not possess the superior properties of nanoparticles because most of the time they were in micron size. In 1990, the word ‘nanocomposite’ appeared for the first time on paper, which is a polymerclay hybrid in the polymer field for the first time. That polymer-clay nanocomposite was clay/nylon-6 nanocomposite, and it is to produce timing belt covers for a Toyota car. Based on their origin, fillers may be classified into two types: • organic fillers • inorganic fillers. (Kango et al., 2013) Caseri claimed (Caseri, 2000, 2009) that the first reported polymer-inorganic nanocomposite (PINC) in the literature was probably a polymer-Au nanocomposite by Lüdersdorff. A purple solid nanocomposite was obtained with the coprecipitation of gum arabic and gold in ethanol. And that resulting nanocomposite, known as the gold ruby glasses due to their red color, is still produced commercially. In particular, gold nanoparticles have been used as colorizing agents for glass for a long time (Caseri, 2009). Over the last two decades, scientific and technological interest has focused on polymer-inorganic nanocomposites (PINCs) due to their unique properties and numerous applications in modern technology (Hong & Chen, 2014; Li et al., 2010). The PINCs are mostly a simple combination of inorganic nanoparticles (nanometersized inorganic nanoparticles, typically in the range of 1–100 nm), which are uniformly dispersed in and fixed to a polymer matrix. It allows to combine/enhance the properties of the inorganic phase and the properties of polymers, and advanced new functions can also be generated for the PINCs (Ajayan et al., 2003; Li et al., 2010). As an example, the selectivity and thermal stability of the inorganic fillers and the flexibility and processability of polymers (Cong et al., 2007). Also, it leads to the new functionality of polymer-based materials or new processing methods for inorganic materials and it can provide high-performance novel materials that find applications in many industrial fields. Those nanoparticles are also termed ‘nanofillers’ or ‘nano-inclusions’ and in this kind of combination inorganic nanoparticles are acting like ‘additives’ to increase polymer performance (Ramanathan et al., 2007; Vaisman et al., 2007). Also, the nanoparticles have a strong tendency to disperse insufficiently in the polymer matrix and undergo agglomeration. This reduces the mechanical and optical properties of the nanocomposites (Kruenate et al., 2004; Yang et al., 2006). To improve the dispersion and reduce the agglomeration, surface modifications to the nanoparticles can be done to generate a strong repulsion between nanoparticles (Figures 1.1 and 1.12).

Outline and Classification of Inorganic Nanofillers in Polymers

3

FIGURE 1.1 Illustration of nanogap formation in the BPPOdp/silica nanocomposite membranes. (Adopted from Cong, Hu, et al., 2007.)

FIGURE 1.2 SEM photomicrographs of cross-sections of: (a) poly(1-trimethylsilyl-1propyne) (PTMSP) membrane and (b) PTMSP/silica nanocomposite membrane prepared by sol–gel process. (Adopted from Gomes et al., 2005.)

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1.2

CLASSIFICATION OF NANOFILLERS

Nanofillers are mainly classified according to their dimensions (Bhattacharya, 2016). These include (Figure 1.3): 1. 2. 3. 4.

Zero-dimensional nanofillers (nanoparticle) One-dimensional nanofillers (nanoplatelet) Two-dimensional nanofillers (nanofiber) Three-dimensional nanofillers (nanoparticulate)

1.2.1 Zero-Dimensional nanofillers Zero-dimensional nanomaterials have all the dimensions within the nanoscale (no dimension is larger than 100 nm). The nanoparticle is the most common example for zero-dimensional nanomaterial. These nanoparticles can be crystalline or amorphous, ceramic, metallic, or polymeric (Khan et al., 016).

FIGURE 1.3 Classification of nanofillers. (Adopted from Akpan et al., 2018.)

Outline and Classification of Inorganic Nanofillers in Polymers

1.2.2

5

one-Dimensional nanofillers

Nanofillers that have one of their dimensions less than 100 nm are called onedimensional (1D) nanofillers (Khan et al., 2016). They are typically in the form of sheets of one to a few nanometers thick to hundreds and thousands of nanometers long and are also found in the form of nanodisks, nanoprism, nanosheets, branched structures, nanoplates, and nanowalls (Dong et al., 2010; Jung et al., 2008; Mann & Skrabalak, 2011; Siril et al., 2009; Tiwari et al., 2012; Vizireanu et al., 2010). Those 1D nanofillers useful in the formation of nanodisks because they exhibit unique shape-dependent characteristics (Jung et al., 2008; Kim et al., 2009). And also, 1D nanofillers are useful in electrical and thermal applications such as biosensors, microelectronics, biomedical, sensors, and coatings because of their dimensionality and because of their excellent electrical, magnetic, and optic properties (Li et al., 2017). For example, nanographene platelets and montmorillonite clay layered silicates, MMT, graphite nanoplatelets (GNP), ZnO nanoplatelets, ZnO nanodisks, carbon nanowall, amphiphilic graphene platelets, ZnO nanosheets, and Fe3O4 nanodisks.

