Preface

Nanocellulose derived from natural cellulosic materials has attracted significant interest due to its mechanical and optical properties, as well as its eco-friendliness, wide availability, recyclability, renewability, and low coefficient of thermal expansion (CTE). Various extraction techniques are employed to obtain nanocellulose, each with distinct advantages. Mechanical methods such as high-pressure homogenization and ultrasonication break down cellulose fibers effectively into nanoscale dimensions. Conversely, chemical approaches like acid hydrolysis and oxidation selectively remove amorphous portions, resulting in highly crystalline nanocellulose. Additionally, environmentally friendly extraction methods involve enzymatic processes that utilize cellulase enzymes to extract nanocellulose from cellulose-rich sources.

In an era marked by increasing environmental concerns and the quest for sustainable solutions, nanocellulose emerges as an inspiration of hope. This book, *Nanocellulose – Sources, Preparations, and Applications,* takes readers on a journey through the world of this remarkable material. Edited with meticulous care, this comprehensive volume stands as a testament to the collective efforts of researchers pushing the boundaries of material science.

The utilization of free-standing cellulose nanofiber (CNF) film extends to various applications, including serving as a potential barrier, packaging material, and membranes for wastewater treatment, as well as for fabricating biomedical films for wound repair, among other uses. The spraying process emerges as a notable method for large-scale production of films quickly and efficiently. The film's smooth and glossy surface offers opportunities for the development of functional materials, such as serving as a base substrate for flexible electronics and solar cells, leveraging its smoothness.

Nanocellulose has garnered significant attention due to its biocompatibility, renewability, robust mechanical strength, and cost-effectiveness, leading to exploration of its utilization across a wide array of applications. These applications include modifying nanocellulose for wettable applications, incorporating it as a carrier for antimicrobial agents, utilizing it as a barrier against UV rays or chemicals, and employing it for reinforcement in various fields such as biomedical, automotive, electronic, and energy materials. Despite promising potential, the utilization of nanocellulose remains an emerging field, encountering numerous technical challenges in achieving reliability, renewability, and sustainability for modern applications.

A promising source for ecofriendly biomaterial extraction is lignocellulosic natural fibers derived from trees, plants, agricultural waste, fruits, vegetables, seeds, and leaves. Various methods, including mechanical, chemical, and enzymatic procedures, are employed to extract nanocellulose from these natural sources. These techniques enable the production of nanocellulose with tailored morphologies, crystallinities, and surface functionalities, making them suitable for specific applications.

Advancements in nanocellulose preparation techniques involve the use of functional additives, surface modifications, and composite formations. These innovative approaches enhance the mechanical, thermal, and barrier properties of nanocellulose, thereby expanding its potential for use in cutting-edge applications.

The potential applications of the product span various research domains, including tissue engineering scaffolds and drug delivery systems within the biomedical sector, as well as the development of flexible and sustainable electronic devices in the realm of nanoelectronics. Nanocellulose serves as an advantageous component for enhancing the mechanical properties of composites due to its exceptional reinforcing capabilities in polymeric matrices. Its utilization extends to environmental applications such as water purification, oil spill clean-up, and the production of biodegradable packaging materials. Unlike cellulose sourced from plants and wood, bacterialderived nanocellulose boasts the greatest purity and natural nanofiber morphology, garnering increasing interest from researchers and industries alike. It possesses several unique attributes, including biomimetic nanoscale three-dimensional network structure, high water retention capacity, moldability into various shapes, inherent wet strength, excellent gas permeability, and favorable biocompatibility.

Pesticides play a vital role in safeguarding agricultural produce, protecting stored grain commodities and field crops from insect pests. Nanomaterials applied in plant protection offer numerous advantages over traditional pesticide products. Nanoenabled pesticides have the potential to alter the functionality or risk profile of active ingredients. Advanced nanotechnology has led to the development of new pesticide formulations that are less environmentally detrimental, cost-effective, and more efficient compared to conventional formulations. These innovations hold the promise of reducing environmental pollutants and fostering sustainable economic growth.

A paradigm shift towards sustainable practices is occurring, and the significance of nanocellulose cannot be overstated. From its renewable sourcing to its biodegradability, nanocellulose embodies the principles of green chemistry, offering a viable alternative to conventional materials.

This book serves as a repository of knowledge, exploring the diverse sources and preparations of nanocellulose. Chapter authors illuminate the intricacies of its production, from isolation techniques to functionalization methods. By providing a comprehensive overview, the book serves as a useful reference for researchers and practitioners, providing them with the tools necessary to harness the full potential of this sensation material.

Moreover, *Nanocellulose – Sources, Preparations, and Applications* transcends mere academic discourse, offering insights into real-world applications. From biomedical engineering to sustainable packaging, nanocellulose demonstrates its versatility across numerous fields. By showcasing innovative case studies and cutting-edge research, the book inspires readers to envision novel solutions to contemporary challenges.

As we navigate the complexities of the current century, the urgency of sustainable innovation has never been more apparent. In this context, nanocellulose emerges as a game-changer, poised to revolutionize industries and redefine our relationship with

the environment. Yet, realizing this vision necessitates collaboration, innovation, and a commitment to pushing the boundaries of scientific inquiry.

The book on nanocellulose represents a manifesto for a sustainable future. It encourages us to embrace the transformative potential of nanocellulose and embark on a journey towards a more sustainable and prosperous tomorrow.

Although this work was an addition to my routine academic workload, it was thoroughly enjoyable. I would like to thank my students for their patience in receiving delayed support from me. Lastly, I would like to thank my son Md Mehrab Newaz Kazi and my wife Nilufa Parveen for their sacrifices in our daily life throughout the duration of my editing work.

> **Salim Newaz Kazi** Department of Mechanical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur, Malaysia

Section 1
