Zhibin He

Stability and efficiency improvement of ASA in internal sizing of cellulosic paper by using cationically modified cellulose nanocrystals

Alkenyl succinic anhydride (ASA) is a reactive sizing agent that can impart good water repellence to paper by decreasing the wettability of the cellulose fibers. However, ASA can undergo hydrolysis, which is detrimental to the ASA sizing efficiency. In order to improve the ASA emulsion stability and ASA sizing efficiency, we used cationically modified cellulose nanocrystals (CNCs) to stabilize the cationic starch-emulsified ASA. Transmission electron microscope observation revealed that ASA droplets were well shielded by both the cationic CNCs and cationic starch, which may be responsible for the improved stabilization of ASA. The Hercules size test sizing degree, contact angle and particle size measurements demonstrated that cationic CNCs–ASA sized paper exhibited improved results in comparison with the control (without cationic CNCs under otherwise the same conditions). Furthermore, the resulting cationic CNCs–ASA system can improve the tensile index and burst index of the sized paper.

Recent developments of cellulose materials for lithium-ion battery separators

This paper reviews the recent developments of cellulose materials for lithium-ion battery separators. The contents are organized according to the preparation methods such as coating, casting, electrospinning, phase inversion and papermaking. The focus is on the properties of cellulose materials, research approaches, and the outlook of the applications of cellulose materials for lithium-ion batteries.

Methods to increase the reactivity of dissolving pulp in the viscose rayon production process: a review

Cellulose is a green and sustainable feedstock that can be used for manufacturing many bio-based products. Dissolving pulps, the main source of high-purity cellulose, have been extensively used in the production of cellulose-based products. The reactivity of dissolving pulp is a critical property because a high reactivity can decrease the production cost and environmental impact of application processes, in particular for the viscose rayon production. This review discusses the factors which affect the reactivity of dissolving pulp, including raw materials, manufacturing processes, drying and oxidation. Various methods to increase the reactivity of dissolving pulp are discussed, and they include mechanical treatment, enzymatic treatment, caustic extraction, ionic liquid extraction, acid treatment, ozone treatment, thermal degradation, and their combinations. Their advantages and disadvantages are compared and analyzed. Finally, the practical implications of effective methods to improve the reactivity and the future of dissolving pulp are discussed.Graphical Abstract

Improvement of stability of tea polyphenols: a review

Tea polyphenols have received much attention from the pharmaceutical and food industries owing to their extraordinary antioxidant and antibacterial characteristics. However, tea polyphenols are very unstable in processing and storage, since they are sensitive to the environmental factors like temperature, light and pH. Therefore, the effective application of tea polyphenols requires a protective mechanism to maintain its activity. The utilization of compounded tea polyphenols, instead of raw materials, can potentially help to improve their stability. This review focuses on the summarization of the compounding technologies for tea polyphenols, including physical technologies, chemical-interfacial technologies and nano-scale compounding technologies. Of which, the emerging nano cellulose bio-carrier, as a promising technology, is particularly proposed.

Bio-polymer Substrates in Buccal Drug Delivery: Current Status and Future Trend

BACKGROUND This paper provides a critical review of biopolymer-based substrates, especially the cellulose derivatives, for their application in buccal drug delivery. Drug delivery to the buccal mucous has the benefits of immobile muscle, abundant vascularization and rapid recovery, but not all the drugs can be administered through the buccal mucosa (e. g., macromolecular drugs), due to the low bioavailability caused by their large molecular size. This shortfall inspired the rapid development of drug-compounding technologies and the corresponding usage of biopolymer substrates. METHODS Cellulose derivatives have been extensively developed for drug manufacturing to facilitate its delivery. We engaged in structured research of cellulose-based drug compounding technologies. We summarized the characteristic cellulose derivatives which have been used as the biocompatible substrates in buccal delivery systems. The discussion of the potential use of the rapidly-developed nanocellulose (NC) is also notable in this paper. RESULTS Seventy-eight papers were referenced in this perspective paper with the majority (sixty-five) published later than 2010. Forty-seven papers defined the buccal drug delivery systems and their substrates. Fifteen papers outlined the properties and applications of cellulose derivatives. Nanocellulose was introduced as a leading edge of nanomaterial with sixteen papers highlighted its adaptability in drug compounding for buccal delivery. CONCLUSION The findings of this perspective paper proposed the potential use of cellulose derivatives, the typical kind of biopolymers, in the buccal drug delivery system for promoting the bioavailability of the macromolecular drugs. Nanocellulose (NC) in particular was proposed as an innovative bio-binder/carrier for the controlled-release of drugs.