1.2.3 Two-Dimensional nanofillers Nanofillers that have two dimensions less than 100 nm are called two-dimensional (2D) nanofillers (Verdejo et al., 2011). They are mostly in the shape of fibers, tubes, or filaments. 2D nanofillers have better flame-retardant property compared with 3D and 1D nanofillers (Isitman et al., 2012), and they are very useful in sensors (Shahjamali et al., 2014), catalysis (Sanjeeva Rao et al., 2014), photocatalysts, energy, nanocontainers, nanoreactors (Pradhan et al., 2013), electronics, and optoelectronics. Compared with 3D fillers, 2D nanofillers found to provide a higher degree of reinforcement (Bhattacharya, 2016; Brune & Bicerano, n.d.). For example, Carbon nanotubes (CNTs), cellulose whiskers, boron nitride (BN) tubes, boron carbon nitride tubes, gold or silver nanotubes, 2D graphene, black phosphorus (Pradhan et al., 2013), and clay nanotubes.

1.2.4

Three-Dimensional nanofillers

Three-dimensional (3D) nanofillers relatively have particles in all three dimensions in the nanoscopic (nanometer) scale. They are generally referred to as nanoparticles or zero-dimensional or isodimensional nanoparticles and usually found in cubical and spherical shapes (Bhattacharya, 2016). Also, 3D nanofillers are commonly called as nanospheres, nanogranules, and nanocrystals. They are used in coatings (Olad & Nosrati, 2013), separation and purification (Maximous et al., 2009), and biomedicine (Matos et al., 2015) because they possess good stability, high refractive index, hydrophilicity, ultraviolet (UV) resistance and excellent transparency to visible light, nontoxicity, high photocatalytic activity, and low cost (Chen & Liu, 2011). For example, nanosilica, nanotitanium oxide, nanoalumina, semiconductor nanoclusters, carbon black, polyhedral oligomeric silsesquioxane (POSS), nanomagnesium hydroxide, silicon carbide, silica, and quantum dots (QDs) (Kumar et al., 2009).

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Nanofillers

1.3

PROPERTIES OF POLYMERS, INORGANIC NANOFILLERS, AND NANOCOMPOSITES

The addition of a certain amount of inorganic nanofillers to an organic polymer can increase the electrical conductivity, dielectric and mechanical properties, flame retardancy, thermal stability, chemical resistance, UV resistance, water repellency, environmental stability, radar absorption, magnetic field resistance, etc. (Sanchez et al., 2005). Those properties are strongly dependent on some characteristics of nanoparticles. • Size/aspect ratio (length/diameter) of the filler • Shape (e.g., spheres, rods, wires, polyhedrons, and core-shell structures) • Composition (e.g., metals, metal oxide, and semiconductors) (Burda et al., 2005; Daniel & Astruc, 2004). • Degree of dispersion of the filler and orientation in the matrix, and • The adhesion at the filler-matrix interface (Cho & Paul, n.d.) Inorganic nanoparticles (NPs) probably is one of the premier and broad applications in storage (Kramer & Sargent, 2014; Stratakis & Kymakis, 2013) catalysis (Masala & Seshadri, 2004), sensor (Cho et al., 2012), semiconductor, and medicine (Chan & Nie, 1998; Hu et al., 2012; Zhang et al., 2012). Because of the ability to enhance optical, mechanical, magnetic, and optoelectronic properties, those nanocomposites have been extensively used in various fields, such as safety, military equipment, automotive, protective garments, aerospace, optical devices, and electronics (Figure 1.4).

FIGURE 1.4 Illustration of uses of inorganic nanoparticles. (Adopted from Nie et al., 2016.)

