Earticle

초록

영어

Deuterium NMR studies have been carried out for two kinds of main- chain dimer liquid crystals .-bis[(4,4`-cyanobipheny0oxy] alkane (CBA-n, n=9,100.The H-NMR spectra were recorded on a JEOP JNM-GSX-500 spectrometer by using deuterium labelled CBA-n at various temperatures. The RIS analysis of the NMR spectra was performed so as to elucidate the conformational characteristics of the spacer in the nematic phase. Following the previous treatment, the single-ordering-matrix model was adopted, in which the molecular axis was defined parallel to the line connecting the centers of the terminal mesogenic cores. Conformer fractions of the spacer were estimated by simulation so as to reproduce the observed NMR profile. The conformational entropy changes at both CN and NI interphases were estimated on the basis of the nematic conformations taken from the conformation map as well as those derived from the simulation. In these calculations the spacer was assumed th by in the all-trans conformation and in the random coil stats in the crystal and isotropic phases respectively. The esimated conformational entropy change values were then compared with the corresponding constant-volume entropies obtained from PVT measurements. The correspondence between both entropy values was found to be quite good in consideration of the uncertainties involved in both experiment and calculations.

목차

Abstract
 I. 서론
 II. 실험
 III. 결과 및 고찰
 IV. 결론
 참고문헌

저자

• 김정곤 [ Jeong-Kon, Kim | 부경대학교 고분자공학과 ]
• 박찬영 [ Chan-Young, Park | 부경대학교 고분자공학과 ]
• 민성기 [ Seong-Kee, Min | 부경대학교 고분자공학과 ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국인쇄학회지 [JOURNAL OF THE KOREAN GRAPHIC ARTS COMMUNICATION SOCIETY]

• 간기

  연간

• pISSN

  1226-1149

• 수록기간

  1983~2025

• 십진분류

  KDC 586 DDC 686