摘要:

Liquid crystals can be trapped into inorganic (silica) substrates by sol-gel processes. The sol-gel process consists of hydrolysis and polycondensation reactions of metal organic monomers, i.e. organoalkoxy silanes, which allows the formation of a silica gel-glass. These processes have been used since 1984 for trapping organic molecules into inorganic oxides; usually, single molecules are trapped into isolated gel-glass (nm size) pores. However, it is possible, by chemical means, to induce larger (0.1–10 pm) cavities in the network of the gel-glass allowing the formation of embedded micron size droplets of low molecular weight nematic LC molecules. Surface variations in these cavities (e.g., providing a molecular oriented surface using Si-CH,CH, groups on the pore cage) may allow a lamellar structure and alignment of the nematogenic LC compounds at the surface. It was suggested that order arises as a consequence of the chemical affinity between the apolar character of the pore surface and the lipophilic groups of the LC. Therefore, the main concern has been to ascertain whether the sample manufacturing keeps the LC structure, thus giving gel-glass dispersed liquid crystals (GDLCs) with electrooptical response.

ISSN:1358-314X    

DOI:10.1080/13583149508047619

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The ultra-modern ACT City Complex of Hamamatsu was this year's venue for Asia Display' 95. Formerly known as Japan Display, the renaming of the series of International Display Research Conferences recognizes the growth of the display industry in Asia, and the increasing importance of the region to the world economy. More than 40 per cent of a total of over 200 talks and poster presentations were specifically concerned with liquid crystal displays (LCDs), and following the Conference were whole day workshops on Advanced LCDs and LCD colour filters. Without being biased it is fair to say that LCDs dominated the Conference, although advances in multicoloured Electroluminescent Displays, large area Plasma Displays and Field Emission Displays showed that the LC Display Industry cannot afford to be complacent about rival technologies.

ISSN:1358-314X    

DOI:10.1080/13583149508047620

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

An aim of chemists in recent years has been to develop synthetic routes for the preparation of thermotropic, calamitic metallomesogens with high coordination numbers. Bruce and his colleagues (Adv. Mater. 1995, 7, 665) have now reported a methodology for the synthesis of mesogenic complexes formed by the coordination of the [ReBr(CO)] fragment to 1,4-diaza-1,3-butadienes, 1. The parent ligands exhibit smectic C and nematic phases while the octahedral complexes are exclusively nematogenic. The destruction of smectic behaviour on complexation is attributed to the bulky [ReBr(CO)] fragment disrupting molecular packing. The nematic-isotropic transition temperatures of the complexes are higher than those of the parent ligands. The authors speculate that this surprising observation may be related to a decrease in the flexibility of the ‒N˭CH‒CH˭N‒ segment of the ligand on complexation. It is anticipated that diazabutadienes will become an important synthetic building block for the preparation of new metallomesogens incorporating high coordination number centres.

ISSN:1358-314X    

DOI:10.1080/13583149508047621

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We describe simple classroom experiments that can model the nematic phase, the first order nematicisotropic phase transition, and the effect external stimuli, such as surface treatment, have on the phase transition. These experiments are suitable for the high school level but can be easily adapted to fit the middle school mathematics and science curriculum. With even more simplification, it can also be used to fit the elementary level to qualitatively demonstrate the total loss of order as a liquid crystal melts into a liquid.

ISSN:1358-314X    

DOI:10.1080/13583149508047622

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1358-314X    

DOI:10.1080/13583149508047623

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

ISSN:1358-314X    

DOI:10.1080/13583149508047624

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The Planning and Steering Committee of the ILCS instituted a prize in honour of Professor Glenn Brown for an outstanding PhD thesis in the field of liquid crystal research. In 1992 the International Liquid Crystal Society decided to allow two prizes to be awarded in different areas of liquid crystal science. The laureates are selected prior to each conference in the biennial series of International Liquid Crystal Conferences and will deliver the Glenn Brown Lectures at the Conference.

ISSN:1358-314X    

DOI:10.1080/13583149508047626

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The Westminster Hotel at Le Touquet (France) hosted the Vlth Topical Meeting on Optics of Liquid Crystals from Sunday 24 to Friday 29 September. This series of international conferences gathers, every other year, the specialists in the field. For this meeting and with the agreement of the scientific committee, a double goal was set: first to allow a maximum of young researchers to attend the meeting, and second to widen the audience and the topics covered. It seems that this double goal was achieved. There were 88 delegates, an increase over previous conferences, and amongst them, more than a third were ‘new’ to the field. A greater diversity of countries were represented besides the usual ones (EU, CEE, and some Eastern European countries) delegates were attracted from Brazil, Japan, Korea and Mexico.

ISSN:1358-314X    

DOI:10.1080/13583149508047627

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:1358-314X    

DOI:10.1080/13583149508047618

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor