The current application of nanotechnology in food and agriculture.

Over the past few years, nanocellulose (NC), cellulose in the form of nanostructures, has been proved to be one of the most prominent green materials of modern times. NC materials have gained growing interests owing to their attractive and excellent characteristics such as abundance, high aspect ratio, better mechanical properties, renewability, and biocompatibility. The abundant hydroxyl functional groups allow a wide range of functionalizations via chemical reactions, leading to developing various materials with tunable features. In this review, recent advances in the preparation, modification, and emerging application of nanocellulose, especially cellulose nanocrystals (CNCs), are described and discussed based on the analysis of the latest investigations (particularly for the reports of the past 3 years). We start with a concise background of cellulose, its structural organization as well as the nomenclature of cellulose nanomaterials for beginners in this field. Then, different experimental procedures for the production of nanocelluloses, their properties, and functionalization approaches were elaborated. Furthermore, a number of recent and emerging uses of nanocellulose in nanocomposites, Pickering emulsifiers, wood adhesives, wastewater treatment, as well as in new evolving biomedical applications are presented. Finally, the challenges and opportunities of NC-based emerging materials are discussed.

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Nanocellulose: From Fundamentals to Advanced Applications

Cellulose is the most abundant polysaccharide on Earth. It can be obtained from a vast number of sources, e.g. cell walls of wood and plants, some species of bacteria, and algae, as well as tunicates, which are the only known cellulose-containing animals. This inherent abundance naturally paves the way for discovering new applications for this versatile material. This review provides an extensive survey on cellulose and its derivatives, their structural and biochemical properties, with an overview of applications in tissue engineering, wound dressing, and drug delivery systems. Based on the available means of selecting the physical features, dimensions, and shapes, cellulose exists in the morphological forms of fiber, microfibril/nanofibril, and micro/nanocrystalline cellulose. These different cellulosic particle types arise due to the inherent diversity among the source of organic materials or due to the specific conditions of biosynthesis and processing that determine the consequent geometry and dimension of cellulosic particles. These different cellulosic particles, as building blocks, produce materials of different microstructures and properties, which are needed for numerous biomedical applications. Despite having great potential for applications in various fields, the extensive use of cellulose has been mainly limited to industrial use, with less early interest towards the biomedical field. Therefore, this review highlights recent developments in the preparation methods of cellulose and its derivatives that create novel properties benefiting appropriate biomedical applications.

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Cellulose and its derivatives: towards biomedical applications

Ullmann's Encyclopedia of industrial chemistry (Wiley)

Current advancement on the isolation, characterization and application of lignin.

Microcrystalline cellulose from Posidonia oceanica brown algae: Extraction and characterization

Aliphatic nitrate esters are currently the most widely used energetic ingredients in single-, double-, and triple-base propellants. These nitrate esters are unstable at ambient conditions, and stabilizing agents should be incorporated into the energetic compositions to inhibit and slow down the decomposition reactions that can occur. However, the currently used stabilizers present a number of environmental and human health issues. To overcome these shortcomings, many stabilizers have been appeared in the past few decades and continue to be developed. Furthermore, several analytical techniques have been introduced to monitor the stability of nitrate ester-based energetic materials as well, since the existing ones could not be efficiently applied. Therefore, this review paper discusses and summarizes the current and emergent stabilizers as well as their mechanisms of action. A critical and analytical examination of their advantages and drawbacks is made.

Stabilizers for nitrate ester-based energetic materials and their mechanism of action: a state-of-the-art review

This work reports the isolation of cellulose from giant reed through an ecofriendly multistep procedure including alkali treatment and totally chlorine free delignification, followed by acid hydrolysis to prepare microcrystalline cellulose using different acidic solutions (HCl, HNO3, H2SO4, HCl/HNO3 (2:1, v/v), and HCl/H2SO4 (2:1, v/v)). Several characterizations were performed in order to investigate the properties of each sample. FTIR results affirmed that the successive alkali treatment, totally chlorine free bleaching, and acid hydrolysis remove efficiently hemicellulose, lignin, and amorphous regions from the giant reed, and showed that the characteristic peaks of the prepared giant reed microcrystalline celluloses (GRMCC-HCl, GRMCC-HNO3, GRMCC-H2SO4, GRMCC-HCl/HNO3, and GRMCC-HCl/H2SO4) were similar to those of the commercial one. XRD measurements exhibited that microcrystalline cellulose produced from giant reed belong to cellulose I allomorph, with crystallinity index ranging from 73 to 80%. SEM micrographs revealed non-uniform micro sized rod-like shape morphology of GRMCC samples. The thermal analysis results displayed that the thermal decomposition of the obtained GRMCCs shifted to higher temperatures compared to the respective giant reed cellulose. This work opened a new pathway to prepare cellulose and microcrystalline cellulose from an abundant natural source using an ecofriendly process, and it could be expected to have applications in several areas.

Ahmed Fouzi Tarchoun

Papers

Nanocellulose: From Fundamentals to Advanced Applications

Microcrystalline cellulose from Posidonia oceanica brown algae: Extraction and characterization

Stabilizers for nitrate ester-based energetic materials and their mechanism of action: a state-of-the-art review

Ecofriendly isolation and characterization of microcrystalline cellulose from giant reed using various acidic media

A Promising Energetic Polymer from Posidonia oceanica Brown Algae: Synthesis, Characterization, and Kinetic Modeling