硫在螺旋炭纤维固相催化生长机理中的作用

EFFECT OF SULFUR ELEMENT ON SOLID CATALYTIC GROWTH MECHANISM OF MICRO—COILED CARBON FIBERS

通过电沉积法在石墨基体上电沉积含硫的光亮镍催化剂,采用化学气相沉积法直接生长出螺旋炭纤维,生长温度仅为650℃;螺旋炭纤维的螺旋直径为700nm,炭纤维直径为400nm,纯度高且质量好,螺旋炭纤维中由三股炭纤维相互规则缠绕成绳状结构炭纤维。催化剂不含硫元素时,炭纤维为无规则的弯曲形纤维;催化剂含硫量高时,炭纤维为规则的褶皱形纤维,催化剂硫含量影响炭纤维形貌生长。螺旋炭纤维生长机理为固态催化生长,硫元素通过影响镍催化剂表面的各向异性和内部催化活性来影响炭纤维的形貌生长。

Micro—coiled carbon fibers were directly prepared by chemical vapour deposition on the graphite substrate by using electrodeposition of nickel containing sulfur as catalysts,and growth temperature of micro-coiled carbon fibers was only 650℃. The diameter of coil and micro—coiled carbon fiber with high quality are about 700 nm and 400 nm. respectively. The rope—carbon fibers which are made up of three carbon fibers regularly ,twisted each other in micro—coiled carbon fibers. Products were irregular non—linear carbon fibers using Ni without sulfur as catalysts ;and products were regular flute—carbon fibers using Ni with high content sulfur as catalysts. Morphologies of carbon fibers were influenced by the amount of sulfur in catalysts. Growth mechanism of micro—coiled carbon fibers are solid catalytic growth mechnismand. And morphologies of carbon fibers were affected by sulfur element which influenced anisotropy and catalytic action of Ni catalyst.