Cellulosic nanocomposites with unique morphology and properties

Foam;Electrospinning;Cellulose microfibril;Surface property;Cellulose nanowhisker

Lee, Jihoon ; Chemical Engineering

University:Georgia Institute of Technology

Department:Chemical Engineering

关键词: Foam;    Electrospinning;    Cellulose microfibril;    Surface property;    Cellulose nanowhisker;   

Others  :  https://smartech.gatech.edu/bitstream/1853/37149/1/Lee_Jihoon_201012_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Cellulose nanowhiskers reinforced poly(vinyl alcohol)(PVA) nanofiber web is successfully fabricated using electrospinning technique and the mechanical properties of the single electrospun fiber are measured using nanoindentation method. The morphology and mechanical properties of highly aligned electrospun fiber webs are investigated. It is found that the modulus and tensile strength of aligned webs are higher than those of isotropic electrospun fiber webs. Experimental results are compared with a longitudinal Halpin-Tsai model. Ice-templated(IT) cellulose microfibril porous foams are successfully fabricated via unidirectional freezing methods. The morphology and growth mechanism of IT surfaces are investigated successfully using cellulose microfibrils and hydrophillic substrates. By controlling the temperature gradient between cellulose microfibril suspensions and secondary freezing mediums, various surface structures including honey-comb like structures, ellipse-shape channel strcutures, fully developed multichannel structures are obtained. For the honey-comb like patterned surface, high contact angles are observed. On the other hand, for the layered patterned surface, anisotropic wetting properties are observed.