Surface Modification of Graphite Whisker for Composite Materials by Plasma

本计画旨在应用电浆聚合及电浆处理技术于石墨晶须之亲水性表面改性。研究结果如下：1.暴露于含氧或含氮化合物的等离子体导致亲水表面。2.硝基化合物如硝基甲烷是制备亲水性等离子体聚合物的合适起始材料。NO和NO_2等氮氧化物是等离子体处理亲水表面的合适气体。3.通过等离子体处理引入到表面上的有助于亲水性的官能团是羟基、羰基和羧基。4.在表面上产生的官能团的浓度与被处理表面的亲水性密切相关。5. NO-和NO_2-等离子体氧化石墨晶须表面，使其亲水化。6.通过NO等离子体处理，在石墨晶须表面引入了羰基和羧基，其浓度约为热HNO_3处理的5倍。因此，NO或NO_2等离子体处理是一种独特的石墨晶须亲水改性技术。

The objective in this project is the application of plasma polymerization and plasma treatment for hydrophilic surface modification of graphite whiskers. The results are summarized as follows.1. The exposure to plasma of oxygen- or nitrogen-containing compounds leads to hydrophilic surfaces. 2. Nitro compounds such as nitromethane are suitable starting materials for preparation of hydrophilic plasma polymers. Nitrogen oxides such as NO and NO_2 are suitable gases for hydrophilic surface modification by means of plasma treatment. 3. The functional groups introduced onto surfaces by the plasma treatment, which contribute to hydrophilicity, are hydroxyl, carbonyl, and carboxyl groups. 4. The concentration of the functional groups generated onto the surface is closely related to the hydrophilicity of the treated surface. 5. The NO- and NO_2-plasma oxidize the surface of graphite whiskers and make them hydrophilic. 6. Carbonyl and carboxyl groups are introduced onto the whisker surfaces by NO-plasma exposure, and their concentration is about five times more than that of the graphite treated with hot HNO_3.In conclusion, the NO- or NO_2-plasma treatment is a distinguished technique for hydrophilic modification of graphite whisker.