Abstract-Optical Properties of Tetrahydrofuran Clathrate Hydrates with Polyvinylpyrrolidone (THF + H2O + PVP) Revealed by Terahertz (THz) Time-Domain Spectroscopy

Hyery Kang †, Dong-Yeun Koh †, Yun-Ho Ahn †, Seonghoon Jung §, Jaehun Park §, Jaehyoung Lee*∥, and Huen Lee *†‡

† Department of Chemical and Biomolecular Engineering (BK21+ program), KAIST, Daejeon 305-701, Republic of Korea

‡ Graduate School of EEWS, KAIST, Daejeon 305-701, Republic of Korea

§ Pohang Accelerator Laboratory, POSTECH, Pohang 790-784, Republic of Korea

∥ Petroleum & Marine Research Division, Korea Institute of Geoscience & Mineral Resources, Gwahang-no 92, 30, Yuseong-gu, Daejeon 305-350, Republic of Korea

J. Chem. Eng. Data, Article ASAP

DOI: 10.1021/je5005092

Publication Date (Web): October 29, 2014

Copyright © 2014 American Chemical Society

*(H.L.) E-mail: hlee@kaist.ac.kr., *(J.L.) E-mail: ljh1155@kigam.re.kr

http://pubs.acs.org/doi/abs/10.1021/je5005092

Terahertz time-domain spectroscopy (THz-TDS) was used to observe the tetrahydrofuran (THF) clathrate hydrate system with dosage of polyvinylpyrrolidone (PVP) with three different average molecular weights (10 000 g/mol, 40 000 g/mol, and 360 000 g/mol). Distinct footprints of phase transition in the THz region (0.4 THz to 2.2 THz) were analyzed and absorption coefficients and complex refractive indices are obtained and compared in the temperature range of 253 to 288 K. Along with the optical properties, ring breathing and stretching modes for different molecular weights of PVP in THF hydrate are analyzed by Raman spectroscopy.