Cellulose nanomaterials (CNs) are of increasing interest due to their appealing inherent properties such as bio-degradability, high surface area, light weight, chirality and the ability to form effective hydrogen bonds across the cellulose chains or within other polymeric matrices. Extending CN self-assembly into multiphase polymer structures has led to useful end-results in a wide spectrum of products and countless innovative applications, for example, as reinforcing agent, emulsion stabilizer, barrier membrane and binder. In the current contribution, after a brief description of salient nanocellulose chemical structure features, its types and production methods, we move to recent advances in CN utilization as an ecofriendly binder in several disparate areas, namely formaldehyde-free hybrid composites and wood-based panels, papermaking/coating processes, and energy storage devices, as well as their potential applications in biomedical fields as a cost-effective and tissue-friendly binder for cartilage regeneration, wound healing and dental repair. The prospects of a wide range of hybrid materials that may be produced via nanocellulose is introduced in light of the unique behavior of cellulose once in nano dimensions. Furthermore, we implement some principles of colloidal and interfacial science to discuss the critical role of cellulose binding in the aforesaid fields. Even though the CN facets covered in this study by no means encompass the great amount of literature available, they may be regarded as the basis for future developments in the binder applications of these highly desirable materials.

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Cellulose Nanomaterials—Binding Properties and Applications: A Review

Wound healing has been intensely studied in order to develop an “ideal” technique that achieves expeditious recovery and reduces scarring to the minimum, thus ensuring function preservation. The classic approach to wound management is represented by topical treatments, such as antibacterial or colloidal agents, in order to prevent infection and promote a proper wound-healing process. Nanotechnology studies submicroscopic particles (maximum diameter of 100 nm), as well as correlated phenomena. Metal nanoparticles (e.g., silver, gold, zinc) are increasingly being used in dermatology, due to their beneficial effect on accelerating wound healing, as well as treating and preventing bacterial infections. Other benefits include: ease of use, less frequent dressing changes and a constantly moist wound environment. This review highlights recent findings regarding nanoparticle application in wound management.

https://www.mdpi.com/1996-1944/12/13/2176/pdf

Nanomaterials for Wound Healing and Infection Control.

https://pubs.rsc.org/en/content/articlepdf/2019/GC/C8GC03746A

Future opportunities for bio-based adhesives – advantages beyond renewability

The use of polysaccharide-based materials presents an eco-friendly technological solution, by reducing dependence on fossil resources while reducing a product’s carbon footprint, when compared to conventional plastic packaging materials. This review discusses the potential of polysaccharides as a raw material to produce multifunctional materials for food packaging applications. The covered areas include the recent innovations and properties of the polysaccharide-based materials. Emphasis is given to hemicelluloses, marine polysaccharides, and bacterial exopolysaccharides and their potential application in the latest trends of food packaging materials, including edible coatings, intelligent films, and thermo-insulated aerogel packaging.

Prospect of Polysaccharide-Based Materials as Advanced Food Packaging.

Cellulose nanomaterials from plant fibre provide various potential applications (i.e., biomedical, automotive, packaging, etc.). The biomedical application of nanocellulose isolated from plant fibre, which is a carbohydrate-based source, is very viable in the 21st century. The essential characteristics of plant fibre-based nanocellulose, which include its molecular, tensile and mechanical properties, as well as its biodegradability potential, have been widely explored for functional materials in the preparation of aerogel. Plant cellulose nano fibre (CNF)-based aerogels are novel functional materials that have attracted remarkable interest. In recent years, CNF aerogel has been extensively used in the biomedical field due to its biocompatibility, renewability and biodegradability. The effective surface area of CNFs influences broad applications in biological and medical studies such as sustainable antibiotic delivery for wound healing, the preparation of scaffolds for tissue cultures, the development of drug delivery systems, biosensing and an antimicrobial film for wound healing. Many researchers have a growing interest in using CNF-based aerogels in the mentioned applications. The application of cellulose-based materials is widely reported in the literature. However, only a few studies discuss the potential of cellulose nanofibre aerogel in detail. The potential applications of CNF aerogel include composites, organic-inorganic hybrids, gels, foams, aerogels/xerogels, coatings and nano-paper, bioactive and wound dressing materials and bioconversion. The potential applications of CNF have rarely been a subject of extensive review. Thus, extensive studies to develop materials with cheaper and better properties, high prospects and effectiveness for many applications are the focus of the present work. The present review focuses on the evolution of aerogels via characterisation studies on the isolation of CNF-based aerogels. The study concludes with a description of the potential and challenges of developing sustainable materials for biomedical applications.

