title: Thermo-responsive and compression properties of TEMPO-oxidized cellulose nanofiber-modified PNIPAm hydrogels.
abstract: In this study, TEMPO-oxidized bamboo cellulose nanofibers (TO-CNF) with anionic carboxylate groups on the surfaces were in-situ incorporated into poly(N-isopropylacrylamide) (PNIPAm) matrix to improve its thermo-responsive and mechanical properties during the polymerization. The microstructure, swelling behaviors, and compressive strength of resultant PNIPAm composite hydrogels with varying contents of TO-CNFs (0-10wt%) were then examined, respectively. Modified hydrogels exhibited the similar light transparency to pure PNIPAm one due to the formation of semi-IPN structure between PNIPAm and TO-CNF. FT-IR spectra demonstrated that the presence of TO-CNF did not alter the position of characteristic peaks associated with PNIPAm. SEM observation suggested that the pore size of PNIPAm hydrogels was markedly increased after the incorporation of TO-CNF. Also, the composite hydrogels showed superior swelling behavior and much improved compression properties with respect to pure PNIPAm one. Thus, TO-CNF appeared to be a "green" nanofiller that can simultaneously improve swelling and mechanical properties of PNIPAm hydrogel.
authors.affiliation: School of Engineering, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang Province 31130, PR China.
authors.forename: Jinguang
authors.initials: J
authors.lastname: Wei
authors.affiliation: School of Engineering, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang Province 31130, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Engineering, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang Province 31130, PR China; National Engineering and Technology Research Center of Wood-based Resources Comprehensive Utilization, Lin'an, Hangzhou, Zhejiang Province 311300, PR China. Electronic address: hzliu@iccas.ac.cn.
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Engineering, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang Province 31130, PR China; National Engineering and Technology Research Center of Wood-based Resources Comprehensive Utilization, Lin'an, Hangzhou, Zhejiang Province 311300, PR China. Electronic address: chunguidu@163.com.
authors.forename: Chungui
authors.initials: C
authors.lastname: Du
authors.affiliation: School of Engineering, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang Province 31130, PR China.
authors.forename: Huilong
authors.initials: H
authors.lastname: Yu
authors.affiliation: School of Engineering, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, Zhejiang Province 31130, PR China.
authors.forename: Zhongxi
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002483:Cellulose, Oxidized / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013696:Temperature
chemical_list: D000180:Acrylic Resins; D002483:Cellulose, Oxidized; D003497:Cyclic N-Oxides; D020100:Hydrogels; C052970:poly-N-isopropylacrylamide; C003959:TEMPO
keywords: (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (PubChem CID:2724126); Cellulose nanofibers; Compression properties; Morphology; N,N'-methylenebisacrylamide (PubChem CID: 8041); N,N,N',N'-tetramethyl-ethane-1,2-diamine (PubChem CID: 8037); N-isopropyl acrylamide (PubChem CID: 16637); Poly(N-isopropylacrylamide); Potassium persulfate (PubChem CID:24412); Sodium bromide (PubChem CID: 253881); Sodium hypochlorite (PubChem CID: 23665760); Swelling behaviors