Nanocellulose

The development of packaging materials with new functionalities and lower environmental impact is now an urgent requisite of our society. On one hand, the shelf-life extension of packaged products can be an answer to the exponential increase of worldwide demand for food. On the other hand, uncertainty of crude oil prices and reserves has imposed the necessity to find raw materials to replace oil-derived polymers. Additionally, consumers' awareness towards environmental issues increasingly pushes industries to look with renewed interest to "green" solutions. In response to these issues, numerous polymers have been exploited to develop biodegradable food packaging materials. Although the use of biopolymers has been limited due to their poor mechanical and barrier properties, these can be enhanced by adding reinforcing nano-sized components to form nanocomposites. Cellulose is probably the most used and well-known renewable and sustainable raw material. The mechanical pro...

1. The nutritional value of chocolate bars should be based on the nutritional value of the low energy dense late Paleolithic human diet to help reduce mental ill health, obesity, and other postprandial insults.
2. Current chocolate bars have a high energy density (>2 kcal/g).
3. Cocoa can be sweetened by the addition of calorie-free Purefruit™ (Tate & Lyle) monk fruit (Siraitia grosvenorii) extract. PUREFRUIT™ is approximately 200 times sweeter than sugar and has exceptional stability.
4. The energetic cost of the assimilation of chocolate can be increased by increasing its protein and fibre content.
5. Self-assembled, water-filled, edible nanotubes that self-organise into a more complex structure, possibly a 3D network of nanocellulose, could be incorporated into chocolate bars to lower their energy density to <1.6 kcal/g.
6. Durethan® KU 2-2601 packaging film enables the water content of chocolate bars to be increased without reducing product shelf life.
7. Aquatic biotechnology can provide all the nutrients needed to make chocolate really nutritious.

Over time, technological advancement has revolutionized the production and development of materials, and nanotechnology is a remarkable tool for this purpose. The research on the use and use of biomass has evolved in the last decades, within the forestry sector the study on nanocellulose has been highlighted, since this material, that can be produced by different routes, fibrillation or break by chemical or enzymatic hydrolysis, comes every time more showing potential of use. Because it is a renewable material, more advantageous to the environment when compared to materials of fossil origin, products containing nano-cellulose have a wide range of commercialization and opportunities, since the demands for biodegradable products, made from renewable and sustainable resources, and low environmental impact, are increasing.

The development of nanocellulose has attracted significant interest in the last few decades due to its unique and potentially useful features. Novel nanocelluloses boost the strongly expanding field of sustainable materials and nanocomposites. Their potential areas of application include reinforcing agents in nanocomposites, paper, biodegradable films, barriers for packaging, stabilizing agents in dispersions for technical films and membranes, additives in food, texturing agents in
cosmetics, and medical devices such as wound dressings and bioactive implants. This review organizes current knowledge on the isolation of microfibrillated and nanofibrillated cellulose from plant sources. Details of the extraction of fibrils from cellulose are reviewed. In addition, the terms cellulose “microfiber” and cellulose “nanofiber” are formally defined and distinguished.

The present doctoral thesis is based on experimental data obtained mostly using the structure of two research units: the “Laboratório de Reciclagem de Polímeros” at “Universidade Federal de Uberlândia”, Brazil, and “Laboratoire Génie des Procédés Papetiers” at “Université Grenoble Alpes”, France. This study was performed from 2014 to 2017 within the joint doctoral program between Universidade Federal de Uberlândia and Université Grenoble Alpes established in the agreement for cotutelle of doctoral thesis signed by these two institutions.
This manuscript is organized in three chapters. Chapter I is the literature review. This section was designed to provide most of information required to understanding of context of the research work developed in the following chapters. Through the analysis and comparison of selected publications, this chapter covers topics such as: cellulose
structure and its features, cellulose polymorphs, mercerization and regeneration process, cellulose nanocrystals, its production, properties and applications. Chapter II presents a comprehensive study of cellulose I and II nanocrystals prepared by sulfuric acid hydrolysis focusing basically on morphological and molecular structure. Chapter III is a
research work on mechanical properties of natural rubber nanocomposites reinforced using high aspect ratio cellulose nanocrystals isolated from soy hulls, with emphasis on the mechanical, thermal and morphological properties of the nanocomposites obtained. This manuscript is the original work of the author.