A Review on Plant Cellulose Nanofibre-Based Aerogels for Biomedical Applications.

Cellulose nanofibrils (CNF) were spun into filaments directly from suspension without the aid of solvents. The influence of starting material properties and drying temperature on the properties of filaments produced from three different CNF suspensions was studied. Refiner-produced CNF was ground using a microgrinder at grinding times of 50 and 100 minutes. Filament spinning was performed using a syringe pump-heat gun setting at three drying temperatures of 210 °C, 320 °C and 430 °C. The structure of starting CNF materials was first evaluated using a combination of optical and atomic force microscopy (AFM) techniques. Surface free energy analysis and attenuated total reflectance—Fourier transform infrared spectroscopy (ATR–FTIR) were used to study changes in hydrophobicity due to grinding. Morphology of the filaments was studied using SEM micrographs. The influence of different drying temperatures and grinding times on mechanical properties of the CNF filaments were further investigated through tensile tests and results were compared using statistical analysis .It was observed that drying temperature did not significantly influence the tensile properties of the filaments while cellulose nanofiber suspension type (grinding time) had a significant influence and improved mechanical properties. FTIR results confirmed an increase in crystallinity index and decrease in hydroxyl group availability due to grinding.

Dry-Spun Neat Cellulose Nanofibril Filaments: Influence of Drying Temperature and Nanofibril Structure on Filament Properties

Reinforcement of natural fiber yarns by cellulose nanomaterials: A multi-scale study

Utilization of cellulose nanofibrils (CNF) for filament production is a comparatively new approach, which can broaden nanocellulose applications by providing continuous long filaments suitable for composite and textile applications. Methods are proposed for the spinning of filaments from cellulose nanofibril suspensions, which are mainly categorized into two groups, i.e. dry-spinning and wet-spinning. For the dry-spinning method, the substrate on which the filament is spun will have a significant influence on the properties of the filament because the as-spun CNF will initially contact it. In this work, the influence of different collection substrates on the properties of CNF filament was studied. Filaments with an average diameter of 0.1 mm were spun on different collection substrates including Teflon tape, Teflon film and glass. The influence of adding oil, as a friction modifier, on the surface properties of the substrate and the structure of the resultant filaments was evaluated. Wettability of each substrate in the absence of oil, and the presence of a thin layer and a thick layer of oil was studied. Circularity of the filaments was measured using image analysis of the cross sections and was correlated with the surface properties of the substrates. It was found that while the surface properties of the collection substrate were related to the uniformity and cross section circularity of the filaments, those spun on a thick layer of oil had the best circular shape irrespective of the substrate material. The results of this study can be used to optimize dry-spinning of CNF filaments.

Shokoofeh Ghasemi

Papers

Cellulose Nanomaterials—Binding Properties and Applications: A Review

Dry-Spun Neat Cellulose Nanofibril Filaments: Influence of Drying Temperature and Nanofibril Structure on Filament Properties

Reinforcement of natural fiber yarns by cellulose nanomaterials: A multi-scale study

Effect of wettability and surface free energy of collection substrates on the structure and morphology of dry-spun cellulose nanofibril filaments

Flexible polyurethane foams reinforced with organic and inorganic nanofillers