Preparation and Functional Design of Polyethyleneimine Reinforced Nanocellulose-based Aerogel

An aerogel electrode composed of conductive active materials based on nanocellulose aerogels can absorb more electrolytes,as well as enhance electron transport and ion diffusion channels.In the present study,aerogels with high strength were successfully prepared using 2,2,6,6-tetramethyl-1-piperidinyloxy free radical(TEMPO)-oxidized cellulose nanofibrils(CNF)as a raw material and polyethyleneimine(PEI)as a crosslinking agent.Simultaneously,functional electrode materials were prepared via self-assembly.Based on our findings,PEI can significantly improve the water and solvent solubility and enhance the wet strength and shape recovery ability of CNF aerogels.Meanwhile,the minimum density of the aerogel reached 0.0160 g/cm3,the maximum porosity was approximately 98.5%,and the maximum stress approximated 0.02 MPa.Furthermore,electrochemical tests revealed that after self-assembly of reduced graphene oxide(RGO)and polyaniline(PANI)solution,the mass specific capacitance of the functional composite aerogel was approximately 92 F/g and exhibited good chargedischarge performance.

Adsorption of Cu^(2+)by Crosslinked Graft Copolymers of Starch

With the use of acrylic acid(AA)as a monomer,humic acid(HA)and starch as raw materials,potassium persulfate(KPS)as initiator,and N,Ndimethylacrylamide(MBA)as a cross-linking agent,AA/HA/Starch graft copolymer was prepared and characterized by SEM and FT-IR.The effects of temperature,adsorption time,adsorbent dosage,pH value and Cu^(2+)initial concentration of the solution on the adsorption performance of the crosslinked graft copolymer were also investigated.The results showed that the Cu^(2+)adsorption capacity of the AA/HA/Starch graft copolymer increased firstly and then decreased with increasing adsorbent dosage and the initial pH value of Cu^(2+)solution.With the increase of Cu^(2+)initial concentration and the extension of adsorption time,the adsorption amount of Cu^(2+)increased rapidly and then stabilized.And it decreased slightly with the increase of temperature.At pH value of 5.5,temperature of 298 K,adsorbent dosage of 50 mg,adsorption time of 125 min,and 100 mL Cu^(2+)solution with Cu^(2+)initial concentration of 100 mg/L,the Cu^(2+)adsorption capacity of the crosslinked graft copolymer was 238 mg/g.The adsorption of Cu^(2+)by the adsorbent followed the pseudo-second-order kinetic equation and Langmuir isothermal adsorption model,and the adsorption was attached to monolayer chemical adsorption.This study proved that AA/HA/Starch graft copolymer could be used as an efficient adsorbent for the removal of harmful and toxic metal cations such as Cu^(2+)from industrial wastewater.

Transparent Photochromic Wood Composites Incorporating AgBr Nanoparticles for UV-shielding Applications

Transparent wood(TW)is a wood-based biomaterial with several advantages,such as high optical transmittance,low thermal conductivity,and tunable haze.TW is functionalized according to its transparency to broaden its applications in different fields.Several studies have examined wood functionalization in recent years;however,few studies have reported photochromic TW(PTW)for ultraviolet(UV)-shielding window applications.Herein,PTW was obtained by infiltrating the delignified wood template with photochromic silver bromide(AgBr)nanoparticles and a pre-polymerized methyl methacrylate(MMA)mixture solution.The obtained PTW can adjust the luminous flux on change in the color in the visible light region.The photochromic properties were examined,and the optical properties of the composites were characterized using UV-Vis spectrophotometry.Light transmittance of PTW was up to 86.5%at 800 nm before UV irradiation,and it decreased to 70.1%at 800 nm after UV irradiation,as the wood color changed from colorless to dark purple under UV irradiation.Thus,this work not only achieves high-value utilization of wood,but also produces a new material that can be used in varied fields,such as UV-shielding,energy saving,and smart building.

Modification of Bentonite and Its Application in Antimicrobial Material

This paper aims to expand the application scope of bentonite. The structure of bentonite and the purification and pretreatment methods performed before its modification were reviewed. The modification of bentonite and its application in antibacterial materials were emphasized.