Liquid crystals (Print)最新文献_第3页

Time-of-flight small angle neutron scattering study of the nematic phase in PAA 向列相在PAA中的飞行时间小角中子散射研究

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581122

A. Rajewska, J. Milczarek

引用次数: 0

Photo-induced phenomena in fullerene-doped PDLC 掺富勒烯PDLC的光致现象

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581215

N. Kamanina

引用次数: 0

Effect of ionic charge on flexoelectric deformations in planar nematic layers 离子电荷对平面向列层挠曲电变形的影响

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581133

M. Felczak, G. Derfel

{"title":"Effect of ionic charge on flexoelectric deformations in planar nematic layers","authors":"M. Felczak, G. Derfel","doi":"10.1117/12.581133","DOIUrl":"https://doi.org/10.1117/12.581133","url":null,"abstract":"Elastic deformations of nematic liquid crystal layers subjected to d.c. electric field were studied numerically. Nearly planar alignment with 1° tilt angle and with finite surface anchoring strength was assumed. The flexoelectric properties of the nematic material as well as the ionic space charge were taken into account. Perfectly blocking electrodes were adopted. The director orientation, the electric potential distribution and the space charge density were calculated. The optical transmission of the layer placed between crossed polarizers was also determined. The deformations had nearly threshold character due to the low value of the surface tilt. It was found that the threshold voltage strongly depended on the parameters of the system. When the nematic was not flexoelectric, the value of the threshold voltage was independent of the ion concentration and was equal to about 1 volt. In the case of a flexoelectric nematic, the threshold as low as a few tenths of a volt occurred when the ion concentration was sufficiently high, and given sufficiently large magnitudes of the flexoelectric coefficients. These results can be explained as the effect of the inhomogeneous electric field arising in vicinity of the surfaces created by the ionic space charge redistributed by the external voltage.","PeriodicalId":132866,"journal":{"name":"Liquid crystals (Print)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126998777","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: 2

The water structure in the polymer network with LC-organisation 具有lc -组织的聚合物网络中的水结构

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581220

A. Joachimiak, P. Wojciechowski, T. Halamus

{"title":"The water structure in the polymer network with LC-organisation","authors":"A. Joachimiak, P. Wojciechowski, T. Halamus","doi":"10.1117/12.581220","DOIUrl":"https://doi.org/10.1117/12.581220","url":null,"abstract":"The water structure existing in (2-hydroxypropyl)cellulose-poly(acrylic acid)-water (HPC-PAA-H2O) hydrogel, exhibiting liquid crystalline (LC) organization of the polymer network (anisotropic hydrogel), was assessed by means of Raman spectroscopy. It was shown that the LC-network of HPC-PAA-H20 exerts significant influence on the structure of liquid water present in the hydration shells around polymer chains of the anisotropic hydrogel. Due to poor stability of LC-ordering of polymer network, observed in HPC-PAA-H2O) after its long-term water immersion, the process of crosslinking of the anisotropic hydrogel was considered. The results of Raman measurements revealed that, during immersion of HPC-PAA-H2O in calcium ions (Ca2+) solution, formation of a salt by poly(acrylic acid) of HPC-PAA-H2O and Ca2+ takes place. This results in crosslinking of the anisotropic hydrogel, leading -- in a consequence -- to significant improvement of its mechanical toughness, as well as to stability of LC-ordering of the investigated network in the swollen state. However, during crosslinking of the anisotropic hydrogel (by Ca2+), apart from formation of the salt by Ca2+ and PAA, the ions influence additionally the structure of the water existing in hydration shells round polymer chains of both polymer constituents (HPC and PAA) creating the anisotropic hydrogel network.","PeriodicalId":132866,"journal":{"name":"Liquid crystals (Print)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128214163","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: 0

Novel addressing scheme for passive antiferroelectric liquid crystal displays 一种新的无源反铁电液晶显示器寻址方案

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581124

X. Quintana, P. Castillo, J. Otón, N. Bennis, A. Lara, V. Urruchi, R. Dabrowski

引用次数: 12

Optical microscopy, DSC, and X-ray diffraction studies on octyl and decyl members of the homologous series 4(4'-n-alkoxybenzoyloxy)phenyl azo-4"-isoamyloxy benzene 光学显微镜、DSC和x射线衍射研究了同源系列4(4′-n-烷氧苯甲氧基)苯基偶氮-4′-异淀粉基苯的辛基和癸基成员

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581102

S. Biswas, P. Mandal, P. Patel, J. S. Dave

{"title":"Optical microscopy, DSC, and X-ray diffraction studies on octyl and decyl members of the homologous series 4(4'-n-alkoxybenzoyloxy)phenyl azo-4\"-isoamyloxy benzene","authors":"S. Biswas, P. Mandal, P. Patel, J. S. Dave","doi":"10.1117/12.581102","DOIUrl":"https://doi.org/10.1117/12.581102","url":null,"abstract":"Octyl and decyl members of the homologous series 4(4'-n-Alkoxybenzoyloxy)phenyl azo-4\"-isoamyloxy benzene have been studied by optical microscopy, DSC and X-ray diffraction techniques. Transition temperatures of the compounds are determined by observing texture by a polarizing microscope while transition enthalpies and entropies are determined by DSC studies. X-ray diffraction photographs of magnetically aligned samples indicate that the octyl member has cybotactic nematic phase while decyl member has cybotactic nematic and monotropic smectic A phase. X-ray photographs are analyzed to calculate intermolecular distance, apparent molecular length in nematics, layer spacing in smectics and orientational order parameters ( and ). Temperature dependence of these parameters has been discussed. Values of and are found to be consistent with Maier-Soupe theoretical values. Lengths of the molecules (L) in most extended conformation are found to be greater than the apparent molecular lengths in nematic phase which suggest that the molecules are tilted in the plane of cybotactic groups. Calculated tilt angles are found to be in between 41.8° to 43.3°.","PeriodicalId":132866,"journal":{"name":"Liquid crystals (Print)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128455234","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: 0

Surface free energy of chosen polyimides and anchoring energy of 6CHBT on these surfaces 所选聚酰亚胺的表面自由能和6CHBT在这些表面上的锚定能

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581211

Jerzy Borycki, M. Wilczek, J. Kędzierski, M. Kojdecki

引用次数: 2

Influence of length of alkyl terminal chain on mesomorphic properties of new chiral liquid crystalline homologous series of thiobenzoates 烷基端链长度对新型手性巯基苯甲酸酯同源系列液晶介形性质的影响

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581074

M. Ossowska-Chruściel, J. Chruściel, S. Zalewski, A. Rudzki, A. Filiks, J. Przedmojski

引用次数: 3

Multicanonical Markov chain Monte Carlo simulation of nematic-isotropic phase transition in liquid crystals 液晶中向列-各向同性相变的多谐马尔可夫链蒙特卡罗模拟

Liquid crystals (Print) Pub Date : 2004-09-01 DOI: 10.1117/12.581100

A. Chakravarthy, K. Venu, V. Sastry, K. Murthy