In nature, cellulose nanofibers form hierarchical
structures across multiple length scales to achieve highperformance
properties and different functionalities. Cellulose
nanofibers, which are separated from plants or synthesized
biologically, are being extensively investigated and processed
into different materials owing to their good properties. The
alignment of cellulose nanofibers is reported to significantly
influence the performance of cellulose nanofiber-based materials.
The alignment of cellulose nanofibers can bridge the
nanoscale and macroscale, bringing enhanced nanoscale
properties to high-performance macroscale materials. However,
compared with extensive reviews on the alignment of cellulose
nanocrystals, reviews focusing on cellulose nanofibers are
seldom reported, possibly because of the challenge of aligning cellulose nanofibers. In this review, the alignment of cellulose
nanofibers, including cellulose nanofibrils and bacterial cellulose, is extensively discussed from different aspects of the driving
force, evaluation, strategies, properties, and applications. Future perspectives on challenges and opportunities in cellulose
nanofiber alignment are also briefly highlighted.

This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The methodology of composite processing and resulting properties are fully covered, with an emphasis on neat and high fraction cellulose composites. Additionally, advances in predictive modeling from molecular dynamic simulations of crystalline cellulose to the continuum modeling of composites made with such particles are reviewed (392 references).

The present work deals with the preparation of
cotton linter nanowhiskers (CLNW) by acid hydrolysis and
subsequent processing in a high-pressure homogenizer.
Prepared CLNW were then used as a reinforcing material
in thermoplastic starch (TPS), with an aim to improve its
performance properties. Concentration of CLNW was
varied as 0, 1, 2, 3, 4 and 5 wt% in TPS. TPS/CLNW
nanocomposite films were prepared by solution-casting
process. The nanocomposite films were characterized by
tensile, differential scanning calorimetry, scanning electron
microscopy (SEM), water vapor permeability (WVP),
oxygen permeability (OP), X-ray diffraction and light
transmittance properties. 3 wt% CLNW-loaded TPS
nanocomposite films demonstrated 88 % improvement in
the tensile strength as compared to the pristine TPS polymer
film; whereas, WVP and OP decreased by 90 and
92 %, respectively, which is highly appreciable compared
to the quantity of CLNW added. DSC thermograms of
nanocomposite films did not show any significant effect on
melting temperature as compared to the pristine TPS. Light
transmittance (Tr) value of TPS decreased with increased
content of CLNW. Better interaction between CLNW and
TPS, caused due to the hydrophilic nature of both the
materials, and uniform distribution of CLNW in TPS were
the prime reason for the improvement in properties
observed at 3 wt% loading of CLNW in TPS. However,
CLNW was seen to have formed agglomerates at higher
concentration as determined from SEM analysis. These
nanocomposite films can have potential use in food and
pharmaceutical packaging applications.

The potential of pineapple peel as a source of cellulose nanocrystals was evaluated. Peels skin from fresh-cut fruit was used as raw material. These residues were purified to remove pigments, lipids and hemicellulose, and a bleaching process for delignification was carried out for 4-6 h. All resulting products were characterised for their lignin, hemicellulose, cellulose and ash contents using standard techniques. Dry matter at the end was low (ca. 50%) compared with the raw material (ca. 90%). The process applied resulted in ca. 20% (m/m) of purified cellulose (ca. 80% purity), with ineligible levels of lignin and hemicellulose present, especially when using 6h of bleaching. The purified cellulose was subject to acid hydrolysis for nanocrystal extraction with two testing times, 30 and 60 minutes. These cellulose nanocrystals had small sizes (< 1000 nm), with high variability and negative zeta potential values. The time of extraction did not affect the nanocrystals' chemical and physical properties. The use of 6 h of bleaching treatment during purification was shown to be more effective than 4 h. Pineapple peel was demonstrated to be a good source of cellulose for the production of cellulose nanocrystals.

