1. a School of Nano and Advanced Materials Engineering , Gyeongsang National University , Gyeongnam, Jinju, South Korea
2. b School of Material Science and Engineering , Shandong University , Jinan, China
3. e Key Laboratory of Rubber-Plastics, Ministry of Education, Shandeng Provincial Key Laboratory of Rubber-Plastics , Qingdao University of Science and Technology , Qingdao, China
4. c Pyung Hwa Industrial Co. Ltd. , Daegu City, South Korea
5. d Hyundai Kia Motors Co. Ltd. , Seoul, South Korea