权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Formation Mechanism of Triply Periodic Minimal Surface as a Thermodynamic Equilibrium Structure

热力学平衡结构三周期极小曲面的形成机制

基本信息

批准号：
15350110
负责人：
SAITO Kazuya
金额：
$ 9.92万
依托单位：
University of Tsukuba (2004-2005)Osaka University (2003)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Thermodynamic and structural study was conducted on thermotropic and lyotropic liquid crystals paying special attention on why so complex structures closely related to triply periodic minimal surfaces (TPMS) are spontaneously formed. Smaller heat capacity than neighboring liquid crystalline phases is common to TPMS-related cubic phases both in thermotropic and lyotropic systems. This trend can be understood by considering the suppressed fluctuation due to three-dimensional connectivity of TPMS. The analysis of the phase transition entropy between lamellar (smectic) and cubic phases suggests the possible construction of "thermodynamics" on the basis of "surfaces", where a unit cell of cubic phase would play a role of a basic unit. Appearance of plural cubic phases depending on the alkyl chain length was proved through putting a new example, BABH series. On the basis of the alkyl chain length dependence of the reflection intensities from a cubic phase having Ia3d symmetry (gyroid phase), the aggregation structure at the molecular level was, for the first time, revealed. The ends of alkyl chain of BABH molecules are located on the gyroid while the molecular cores aggregated to form a "jungle gym" consisting of rod-like aggregates. This aggregation mode survives even if the volume of the alkyl chain becomes larger than that of the molecular core. This is in a strong contrast to the cases of block copolymer and lyotropic liquid crystals, where the aggregation mode changes into the inverse phase. In the region where their volumes are roughly equal to each other, the other cubic phase with Im3m symmetry appears commonly in BABH and ANBC. This suggests that the clarification of the molecular aggregation mode in this Im3m phase and of its stability would be a key to solve the issue how different are low-weight thermotropic system from lyotropic system and block copolymers, in both of which physical surface can easily be imagined.

对热致液晶和溶致液晶进行了热力学和结构研究，特别关注为什么会自发形成与三周期极小表面（TPMS）密切相关的复杂结构。在热致和溶致系统中，与 TPMS 相关的立方相都具有比相邻液晶相更小的热容。这一趋势可以通过考虑 TPMS 的三维连接性所抑制的波动来理解。对层状（近晶）相和立方相之间的相变熵的分析表明，基于“表面”的“热力学”的可能构建，其中立方相的晶胞将发挥基本单元的作用。通过新的例子BABH系列，证明了根据烷基链长度会出现多个立方相。基于具有Ia3d对称性的立方相（螺旋相）的反射强度与烷基链长度的依赖性，首次揭示了分子水平的聚集结构。 BABH分子的烷基链末端位于螺旋体上，分子核心聚集在一起，形成由棒状聚集体组成的“丛林健身房”。即使烷基链的体积变得大于分子核心的体积，这种聚集模式仍然存在。这与嵌段共聚物和溶致液晶的情况形成鲜明对比，其中聚集模式变为反相。在它们的体积大致相等的区域中，BABH和ANBC中通常出现具有Im3m对称性的另一个立方相。这表明，阐明Im3m相中的分子聚集模式及其稳定性将是解决低重量热致体系与溶致体系和嵌段共聚物之间有何不同的关键，这两种体系的物理表面都可以很容易想象。

项目成果

期刊论文数量（16）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Y.Maeda, K.Saito, M.Sorai: "Phase Behavior of the Thermotropic Cubic Mesogen 1,2-Bis(4-n octyloxybenzoyl)hydrazine under Pressure"Liq.Cryst.. 30・10. 1139-1149 (2003)

Y.Maeda、K.Saito、M.Sorai：“热致立方介晶 1,2-双(4-n 辛氧基苯甲酰基)肼在压力下的相行为”Liq.Cryst.. 1139-1149 (2003)

DOI：
发表时间：
期刊：
影响因子：
0
作者：
通讯作者：

Alkyl group as entropy reservoir in an MMX chain complex, Pt2(n-PenCS2)4I.

DOI：
10.1021/jp046187o
发表时间：
2005-02
期刊：
The journal of physical chemistry. B
影响因子：
0
作者：
Kazuya Saito;Satoaki Ikeuchi;Y. Nakazawa;A. Sato;M. Mitsumi;T. Yamashita;K. Toriumi;M. Sorai
通讯作者：
Kazuya Saito;Satoaki Ikeuchi;Y. Nakazawa;A. Sato;M. Mitsumi;T. Yamashita;K. Toriumi;M. Sorai

Molecular Dynamics and Residual Entropy in the Soft Crystal, SmE Phase, of 4-Butyl 4'-isothiocyano-1,1'-biphenyl

4-丁基 4-异硫氰基-1,1-联苯软晶体 SmE 相的分子动力学和残余熵