By Zhao Xinhua

Nowadays, the application of green,renewable and sustainable materials has become increasingly important for producing various high—value products with low environmental impact. Because such materials turn out to be an alterna—tive solution to the ever—depleting non—renewable sources, environmental pol—lution, global warming, and energy crisis.Nanocellulose is one of the most promi—nent green materials of modern times.

Nanocellulose, which can currently be produced in industrial scale at the tons per day, can be employed in several fields in our life, such as nanocomposite materials, biomedical products, wood adhesives, supercapacitors, template for electronic components, batteries, cata—lytic supports, electroactive polymers,continuous fibers and textiles, food coatings, barrier/separation membranes,antimicrobial films, paper products,cosmetic, cements, and more emerging uses.

Nanocellulose—reinforced composites possess outstanding properties due to the presence of nanosize filler, which makes them potential candidates to replace conventional synthetic polymer composites. It was noted that the exceptional reinforcing capability of nanocellulose is attributable to its light—weight, high stiffness,and superior mechanical strength. Nanocellulose has established to be a substantial reinforcement. The dynamic mechanical analy—sis demonstrated that the loss tangent (tanδ) at 60°C is lower for the composite containing 5 wt.% of rice husk—nanocellulose and 25 wt.% carbon black compared to the composite containing 30 wt.%carbon black, implying that rice husk—nanocellulose contributes to low rolling resistance, which is a crucial parameter for green tire applications. Thus, the study has proven the potential replacement of carbon black with nanocellulose.

Modern Synthesis’ microbial textile tech leverages bacteria to transform sugar from agricultural waste into nanocellulose. The“microbial weaving” process mimics the warp—and—weft tech—nique of traditional weaving to create a customizable biomaterial in roughly 10 to 14 days. Staff at Modern Synthesis create a scaf—fold, using robotics to place fibers in the desired shape or structure.Genetically modified bacteria grow around those structures to create the final material. Similar to 3D printing — and unlike tradi—tional weaving — pieces can be designed to shape, which means no scraps of leftover material and therefore no waste. So far, Modern Synthesis has been able to build the upper part of a shoe using this process. The company says it has delivered its materials to a “key sportswear customer” for prototyping. It plans to eventually lever—age microbes to displace a variety of animal— and petrochemical—derived leathers, textiles, and films.

In 2022, Professor Qin Xiaohong and Professor Wang Lim—ing from Donghua University proposed an advanced fabrication approach combining coagulation—bath electrospinning and self—assembly strategies to efficiently and continuously fabricate CNT/PEDOT:PSS thermoelectric nanofiber yarns with high stretchability(～350%) and seamability. During the spinning process, the non—solvent induced phase separation and self—assembly effect result in a large amount of CNT/PEDOT:PSS loaded on each individual nanofiber. Since the thermoelectric material is loaded inside the yarn rather than simply coated on the surface, it exhibits excel—lent mechanical stability. In addition, based on the thermoelectric effect and seamability of the yarns, they can be integrated into gloves and masks for cold/heat source identification and human respiration monitoring in self—powered mode. Moreover, the self—powered strain sensor composed of the yarn shows corresponding thermovoltage changes for different strains, which can be used to optimize basketball players’ shooting percentage. These unique features make the thermoelectric nanofiber yarn show broad prospects in smart wearable fields such as wearable generators,breathing monitoring, and exercise optimization.

Researchers at Sweden’s Chalmers University of Technology in collaboration with India’s Malaviya Na—tional Institute of Technology, Jaipur have developed a new method that can easily purify contaminated water using a cellulose—based material. Going from discharging completely untreated water to removing 80 percent of the pollutants is a huge improvement,and means significantly less destruction of nature and harm to humans. Researchers also see great opportu—nities to use cellulose nanocrystals for the treatment of other water pollutants than dyes.

Nanocellulose has caused a technological revo—lution in the paper industry. It not only reduces the weight and quality of paper, but also reduces the annual consumption of forests. The special pack—aging of nanocellulose has the function of barrier performance and long—lasting preservation of fresh food, and the market demand is very large. Nano—cellulose is often added to cosmetics for a lubricated touch. In addition, nanocellulose can not be digested and absorbed by human body, but can promote intestinal peristalsis and improve the ecological bal—ance of intestinal flora. When added to baked goods,it can be used to make slimming food or functional food. Such as bagasse as raw materials, preparation of microcrystalline cellulose and nanocellulose, can be used to make dietary fiber bread.

The global production capacity of nanocellulose is mainly concentrated in North America, Europe,Asia—Pacific and other regions, among which Eu—ropean and American enterprises occupy the main share of high—end nanocellulose market by virtue of their advantages of advanced technology, pre—re—lease bureau and perfect equipment. Nanocellulose has a broad application prospect. However, currently,due to technical limitations, the global nanocellulose production scale is small, and its application is still in the initial stage. There is a large space for the product to be practical and commercialized. Prices of nanocellulose material are expected to decline as cheaper pulp sources are used, extraction processes are optimized and global productivity increases.