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Outline and Classification of Inorganic Nanofillers in Polymers

TABLE 1.1 Synthesis, Properties of Selected Inorganic Nanoparticles Sr. No. Nanoparticle 1

TiO2

2

ZnO

3

Al2O3

4

SiO2

5

Magnetic

6

Ag

7

Au

Synthesis Hydrothermal, sonochemical, solvothermal, reverse micelles, sol–gel, flame spray pyrolysis, and nonhydrolytic approach Sol–gel, homogeneous precipitation, mechanical milling, organometallic synthesis, microwave method, spray pyrolysis, thermal evaporation, and mechanochemical synthesis Flame spray pyrolysis, reverse microemulsion, sol–gel, precipitation, and freeze-drying Sol–gel, flame synthesis, water-in-oil microemulsion processes Coprecipitation, microemulsions, sol–gel techniques, solvothermal, electrochemical, pulsed laser ablation, and sonochemical method Microwave processing, laser ablation, gamma irradiation, ultrasonic spray pyrolysis, photochemical method, chemical reduction by inorganic and organic reducing agents, thermal decomposition of silver oxalate in water and in ethylene glycol and electrochemical synthesis Chemical reduction, physical

Properties Optical, electronic, spectral, structural, mechanical and anti-corrosion properties Optical properties, thermal conductivity, electrical, sensing, transport, magnetic, and electronic properties Optical, transport, mechanical, and fracture properties Physicochemical, luminescent, optical, thermal, and mechanical properties Magnetic, caloric, physical, and hydrodynamic properties Optical properties due to surface plasmon resonance (SPR), antiangiogenic, thermal, structural, electrical, and catalytic properties Optical and photothermal properties

Source: Adopted From Kango et al. (2013).

When choosing a polymer, mechanical, thermal, electrical, optical, and magnetic behaviors, hydrophobic/hydrophilic balance, chemical stability, bio-compatibility, optoelectronic properties, and chemical functionalities (i.e., solvation, wettability, templating effect, etc.) are being considered. Fillers are not only used to reduce the cost of the composites. Generally, the reason for adding inorganic particles into polymers is to improve their mechanical properties such as the tensile strength, modulus, or stiffness via reinforcement mechanisms described by theories for nanocomposites (Fornes & Paul, 2003; Lee & Lin, 2006; Min et al., 2006; Pattanayak & Jana, 2005; Wang et al., 2005) (Table 1.1).

1.4 APPLICATIONS OF INORGANIC NANOPARTICLES AND NANOCOMPOSITES See Tables 1.2 and 1.3.

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Nanofillers

TABLE 1.2 Applications of Some Selected Inorganic Nanoparticles Sr. No. Nanoparticle 1

TiO2

2

ZnO

3

Al2O3

4 5

SiO2 Magnetic

6

Ag

7

Au

Applications Photocatalysis, dye-sensitized solar cells, gas sensor, nanomedicine, skincare products, wastewater treatment by removal of organic and inorganic pollutants, and antimicrobial applications Electronic and optoelectronic device applications, gas sensor, photocatalytic degradation of organic and inorganic pollutants for wastewater treatment, cosmetics, medical filling materials, antimicrobial, and anticancerous applications Wastewater and soil treatment by removal of heavy metal ions and antimicrobial applications, ceramic ultrafilters and membranes to remove pathogenic microorganisms, for gas separation, in catalysis and absorption processes, drug delivery, etc. Drug delivery, tissue engineering, carrier for antimicrobial applications, biosensing Biomedicine, cancer treatment, MRI, drug delivery, removal of toxic metal ions, and antimicrobial applications Antibacterial and antifungal applications in water purification systems, paints and household products, antiviral applications against HIV-I and monkeypox virus, biosensing Antibacterial and antiviral applications, biosensing, MRI, and cancer diagnosis

Source: Adopted From Kango et al. (2013).

