1. National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu 610065, P.R. China
2. College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P.R. China
3. Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, P.R. China