Advanced templating techniques have enabled delicate control of both nano and microscale structures and have helped thrust functional materials into the forefront of society. Cellulose nanomaterials are derived from natural polymers and show promise as a templating source for advanced materials. Use of cellulose nanomaterials in templating combines nanoscale property control
with sustainability, an attribute often lacking in other templating techniques. Use of cellulose nanofibers for templating has shown great promise in recent years, but previous reviews on cellulose nanomaterial templating techniques have not provided extensive analysis of cellulose nanofiber templating. Cellulose nanofibers display several unique properties, including mechanical strength, porosity, high water retention, high surface functionality, and an entangled fibrous network, all of which can dictate distinctive aspects in the final templated materials. Many applications exploit the unique aspects of templating with cellulose nanofibers that help control the final properties of the material, including, but not limited to, applications in catalysis, batteries, supercapacitors, electrodes, building materials, biomaterials, and membranes. A detailed analysis on the use of cellulose nanofibers templating is provided, addressing specifically how careful selection of templating mechanisms and methodologies, combined toward goal applications, can be used to directly benefit chosen applications in advanced functional materials.

The isolation and characterization of nanocrystalline cellulose (NCC) from water hyacinth (WH) fibers were carried out. There are two treatments to obtain NCC from WH fibers by chemical and mechanical treatments. The chemical treatment involved alkalization with NaOH 25% in a highly-pressured tube, acid hydrolysis with 5M HCl, and bleaching with (NaClO 2 :CH 3 COOH) in ratio 5:2. The mechanical treatment was performed by using ultrasonic homogenizing at 12000 Rpm for 2 h. The morphological surface was observed by Transmission Electron Microscopy (TEM). TEM reported that the size of NCC was 10–40 nm. Crystallinity index and functional group analysis of the NCC WH fibers were also examined using X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. XRD reported that the crystallinity index increased significantly after chemical and mechanical treatment due to the presents of crystalline area in the WH fibers. The crystallinity index of raw fiber, digester, bleaching, and ultrasonic homogenizing were 7%, 68%, 69%, and 73% respectively. The content cellulose of final product was 68% as measured by the chemical composition test. Meanwhile, FTIR reported that WH fibers after being given chemical treatment lead the functional group change due to removal hemicellulose and lignin. The result of XRD and FTIR were indicated that the sample of NCC WH fibers presents the structure of cellulose crystal type I.

This work reported the thermomechanical and morphological properties of polyvinyl alcohol (PVA) nanocomposites reinforced with nanosilica and oil palm empty fruit bunches derived nanocellulose. The nanocomposites were characterized by mechanical, thermal, XRD, optical, and morphological studies. Uniformity dispersion of the nanofillers at a 3 wt% concentration has been shown by scanning electron microscopy, whereas the changes in crystallinity were demonstrated by X-ray diffraction analysis. Addition of nanosilica resulted in increased thermal stability of PVA/nanocellulose composites due to the reduction in mobility of the matrix molecules. Visible light transmission showed that the addition of 0.5 wt% nanosilica only slightly reduced the light transmission of PVA/nanocellulose composites with 3 wt% nanocellulose. The addition of a small concentration of nanosilica successfully improved the tensile and modulus properties of PVA/nanocellulose composite films. The increases in tensile strength and thermal stability were evidence of a nanosilica contribution in PVA/nanocellulose composites, inducing reinforcement, as detected by the thermomechanical properties.