TABLE 1.3 Potential Applications of Polymer-Based Inorganic Nanocomposites Nanocomposites Polycaprolactone/SiO2 Polyimide/SiO2 PMMA/SiO2 Poly(ethyl acrylate)/SiO2 Poly(p-phenylene vinylene)/SiO2 Poly(amide-imide)/TiO2 Poly(3,4-ethylenedioxythiphene)/V2O5 Polycarbonate/SiO2 Shape memory polymers/ SiC Nylon-6/LS Nylon-6/clay Nylon-6/clay

Applications Bone-bioerodible for skeletal tissue repair Microelectronics Dental application, optical devices, Bioactive bone substitute Catalysis support, stationary phase for chromatography Nonlinear optical material for optical waveguides Composite membranes for gas separation Cathode materials for rechargeable lithium batteries Abrasion resistant coating Medical devices for gripping or releasing therapeutics within blood vessels Automotive timing-belt-TOYOTA Barrier films – Bayer AG Films and bottles – Honeywell (Continued)

Outline and Classification of Inorganic Nanofillers in Polymers

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TABLE 1.3 (Continued) Potential Applications of Polymer-Based Inorganic Nanocomposites Nanocomposites

Applications

Nylon-6, 12, 66/clay Nylon-6/PP/clay UHMWPE/clay Polypropylene/clay PEO/LS

Auto fuel systems – ube Electrically conductive Earthquake-resistance pipes – Yantai Haili Ind. & Commerce of China Packaging – Clariant Airplane interiors, fuel tanks, brakes and tires, components in electrical and electronic parts PLA/LS Lithium battery development PET/clay Food packaging application. Specific examples include packaging for processed meats, cheese, confectionery, cereals and boil-in-the-bag foods, fruit juice and dairy products, beer, and carbonated drinks bottles Thermoplastic olefin/clay Beverage containers Polyimide/clay Automotive step assists (GM Safari and Astra Vans) Epoxy/MMT Materials for electronics SPEEK/laponite Direct methanol fuel cells EVA/clay Wires and cables (Kabelwerk Eupen of Belgium) Unsaturated polyester/clay Marine, transportation – Polymeric Supply Source: Adopted from Henrique Cury Camargo et al. (n.d.); Sanchez et al. (2005).

1.5

TYPES OF INORGANIC NANOFILLERS

There are many types of inorganic nanoparticles (Figures 1.5–1.8): • • • • • •

1.6

nanoclays silica metallic phosphates transition metal oxides nanometals metal chalcogenides

SYNTHESIS OF NANOFILLERS

Nanoparticles can be synthesized from many materials with particles differing in their elemental composition, shape, size, and chemical or physical properties using various physical and chemical methods (Masala & Seshadri, 2004). The physical methods depend on the principle of sub-dividing bulk precursor materials into smaller nanoparticles and generally involve vapor deposition. The chemical method is followed by the controlled aggregation of atoms and generally involves the reduction of metal ions into metal atoms in the presence of stabilizing agents (Chen & Liu, 2011). Chemical methods proved to be more effective than the use of physical methods for the synthesis of nanoparticles. The properties of nanoparticles of material completely different from their bulk counterparts. When the size decreases the

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Nanofillers

FIGURE 1.5 Types of inorganic nanofillers. (Adopted from Jeon & Baek, 2010.)

Outline and Classification of Inorganic Nanofillers in Polymers

11

FIGURE 1.6 SEM micrograph of silica nanoparticles prepared at optimal conditions. (Adopted from Luo et al., 2012.)

FIGURE 1.7 Some functional materials used in membranes for water purification. (Adopted from Paul & Robeson, 2008.)

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Nanofillers

FIGURE 1.8

Structure of sodium montmorillonite. (Adopted from Paul & Robeson, 2008.)

proportion of surface atoms increases and due to that the reactivity makes them highly reactive catalysts (Hanemann & Szabó, 2010) Due to their nanometer-scale size, they possess unique electronic, magnetic, optical, and mechanical properties. With these unique properties, nanoparticles can be used in applications in various fields, such as catalysis, drug delivery, wastewater treatment, magnetic resonance imaging (MRI), textiles, tissue engineering, paints, and cancer treatment (Tables 1.4 and 1.5). TABLE 1.4 Inorganic Nanoparticles Precipitated from Aqueous Solutions Metal

Starting Material

Co Ni Ni

Co(OAc)2 NiCl2 Ni(OAc)2

N2H4·H2O N2H4·H2O+NaOH N2H4·H2O+NaOH

none CTAB none

Cu Ag Ag Pt

CuSO4 AgNO3 AgNO3 H2PtCl6

Au

HAuCl4

N2H4·H2O Ascorbic acid NaBH4 potassium bitartrate trisodium citrate

SDS Daxad 19 TADDD TDPC S3MP

Reducing Agent

Stabilizer

Notes

Average Diameter (nm)

reaction performed at 60°C

~20 10–36

60°C simultaneous addition of reductant and stabilizer

(10–20) × (200– 300) rods ~35 15–26 3–5