Preface

The circular bioeconomy involves the production and conversion of renewable biological resources and respective waste into value-added goods, such as bio-based products and bioenergy, in accordance with sustainable environmental and economic development. It is expected that lignocellulosic biomass will have a fundamental role in the evolution that is targeted for the circular bioeconomy worldwide. In this scenario, the importance of cellulose nanoparticles (CNPs) should be emphasized, given their wide range of applications that is already proven, in addition to others that will undoubtedly arise. Materials from lignocellulosic biomass, such as CNPs, can also collaborate in establishing both a sound interconnection and a beneficial transition, from the fossil-based economy of the last century to the bio-based one in progress.

Recently, cellulose nanoparticles, as a class of fascinating bio-based nanoscale materials, have received a tremendous amount of interest both in industry and academia owing to their unique structural features and impressive physicochemical properties such as biocompatibility, biodegradability, renewability, low density, adaptable surface chemistry, optical transparency, and improved mechanical properties. These nanomaterials are promising candidates for applications in fields such as biomedical, pharmaceuticals, electronics, barrier films, nanocomposites, membranes, and supercapacitors amongst others. New resources, new extraction procedures, and new treatments are currently under development to satisfy the increasing demands for cost-effective and sustainable methods of manufacturing new types of cellulose nanoparticle-based materials on an industrial scale.

The development of research into CNPs was instigated in the 21st century, mainly in the last decade. On the nanoscale, indexed publications were predominantly on cellulose nanocrystals (CNCs). The increase in the cellulose nanofibrils (CNFs) topic occurred mainly in the last 5 years, but still on a smaller scale, compared to CNCs.

The aim of this book, which is divided into two volumes (Cellulose Nanoparticles: Chemistry and Fundamentals and Cellulose Nanoparticles: Synthesis and Manufacturing), was to fill a gap in the current literature on research involving cellulose at the nanoscale, focusing more specifically on the topic of CNPs. In addition, a critical and analytical examination of the various approaches employed has been discussed.

The first three chapters of Cellulose Nanoparticles: Chemistry and Fundamentals cover the fundamentals and chemistry related to CNPs, followed by extraction processes and multiple techniques used to characterize them. Modifications of the surfaces of CNPs are important for several applications, such as to intensify interactions at the reinforcement–matrix interface in composites; these aspects are also included in this volume. Several chapters are devoted to the multiple types of materials that can be generated from CNPs, such as films, membranes, hydrogels, aerogels, and nanotubes. The first volume closes by addressing both the safety and environmental aspects related to CNPs.

The progress observed in the current century on the development of materials produced from a high content of renewables should be allied with the availability of advanced materials that could replace similar fossil-based ones. The second volume, Cellulose Nanoparticles: Synthesis and Manufacturing, meets these expectations, as many chapters are dedicated to different uses of CNPs in advanced materials.

In addition, it is expected that the renewable-grounded research will generate new materials from biomass, in response to a growing market contemporary demand. These features are essential to sustain and expand this segment over time, meeting the expectations of an increasingly demanding society in terms of economic and environmental sustainability. In this context, the chapters in Cellulose Nanoparticles: Synthesis and Manufacturing report research that includes the use of CNPs in diversified materials, such as rubbers, thermosets, gels, electrospun mats, films, 3D printed, paving the way for a wide range of environmentally sound applications. Specific approaches involving CNPs, such as on the water–energy–health–food nexus, energy storage, and optical sensors, properly complement the diversity of topics covered in Cellulose Nanoparticles: Synthesis and Manufacturing.

The plurality of approaches found in both volumes makes them attractive to academics, as well as engineers focused on innovations and applications that contribute to the development and consolidation of the circular bioeconomy.

Vijay Kumar Thakur

Elisabete Frollini

Janet L. Scott