Link to full text journal :
http://ojs.cnr.ncsu.edu/index.php/BioRes/article/download/BioRes_10_2_3364_Ching_Polyvinyl_Alcohol_Composite/3499

Diet, lifestyle and environment do not just affect a person's health, they also determine the health of their children and possibly the health of their grandchildren. Mental ill health is an epidemic worldwide because of the combined effect of the modern diet and a sedentary lifestyle. Primary prevention of mental ill health starts, crucially, with optimal adult nutrition before the inception of pregnancy, includes breastfeeding, and continues throughout the life of the newborn. Obesity in pregnancy and poor human nutrition must be tackled head on. Nanocellulose and calorie-free monk fruit extract could be used to lower the energy density of processed foods/drinks (< 1.6 kcal g−1), and their bioavailable brain nutrient content including cofactors can be increased using bioactive encapsulation. Aquatic biotechnology can provide all the nutrients needed to make processed foods really nutritious. The nutritional value of processed and farmed foods should be based on the nutritional value of the late Palaeolithic human diet to help prevent mental ill health and other postprandial insults. After all, disease prevention, in the long run, is far less costly than treatment.

reinforced epoxy resin and mean Young’s modulus from 404.82 Nm-2 for the unreinforced epoxy to 1088.7 Nm-2 and 1906 Nm-2 for the treated and untreated King palm fibre reinforced epoxy composites respectively. The mean ultimate stress, mean stress at break and mean yield point at break were also higher with increased weight fraction of the reinforcement from 0.028 to 0.112 in both cases of treated and untreated King palm fibre reinforced epoxy composites. However, the mean elongation at break, reduced from 4.233 mm for the unreinforced epoxy to 1.5173 mm and 3.3267 mm respectively for the treated and untreated King palm fibre reinforced epoxy composites. All the composites exhibited a pre-tensioning period, while increase in the weight fraction of the King palm fibre increased brittleness of the epoxy composites.

The second virial coefficient, B 2 is computed of linear rigid rods composed of m equally spaced sites interacting with sites on other rods via the hard-sphere or Weeks-Chandler-Andersen (WCA) pair potentials. The dependence of B 2 on a wide range of separation distance between the sites L and m for both types of potential is computed. Molecular dynamics simulations were carried out of the thermodynamic, static, and percolation properties of the WCA rigid rods in the isotropic phase as a function of rod number density ρ. Simple scaling relationships are discovered between thermodynamic and other static properties as a function of ρ and m, which extend well into the semidilute density range. The percolation threshold distance (PTD) between the centers of mass of the rods complies well with a mean-field random orientation approximation from low density well into the semidilute regime. The corresponding site-site PTD proved more problematic to represent by simple functions, but at high rod density, scales better with the number of sites density rather than the rod number density.

Cellulose nanocrystals (CNCs) from kenaf core were prepared using acid hydrolysis method while graphene oxide (GO) were synthesized from modified Hummer's method. Low filler content composites films of CNC (0.1-0.4 wt.%) and GO (0.1-0.6 wt.%) in PLA films were prepared separately using solution casting method. From tensile test, it was found that optimum modulus increment were obtained for 0.2 wt.% CNCs and 0.4 wt.% GO in PLA which gave an increment of 125 % and 40 %, respectively. Only a small amount of CNCs are needed to improve the tensile properties of PLA. From microscopic observation of fractured surface at higher filler contents, CNC agglomerates tend to form which serves as void nucleating agent during plastic deformation due to poor interfacial properties while GO agglomerates cannot be observed in composites. Improved mechanical properties were not due to increment of crystallinity in PLA but reinforcement from fillers.

The objective of this work was to find out the compositional characteristics of wheat straw in terms of cellulose and lignin contents and assess the suitability of wheat straw for isolation of cellulose microfibrils. The fractionation process includes formic acid/peroxyformic acid treatment, bleaching and ball milling of bleached cellulose. 39.10 % Cellulose, 20.40 % lignin and 25.02 % of other compounds were extracted. Extracted cellulose was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), and thermogravimetric analysis (TGA). Morphological and thermal analyses studies showed that the extracted microfibrils had reduced length and diameter and showed good thermal stability suitable for various advanced nano technological applications.

Objective of this work was to compare morphology,
crystalline and thermal properties of cellulose nano fibers
derived from wheat straw by two different processes (ball
milling and acid hydrolysis treatment). The characterization of
extracted CNFs was done by Scanning electron micrograph
(SEM), Transmission electron microscopy (TEM), X-ray
diffraction (XRD) and Thermogravimetric analysis (TGA). It
was found from morphological, crystalline and thermal
analyses that isolated cellulose nanofibers have diameter of
nano meter ranges (10-25 nm), 68-80 % crystallinity and
decomposition temperature of around 284-353o C, depending
upon isolation techniques.

