Heat Soaking Pretreatment for Greener Production of Phosphorylated Cellulose Nanofibrils with Higher Charge Density

Abstract

Phosphorylated cellulose nanofibrils (PCNFs) made from woody biomass have aroused immense interest because of their promising applications in various fields, including flame retardancy, adsorption, and separation. However, traditional production methods show high chemical and energy consumption, while the obtained PCNFs have lower charge density. In this study, PCNFs with higher charge density (2.09−3.79 mmol•g −1 ) were produced by tuning heat soaking pretreatment of cellulose fibers in phosphate salt and urea solutions, followed by curing and mechanical fibrillation. An optimized pretreatment can be achieved by heat-assisted soaking at 80 °C for 25 min, which was effective to produce PCNFs with greater performance (e.g., higher charge and crystallinity) compared to those of traditional methods. Furthermore, the optimized route is more sustainable with a substantial decrease in resource consumption including chemicals (33.6%), water (55.8%), and energy (65.3%), and the production costs would be saved by 62.0% in comparison with the traditional route. Such a sustainable and economic process has great potential in the industrial production of PCNFs.

Effect of Amino Silicone Oil-Phosphorylation Hybrid Modification on the Properties of Microcellulose Fibers

“…On the one hand, the ASOP hybrid modification not only occurred in the amorphous region but also at the edge of the crystalline region. On the other hand, the partial decomposition of the hydrogen bonding system in microcellulose led to an increase in the number of hydroxyl groups in the weaker hydrogen bonds [ 42 ], thus extending the amorphous region. Although the ASOP hybrid modification had a certain impact on the crystallinity of MCF, it did not change the cellulose I crystalline structure.…”

Shear-Induced Fabrication of Cellulose Nanofibril/Liquid Metal Nanocomposite Films for Flexible Electromagnetic Interference Shielding and Thermal Management

“…Ultrapure water was used to prepare all aqueous solutions. The PCNF suspension was prepared by the chemical-mechanical method according to our previous study and was diluted to 0.45 wt % …”

“…To reduce electromagnetic radiation pollution and meet the requirements of the next generation of portable, wearable, and flexible electronic devices, the development of ultrathin, high-performance, and highly stable EMI shielding materials is a promising approach. Reasonable building blocks, including polymer matrix and conductive fillers, as well as structure design are of great importance for the construction of EMI shielding materials. , Cellulose nanofibrils (CNFs), alternatives to traditional fossil materials, are promising candidates to work as desirable building blocks for advanced EMI shielding materials, due to their sustainability, high strength, high aspect ratio, and biocompatibility. − To date, substantial progress has been made in CNF composites for EMI shielding field, where CNFs generally are served as substrate or nano reinforcing agent. − High conductivity and excellent mechanical performance have been achieved in composites containing CNFs, conductive fillers and other polymers. , As a member of CNF family, phosphorylated CNFs (PCNFs) have higher charge content, better stability, and complexation ability with multivalent ions . Besides, they become gel at very low concentrations and the resulting composites exhibit superior mechanical properties compared with other types of CNFs, thus they have gradually received more attention. , …”

Pre-phosphorylation for facile production of phosphorylated cellulose nanocrystals with high charge content: an optimised design and life cycle assessment

“…7 Notably, Chen et al removed the filtration process before drying, thereby increasing the charge content of P-CNFs (2.09–3.79 mmol g −1 ), decreasing environmental burdens and production costs with less chemical reagents and energy consumption. 25 However, pre-phosphorylation has not been reported for P-CNC production yet. As a bio-based material with high crystallinity, 26 microcrystalline cellulose (MCC) is generally prepared by acid hydrolysis.…”