纤维素气凝胶、甲基纤维素气凝胶和纤维素-SiO_(2)复合气凝胶的CCl_(4)冷等离子体疏水改性

The CCl cold plasma hydrophobic modification of cellulose aerogel,MC cellulose aerogel and cellulose-SiO_(2) composite aerogel

纤维素气凝胶材料的亲水性使其易吸收水和空气中的水蒸汽,从而降低了材料的性能,因此对纤维素气凝胶材料的表面疏水改性具有重要意义。在相似的水环境下,通过物理交联的方法,制备了纤维素气凝胶与甲基纤维素(MC)气凝胶。纤维素气凝胶在NaOH硫脲/H_(2)O溶液体系中获得,MC气凝胶在NaCl和CaCl_(2)溶液获得。而纤维素-SiO_(2)复合气凝胶采用浸渍法制备。用CCl_(4)作为冷等离子体进行疏水改性,并对上述3种气凝胶的疏水性能进行了讨论。结果显示,MC气凝胶的疏水性比纤维素气凝胶好;同时,SiO_(2)与纤维素复合后,可以降低纤维素气凝胶的亲水性。在进行疏水改性后,它们的表面疏水性显著提高,纤维素气凝胶、MC气凝胶和纤维素-SiO_(2)复合气凝胶与水的接触角分别为102°、110°和132°。复合纤维素的结构特征使得其疏水性的增加。该工作为疏水改性及纤维素气凝胶的应用扩展提供了基础。

Cellulose aerogel materials are hydrophilic and easy to absorb water and vapor in the air,which reduces the properties of the materials.Therefore,the surface hydrophobic modification of cellulose aerogel materials is of great significance.Cellulose aerogel and methyl cellulose(MC)aerogel were prepared by using physical crosslinking method in the similar water condition.Cellulose hygrogel was obtained with the NaOH/thiourea/H_(2)O solvent system.MC hydrogel was obtained in NaCl and CaCl_(2)aqueous solution.The immersion method was adopted to prepare cellulose-SiO_(2)composite hydrogel.These hydrophobic aerogels were prepared through the freeze-drying technology and the cold plasma modification technology with CCl_(4)as plasma.The hydrophobic properties of three kinds of aerogels were discussed.The results showed that the hydrophobicity of MC aerogel was better than of cellulose aerogel,composited SiO_(2)could reduce the hydrophilicity of cellulose aerogel.After hydrophobic modification was conducted,their surface hydrophobicity was significantly improved and water contact angle was 102°,110°and 132°.The structure characteristic of composite aerogel led to an increase in hydrophobicity.This work provided a foundation for the hydrophobicity modification and a certification to extend the application scopes of different cellulose aerogels.