Cellulose is the most abundant biopolymer on Earth, found in trees, waste from agricultural crops and other biomass The fibres that comprise cellulose can be broken down into building blocks, known as fibrillated cellulose, of varying, controllable dimensions that extend to the nanoscale Fibrillated cellulose is harvested from renewable resources, so its sustainability potential combined with its other functional properties (mechanical, optical, thermal and fluidic, for example) gives this nanomaterial unique technological appeal Here we explore the use of fibrillated cellulose in the fabrication of materials ranging from composites and macrofibres, to thin films, porous membranes and gels We discuss research directions for the practical exploitation of these structures and the remaining challenges to overcome before fibrillated cellulose materials can reach their full potential Finally, we highlight some key issues towards successful manufacturing scale-up of this family of materials

Developing fibrillated cellulose as a sustainable technological material.

This review gives an overview of recent advances in the potential applications of superhydrophobic materials. Such properties are characterized by extremely high water contact angles and various adhesion properties. The conception of superhydrophobic materials has been possible by studying and mimicking natural surfaces. Now, various applications have emerged such as anti-icing, anti-corrosion and anti-bacterial coatings, microfluidic devices, textiles, oil–water separation, water desalination/purification, optical devices, sensors, batteries and catalysts. At least two parameters were found to be very important for many applications: the presence of air on superhydrophobic materials with self-cleaning properties (Cassie–Baxter state) and the robustness of the superhydrophobic properties (stability of the Cassie–Baxter state). This review will allow researchers to envisage new ideas and industrialists to advance in the commercialization of these materials.

Recent advances in the potential applications of bioinspired superhydrophobic materials

Phase change materials (PCM) are characterized for storing a large amount of thermal energy while changing from one phase to another (generally solid-liquid states) at a specific temperature and presenting a high specific heat of phase change process. PCMs can be classified as organic, inorganic and eutectic. Such materials present some limitations, including subcooling, phase segregation, flammability, low thermal conductivity and thermal instability, among others. In order to overcome these problems, encapsulation of PCMs is being successfully developed, providing decreased subcooling, large heat transfer area, and controlling the volume change of the storage materials when the phase transition occurs. A considerable amount of studies has been published in the field of encapsulation methods for organic PCMs. Nevertheless, the information available on inorganic PCMs is scattered. Furthermore, the influence of the encapsulation techniques on thermophysical properties of PCMs is not reported in these reviews most of the time. Hence, the aim of this review is to summarize the encapsulation and characterization techniques for inorganic PCMs and to provide the analysis about the influence of synthesis parameters on thermophysical properties of encapsulated PCMs. Two principal types of encapsulated inorganic PCMs were found: core-shell PCMs (core-shell EPCMs) and shape stabilized PCMs (SS-PCMs). Classification of encapsulation methods of core-shell EPCMs and SS-PCMs are reported in this work. Among all the microencapsulation methods, inverse Pickering emulsion, electroplating, solvent evaporation–precipitation method and mechanical packaging are the most common methods described in the literature for the production of core-shell EPCM. On the other hand, for SS-PCMs, mainly sol-gel process, infiltration and impregnation encapsulation methods were found. Scientific works report a reduction in the heat of phase change for core-shell EPCMs. This is mostly because of the low content of salt in the final material. Moreover, an improvement of thermal conductivity was procured for SS-PCMs. Finally, PCM percentage, particle size, stirring rate, type of crosslinking agent and solvent properties were established as principal factors influencing the final properties of the encapsulated materials. For the best of our knowledge, this is the first profound review of encapsulation techniques for inorganic PCM.

A review on encapsulation techniques for inorganic phase change materials and the influence on their thermophysical properties

https://www.cell.com/joule/pdf/S2542-4351(20)30089-1.pdf

Advanced Textiles for Personal Thermal Management and Energy

An overview on antimicrobial and wound healing properties of ZnO nanobiofilms, hydrogels, and bionanocomposites based on cellulose, chitosan, and alginate polymers

A simple chemical synthetic route was designed to prepare zinc oxide nanoparticles (ZnO-NPs) by using sodium alginate as anti-agglomeration agent in the presence of sodium hydroxide as alkali. Next, surface modification of ZnO-NPs with SiO2 nanoparticles was achieved as per to sol-gel process. Further enhancing of the multifunctional properties of SiO2@ZnO-NPs was conducted successfully thanks to (aminopropyl)triethoxysilan (APTES) and vinyltriethoxysilan (VTES) which, in turns, increase the affinity of the SiO2@ZnO-NPs nanocomposite towards glycosidic chains of cotton fabrics. Thorough characterizations of synthesized ZnO-NPs, SiO2@ZnO-NPs, SiO2@ZnO-NPs/APTES and SiO2@ZnO-NPs/VTES were conducted by the making use of well advanced techniques such as FT-IR, XRD, TEM, DLS and SEM-EDX. The data obtained clarified the formation of an interfacial chemical bond between ZnO and SiO2 as affirmed by FT-IR and XRD analysis. In addition, the results revealed by TEM, zeta sizer and SEM-EDX techniques, declared that the amorphous layers of SiO2, APTES or VTES evenly coated the surface of ZnO-NPs. For these nanocomposites, the work was extended to render cotton fabrics multifunctional properties such as antibacterial and UV protection with high durability even after 20 washing cycles using pad dry cure method. Taking the advantages of the silane compounds terminated by active groups such as OH, NH2, etc., open the door for further functionalization of the cotton fabrics' surfaces by durable multifunctional agents applied in various applications.

Amina L. Mohamed

Papers

Surface modification of SiO 2 coated ZnO nanoparticles for multifunctional cotton fabrics

Development of multifunctional modified cotton fabric with tri-component nanoparticles of silver, copper and zinc oxide.

Enhancement of flame retardancy and water repellency properties of cotton fabrics using silanol based nano composites.

Development of durable superhydrophobic cotton fabrics coated with silicone/stearic acid using different cross-linkers

Laminating of chemically modified silan based nanosols for advanced functionalization of cotton textiles.