1. Key Laboratory for Colloid and Interface Chemistry of the Education Ministry, Shandong University, Jinan, Shandong 250100, P. R. China
2. Department of Oil and Gas Storage and Transportation Engineering, China University of Petroleum, Qingdao, Shandong 266555, P. R. China
3. Department of Chemistry, Shandong Institute of Education, Jinan, Shandong 250013, P. R. China