Liquid crystals (Print)最新文献_第9页

Ferroelectric liquid crystal mixtures containing chiral ether and ester compounds with the 2-arylidene-p-menthan-3-one skeleton 含有手性醚和具有2-芳基烯-比3- 1骨架的酯类化合物的铁电液晶混合物

Liquid crystals (Print) Pub Date : 2002-06-27 DOI: 10.1117/12.472142

E. Popova, Lidiya A. Kutulya, V. Vashchenko, M. Pivnenko, A. I. Krivoshey, A. P. Fedoryako

{"title":"Ferroelectric liquid crystal mixtures containing chiral ether and ester compounds with the 2-arylidene-p-menthan-3-one skeleton","authors":"E. Popova, Lidiya A. Kutulya, V. Vashchenko, M. Pivnenko, A. I. Krivoshey, A. P. Fedoryako","doi":"10.1117/12.472142","DOIUrl":"https://doi.org/10.1117/12.472142","url":null,"abstract":"Some1R,4R-2-(4-phenylbenzylidene)-p-methane-3-one derivatives containing the ether or ester linking group between benzene rings of the arylidene fragment have been studied as chiral dopants in ferroelectric liquid crystal systems based on the eutectic mixture (1:1) of two phenylbenzoate derivatives (see paper for formula) The ferroelectric properties of these compositions (spontaneous polarization, rotation, viscosity, smectic tilt angle as well as quantitative characteristics of their concentration dependences) were compared with those for systems including chiral dopants containing no linking group. Ferroelectric parameters of the induced ferroelectric compositions studied have been shown to depend essentially on the presence of the linking group between benzene rings and its nature as well as on the number of the benzene rings in the rigid molecular core of the chiral dopants used. For all ferroelectric liquid crystal systems studied, the influence of the chiral dopants on the thermal stability of N*, SmA and SmC* mesophases has been quantified. The influence of the linking group nature in the dopant molecules on the characteristics of the systems studied is discussed taking into account results of the conformational analysis carried out by the semi-empirical AM1 and PM3 methods.","PeriodicalId":132866,"journal":{"name":"Liquid crystals (Print)","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123552436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Mesomorphism and photocuring processes of (2-hydroxypropyl) cellulose cinnamate 肉桂酸(2-羟丙基)纤维素的介形与光固化过程

Liquid crystals (Print) Pub Date : 2002-06-27 DOI: 10.1117/12.472155

P. Wojciechowski, L. Okrasa, M. Kozanecki

{"title":"Mesomorphism and photocuring processes of (2-hydroxypropyl) cellulose cinnamate","authors":"P. Wojciechowski, L. Okrasa, M. Kozanecki","doi":"10.1117/12.472155","DOIUrl":"https://doi.org/10.1117/12.472155","url":null,"abstract":"Mesomorphism and photocuring processes of (2- hydroxypropyl)cellulose cinnamate (CYPC) were investigated. The CYPC was synthesized in the course of estrification of (2-hydroxypropyl)cellulose (HPC) by cinnamoyl chloride. The chemical structure of CYPC was confirmed by IR and Raman spectroscopy. The substitution degree of HPC by cinnamoyl ester groups was calculated from 1H-NMR studies. The thermotropic mesomorphism of CYPC was confirmed by DSC, thermo-optical and X-ray investigations. The thermo-optical behaviors of CYPC tablet obtained under pressure and results of the dielectric spectroscopy investigations were interpreted in terms of the strong hydrophobic effect of the cinnamoyl ester groups. The cycloaddition of the cinnamoyl groups is initiated either by UV radiation or temperature, inside of the hydrophobic aggregates of the cinnamoyl ester groups. The chemical modification of the hydrophobic aggregates in the course of thermo- or photoaddition of the cinnamoyl ester groups slightly changes a molecular movement of the poly(saccharide) main chains of CYPC. However, these crossed aggregates can recover macromolecular orientation of CYPC from the isotropic state via the cooling of sample. These suggest that the hydrophobic aggregates after thermal or photochemical modification shows an anisotropic behavior.","PeriodicalId":132866,"journal":{"name":"Liquid crystals (Print)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126364835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Tuned liquid crystalline interferometer analysis by means of generalized Berreman matrix 用广义Berreman矩阵分析调谐液晶干涉仪

Liquid crystals (Print) Pub Date : 2002-06-27 DOI: 10.1117/12.472180

A. Walczak, E. Nowinowski-Kruszelnicki, L. Jaroszewicz, P. Marciniak

引用次数: 4

Thermochromic liquid crystals in heat transfer research 热致变色液晶在传热研究中的应用

Liquid crystals (Print) Pub Date : 2002-06-27 DOI: 10.1117/12.472179

J. Stasiek, T. Kowalewski

引用次数: 15

Diffraction efficiency in dye-doped LC cells under low-frequency AC voltage 低频交流电压下染料掺杂LC电池的衍射效率

Liquid crystals (Print) Pub Date : 2002-06-27 DOI: 10.1117/12.472164

T. Grudniewski, J. Parka, R. Dabrowski, A. Januszko, A. Miniewicz