Preparation Of Porous Nanocellulose Membrane And Their Properties

Since the reform and opening up,the phenomenon of rapid development of China’s industrial experience,resulting in the scarcity of energy and resources as well as the destruction of the natural environment has drawn widespread attention.Water resources play an important role in human production and life.Thus,it is a challenge to intake outdoor drink water during the emergency events.Combining antibacterial ability to portable membranes should be promising to solve this issue.At the same time,air pollution has also been gradually taken seriously by people in recent years,and the term smog has been constantly mentioned.Airborne particulate matter(PM)pollution in air seriously affects public health.It is more attractive to generating clean air indoor during PM polluted haze days under natural passive ventilation through window screens.As a kind of renewable nano-biomaterials,nanocellulose has drawn more and more attention from all walks of life.With the gradual depletion of coal and oil resources and the deteriorating environment,nanocellulose has broad prospects for development.Cellulose is showing great potential in the field of nanomaterials.The nanocellulose prepared by the cellulose is a green and environment-friendly nanomaterial.Nanocellulose is excellent in high purity,high strength and high Young’s modulus.In addition,it also has a high optical,electrical,magnetic and rheological properties,coupled with its features of light weight,biodegradability,biocompatibility and reproducibility of biological materials,cellulose is being displayed out of its huge potential in the field of nanomaterials.Preparation of nanocellulose is of great significance to the development of new materials.Therefore,due to biocompatibility,biodegradability and renewable resources,the utilization of cellulose in environmental energy certainly contributes to environmental protection and sustainable development.Specific studies are as follows:1.Using cellulose as raw material,TEMPO(2,2,6,6-tetramethylpiperidine oxide)/NaClO as oxidation system,under mild conditions(room temperature or slightly above room temperature environment)to preparation of nanocellulose,.The composite membrane with excellent antimicrobial properties can be prepared by loading silver nano-particles and can be used for field water treatment in emergency events.The study found that the 710 nm thick Ag NPs/CNFs thin composite membrane containing 3.6 wt%Ag nanoparticles had an 86%rejection of 5 nm nanoparticles with a water flux approaching 1000 L m-2h-1 · bar-1,which has great application prospects for outdoor water intake during emergency events.2.On the basis of the above,the preparation conditions were adjusted and the surface modification was used.A hydrophobic porous CNFs thin layer was formed on a stainless steel screen(300 meshes,pore size of 48 μm)through a simple filtration-assisted gelation process and polydimethylsiloxane(PDMS)coating.When used as a window screen,the prepared CNFs/stainless steel screen demonstrates sieving-based highly efficient PM2.5 blocking,fast air permeability,and long-term durability under natural passive ventilation with relative humidity in the range of 45%to 93%,especially in southern moisture heavier weather.