Diet, lifestyle and environment do not just affect a person's health, they also determine the health of their children and possibly the health of their grandchildren. Non-communicable disease is a global epidemic because of the combined effect of the modern diet (including drug abuse) and a sedentary lifestyle. A low energy dense, drug-free diet rich in bioavailable nutrients-plus-exercise is most effective for preventing non-communicable disease throughout life. Nanocellulose and calorie-free monk fruit extract could be used to lower the energy density of processed foods/drinks (<1.6 kcal g−1), and their bioavailable nutrient content including cofactors can be increased using bioactive encapsulation. Drug abuse must be made socially unacceptable. Aquatic biotechnology can provide all the nutrients needed to make processed foods really nutritious. The nutritional value of processed and farmed foods should be based on the nutritional value of the late Palaeolithic human diet to help prevent cardiovascular disease, mental ill health, cancer, obesity, and other postprandial insults.

The wide availability and diversity of dangerous microbes poses a considerable problem for health professionals and in the development of new healthcare products. Numerous studies have been conducted to develop membrane filters that have antibacterial properties to solve this problem. Without proper protective filter equipment, healthcare providers, essential workers, and the general public are exposed to the risk of infection. A combination of nanotechnology and biosorption is expected to offer a new and greener approach to improve the usefulness of polysaccharides as an advanced membrane filtration material. Nanocellulose is among the emerging materials of this century and several studies have proven its use in filtering microbes. Its high specific surface area enables the adsorption of various microbial species, and its innate porosity can separate various molecules and retain microbial objects. Besides this, the presence of an abundant OH groups in nanocellulose grants its uniqu...

In this study, cellulose nanocrystals (CNC) were produced using acid hydrolysis method. Kenaf core was pretreated with 4 wt. % sodium hydroxide (NaOH), followed by bleaching using 1.7 wt. % sodium chlorite (NaClO 2) in acetate buffer. The bleached fiber was acid hydrolyzed for 45 and 55 min using 64 wt. % sulfuric acid (H 2 SO 4). The size distribution of the CNC segregated via differential centrifugation with different speed was also investigated. The CNC suspension obtained was centrifuged at 3000, 6000, 9000 and 12000 rpm. The resultant CNC suspension collected was characterized using Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM). FTIR results showed the progressive removal of non-cellulosic constituents for each subsequent treatment. It also showed that the CNC produced after hydrolysing for 55 min has the highest degree of crystallinity (81.15%). CNC produced from acid hydrolysis process of 45 min have lengths between 50 and 270 nm while CNC produced from acid hydrolysis process of 55 min have length around 40 to 370 nm. ABSTRAK Dalam kajian ini, selulosa nanohablur (CNC) dihasilkan menggunakan kaedah hidrolisis asid. Teras kenaf yang digunakan sebagai bahan mentah diprarawat menggunakan 4 bt. % natrium hidroksida (NaOH). Serabut yang telah dirawat kemudian dilunturkan menggunakan natrium klorit (NaClO 2). Hidrolisis asid telah dijalankan selama 45 dan 55 minit ke atas serabut yang telah dilunturkan menggunakan 64 bt. % asid sulfurik (H 2 SO 4). Taburan saiz CNC yang dihasilkan dikaji menggunakan teknik pengemparan dengan kelajuan yang berbeza. Ampaian CNC yang terhasil diemparkan pada kelajuan 3000, 6000, 9000 dan 12000 rpm. Ampaian CNC yang terhasil dianalisis menggunakan spektroskopi Fourier inframerah (FTIR), pembelauan sinar-X (XRD) dan mikroskop elektron transmisi (TEM). Keputusan FTIR menunjukkan penyingkiran unsur-unsur bukan selulosa pada setiap rawatan. CNC yang terhasil selepas proses hidrolisis selama 55 minit mempunyai darjah kehabluran yang tertinggi pada 81.15% melalui analisis XRD. CNC yang telah dihidrolisis selama 45 minit mempunyai panjang antara 50 dan 270 nm, manakala CNC yang telah dihidrolisis selama 55 minit mempunyai panjang sekitar 40 ke 370 nm.

