Preparation of PVA@PEI@BAC@CNC composite nanofibrous film with high efficiency filtration for PM2.5

It is still a challenge to prepare a water-and polymer-based electrospun air filter film with high efficiency filtration,low pressure drop,and good mechanical properties.To address this issue,polyvinyl alcohol(PVA)was employed as the main material,mixing polyethyleneimine(PEI),bamboo-based activated carbon(BAC)and cellulose nanocrystal(CNC)to construct the air filter film by electrostatic electrospinning.In this system,the negatively charged BAC and CNC are fixed in the system through bonding with the positively charged PEI,showing a double adsorption effect.One is the mechanical filtration of the porous network structure constructed by PVA@PEI electrospun nanofibers,and the other is the electrostatic adsorption of PM2.5 on the surface of BAC and CNC.It is significant that the resulting composite air filter displays a high filtration efficiency of 95.86%,a pressure drop of only 59 Pa,and good thermal stability.Moreover,the introduced methyltrimethoxysilane(MTMS)endows it with good water-resistance.Given these excellent performances,this system can provide theoretical and technical references for the development of water-and polymerbased electrospun air filter film.

Facile preparation and property analyses of L-CNc/SiO_(2)-based composite superhydrophobic coating

In recent years,superhydrophobic coatings have received extensive attention due to their functions of waterproof,antifouling,self-cleaning,etc.However,wide applications of superhydrophobic coatings are still affected by their disadvantages of complex preparation,low mechanical properties,and poor ultraviolet(UV)resistance.In this study,cellulose nanocrystal containing a small amount of lignin(L-CNC)/SiO_(2)composite particles were usedas the main material,polydimethylsiloxane(PDMS)as the adhesive and perfluorooctyltrichlorosilane(FOTS)as the modifier to prepare superhydrophobic coatings by a one-step spray method.The resulted coating showed excellent superhydrophobicity(water contact angle(WCA)of 161°and slide angle(SA)of 7)and high abrasion resistance(capable of withstanding 50 abrasion cycles under the load of 50 g).Moreover,it still maintained good superhydrophobicity after 5 h of exposure to the UV light(1000 W),displaying its good UV resistance.This study provides theoretical and technical referencefor thesimple preparationof organic-inorganic composite superhydrophobic coatings with high abrasion resistance and good UV resistance,which is beneficial to improving the practicability and broadening the application scope of superhydrophobic coatings.