Fabrication and Characterisation of Ultra-Fine Powders from Mulberry, Eri and Muga Silk Fibres
This research investigated ways of producing ultra- fine silk particles through mechanical attrition by optimising milling sequence and milling conditions. Apart from mulberry silk, two Indian non mulberry commercial varieties, Eri from Philosamia cynthia ricini silkworm and muga from Antheraea Assama silkworm were included for powder production. Silk cocoons were degummed normally as well as intensively. Chopped degummed and intensively degummed fibres were pulverised through dry or wet planetary ball milling followed by air jet milling. Attritor milling was also performed. Variable shaped particles with volume average particle size below 20μm could be fabricated by ball milling within 12-18hours depending on silk types and milling conditions. Intensive degumming reduced molecular weight of silk fibroin and thereby produced similar particles within 4-8hours. Further processing using air jet mill decreased size to below 10μm with a narrow size distribution. Wet attritor milling was very effective. Volume average particle size less than 300nm could be fabricated within 6hours from normally degummed silk. Axial spitting and fragmentation of micro and nano fibrillar architecture of fibres during size reduction process was observed from SEM images. Mechanical attrition decreased molecular weight as revealed by SDS-PAGE analysis. However, there was no change indicated in β conformation of fibroin molecules as per FTIR results. Overall behaviour of three varieties was similar though attrition time for non mulberry silk fibres was shorter. The significant advancement in producing ultra-fine silk powder materials through the common milling systems should widen the application scope of silk and other organic fibre materials.
mechanical attrition particle size milling silk fibre
Rangam Rajkhowa Lijing Wang Xungai Wang
Centre for Material and Fibre Innovation Deakin University, Geelong, Australia 3217
国际会议
苏州
英文
154-164
2007-09-13（万方平台首次上网日期，不代表论文的发表时间）