In Chile, bamboo bushes of Chusquea quila have brought economic and ecological problems for decades in the south-central part of this country. On the other hand, this plant species was studied as a raw material for the production of nanofibrillated cellulose (CNF) and nanocrystalline cellulose (CNC), presenting an opportunity for sustainable and environmentally friendly management, positioning Chile as a Latin American country at the forefront of studies with nanotechnological approaches. The methodology applied to generate these nanostructures contemplated hydrolysis with sulfuric acid and oxalic acid, in addition to an intermediate stage of microfluidization to generate nanofibrillated cellulose. The products obtained showed morphological and topographic homogeneity in the scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. The diameter values of the particles ranged from 10 to 20 nanometers for the CNCs. Through Fourier transformed spectrophotometry (FTIR...

Laboratory mechanical softwood pulps
(MSP) and commercial bleached softwood kraft pulps
(BSKP) were mechanically fibrillated by stone grinding with a SuperMassColloider. The extent of fibrillation was evaluated by SEM imaging, water retention value (WRV) and cellulase adsorption. Both lignin content and mechanical treatment significantly affected deconstruction and enzymatic saccharification of fibrillated MSP and BSKP. Fibrillation of MSP and BSKP cell walls occurs rapidly and then levels off; further fibrillation has only limited effect on cell wall
breakdown as measured by water retention value and cellulase adsorption. Complete (100 %) saccharification can be achieved at cellulase loading of 5 FPU/g glucan for BSKP after only 15 min fibrillation with energy input of 0.69 MJ/kg. However, the presence of
lignin in MSP affects the extent of fibrillation producing fibrils mainly above 1 lm. Lignin binds nonproductively to cellulases and blocks cellulose thereby reducing its accessibility. As a result, the cellulose
saccharification efficiency of MSP fibrils (6 h of fibrillation, energy input of 13.33 MJ/kg) was only 55 % at same cellulase loading of 5 FPU/g glucan.

Nanocelluloses (NCs) have remarkable mechanical properties
and contain abundant surface functional groups that can be
modified or cross-linked with other materials. They have been
widely used as an environment-friendly reinforcing agent in
polymer composites. However, for applications that are carried
out in humid environments or aqueous suspensions, hydrophilicity
of NCs lower their mechanical integrity. Hence, cross-linking
techniques have been investigated in recent years for preparing
NC-based materials that are dimensionally stable under
humid or aqueous environments and have better physicochemical
properties. This Minireview examines the quickly
growing field of cross-linked NC-based materials, which have
many benefits including improved aqueous, structural, mechanical,
and thermal stability. In addition, the potential application
of cross-linked NC-based materials in adsorption of
heavy metal is discussed.

Cellulose is the most abundant and renewable natural semi-crystalline polysaccharide. This biopolymer is an inexhaustible source of natural fibers (NFs), and valuable raw material for the production of microparticles of microcrystalline (MCC) and powdered cellulose (PC), as well as other cellulose micro-products, which are widely used in biomedicine, production of food additives, plastics, and other materials. In addition, cellulose has a nano-fibrillar architecture that promotes the release of free cellulose nanofibers (CNFs) and nanocrystals (CNCs). This review article describes the preparation methods, structural characteristics, properties, and applications of different types of micro-(NFs, MCC, and PC) and nano-cellulose (CNFs, CNCs). Two main shortcomings hindering the wide application of various types of Nano cellulose (NC) were discovered, such as high production expenses and the difficulty of competing with commercial types of micro-cellulose. To reduce the production cost of NC, a waste-free technology can be used, which allows completely utilize materials and chemicals, and produce cheap nanocrystalline aggregates (NCA) with zero emission of liquid and solid waste. Due to the low cost, such a nanostructured product, NCA, will be quite competitive with commercial micro-celluloses (MCC, PC, etc.) and can be used, e.g., as filler and thickener.

This study proposed a layer-by-layer technique on the hard CNCs/hydroxyapatite (HAP) matrix using biodegradable and biocompatible chitosan and hyaluronic acid (HA). Inspired by the mineralized collagen in human bone, the CNCs/HAP matrix was synthesized by a facile in situ HAP coating on the CNCs fibers. The chemical and crystalline structure of the CNCs/HAP matrix was investigated with FTIR, XRD, HRTEM, and SAED. The surface of the CNCs/HAP matrix was analyzed by AFM which showed a flat structure with a roughness of 23.12 nm, however, the surface roughness increased to 56.09 nm with the assembly of chitosan and HA. After the LBL assembly, the surface hydrophilicity of the CNCs/HAP films was improved. Moreover, the CNCs/HAP matrix showed enhanced mechanical property than pure CNCs matrix. Although there is compromise in the mechanical property after the LBL assembly, it is anticipated its bioaffinity and biocompatibility will increase with the incoporation of chitosan and HA.

The production of cellulose nanofibers promotes the utilization of plant residues that are generated in agro-industries during food processing. The utilization of these plant by-products reduces environmental contamination. Cellulose nanofibers are used in several sectors, including the drug, food, and animal nutrition industries. Many sources of nanofibers used in animal diets can be used as potential fiber substitutes after being processed to improve efficiency. For instance, including nanometric particles of plant fibers (&lt;100 nm) in animal feed may provide excellent physical properties such as high reactivity, a large surface area, and improved nutrient absorption from the diet. Nanotechnology improves the characteristics of fibers that are important for gastrointestinal transit and their utilization as energy sources and substrates for microbial fermentation in the digestive tract of animals. Nanofibers can improve the synthesis of volatile fatty acids and the blood lipid pr...

Research into artificial bone scaffolds has increased substantially over the past decade as current solutions have significant limitations. Inspired by mineral hydroxyapatite (HAP) in natural bone, this study developed a facile in situ HAP coating on cellulose nanocrystals (CNCs) matrix followed by a crosslinking reaction. By changing the amount of CNCs added to a simulated body fluid (SBF), HAP content in the nanocomposite could be controlled between 0 and 40.1%, with a HAP coating thickness of ∼10 nm. Moreover, CNCs/HAP was crosslinked with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) and polyethylene glycol (PEG) to enhance its water stability and mechanical properties. FTIR and NMR analysis revealed that crosslinking happened via an esterification reaction between CNCs, HAP, PMVEMA, and PEG. Compression strength of the scaffolds showed a result as high as 41.8 MPa, almost 20 times of scaffold prepared by just mixing CNCs and HAP. Further investigations revealed that this scaffold was highly porous (as high as 91.0%) and lightweight (with a density between 60-70 mg/cm 3 ). Interestingly, this composite showed good biocompatibility as it can stabilize BSA protein, suggesting a promising material as a bone scaffold.

Thanks to their unique properties, such as (i) renewability,
(ii) high aspect ratios, (iii) low density, (iv) biodegradability,
(v) high strength, and (vi) stiffness, there have been many
reports in recent years detailing the isolation and functionalization
of cellulose nanowhiskers from cellulose. Moreover, nanocellulose
can be produced in large quantities in a cost-effective
manner and can be easily functionalized due to its high density
of hydroxy groups. In the present work, alkynyl-dendrons of the
PAMAM family were covalently attached to azide-functionalized
cellulose nanocrystals by click chemistry (Huisgen cycloaddition).
The resulting cycloadducts were then used as templates
for the preparation of stable and monodispersed gold nanoparticles
in aqueous media. The catalytic capabilities of these hybrid
materials were studied in the sodium borohydride mediated
reduction of 4-nitrophenol to 4-aminophenol, which
served as a model reaction.

The main focus this research involved the absorption spectroscopy of nanocellulose doped polymer dispersed liquid crystal (PDLC). the nanomaterial doped PDLC have superior performance relative to conventional PDLCs materials due to their high strength & high stiffness in polymer reinforcement. Nano cellulose doped PDLCs with different composition have been studied by the means of UV-VIS (Ultravoilet visible spectroscopy). A solution composed of methylmeta- acrylate (MMA) & nematic LC (5CB) were prepared by solution casting toluene. results were interpreted in terms of infrared absorption spectrum, optical properties & solubility of LC in polymer matrix.

Heavy metals are toxic substances that pose a real danger to humans and organisms, even at low concentration. Therefore, there is an urgent need to remove heavy metals. Herein, the nanocellulose (NC) was synthesized by the hydrolysis of cellulose using sulfuric acid, and then functionalized using polypyrrole (ppy) through a polymerization reaction to produce polypyrrole/nanocellulose (ppy/NC) nanocomposite. The synthesized nanocomposite was characterized using familiar techniques including XRD, FT-IR, SEM, TEM, and TGA. The obtained results showed a well-constructed nanocomposite with excellent thermal stability in the nano-sized scale. The adsorption experiments showed that the ppy/NC nanocomposite was able to adsorb hexavalent chromium (Cr(VI)). The optimum pH for the removal of the heavy metal was pH 2. The interfering ions showed minor effect on the adsorption of Cr(VI) resulted from the competition between ions for the adsorption sites. The adsorption kinetics were studied usin...

Cellulose nanomaterials have attracted a great deal of interest as sustainable alternatives to nonrenewable or fossil fuelderived materials, particularly in composite applications. Cellulose nanofibrils (CNF) are most often derived from wood sources through energy-intensive and costly mechanical fibrillation processes. In this study, recycled cardboard, referred to as old corrugated cardboard (OCC), was investigated as an alternate CNF source. OCC is a recycled material that can be obtained at one-tenth the cost of the commonly used bleached softwood Kraft pulp and can be refined to similar levels with nearly one-half of the energy consumption. Additionally, the distinct composition and morphology of OCCderived CNF provides a more favorable fiber−matrix interface and better reinforcement capabilities of the cellulose nanofibrils in polymer matrices, displaying an over 70% increase in tensile modulus at a loading of 40 wt % with no decrease in tensile strength. When paired with biobased poly(L-lactide) (PLLA), OCC-derived CNF is proven to be an attractive low-cost and low-energy reinforcing agent for sustainable, high performance nanocomposites.

The utilization of lignocellulosic biomass in various applications has a promising potential as advanced technology progresses due to its renowned advantages as cheap and abundant feedstock. The main drawback in the utilization of this type of biomass is the essential requirement for the pretreatment process. The most common pretreatment process applied is chemical pretreatment. However, it is a non-eco-friendly process. Therefore, this review aims to bring into light several greener pretreatment processes as an alternative approach for the current chemical pretreatment. The main processes for each physical and biological pretreatment process are reviewed and highlighted. Additionally, recent advances in the effect of different non-chemical pretreatment approaches for the natural fibres are also critically discussed with a focus on bioproducts conversion.

In this study, porous aerogels were prepared by directional freeze-drying via cross-linking cellulose nanocrystals (CNCs) with poly(methyl vinyl ether-co-maleic acid) (PMVEMA) and poly(ethylene glycol) (PEG). The thermal properties and physical adsorption performance toward cation methylene blue dye of the obtained CNC aerogels were investigated. The maximum degradation temperature was increased from 324 • C of CNCs to 355 • C of cross-linked CNC aerogels. The dye adsorption isotherm results showed that the maximum methylene blue adsorption capacity of CNC aerogels was 116.2 mg g −1 , according to the Langmuir model, which was mainly due to the electrostatic attractions between negatively charged carboxyl groups or sulfonate groups on the CNC aerogles and cation MB molecules. The reusability test showed that the CNC aerogels contained the same dye adsorption performance in five adsorption/desorption cycles. Overall, this study described an ideal alternative for water purification with high dye adsorption capacity and enhanced physical performance.