نتایج جستجو برای: mesophase

تعداد نتایج: 751  

2006
Wesley P. Hoffman

In this work, we examined the microstructures formed during the pyrolysis of naphthalene mixed with AlCl3 catalyst, in the crit-ical temperature range of 300–500 C and at varying pressures. In addition, non-rigidized preforms were densified by multiple cycle in situ transformation and compared the process with impregnation using fully transformed AR mesophase pitch under similar conditions....

Journal: :Journal of pharmaceutical sciences 2006
Akira Terakita Stephen R Byrn

The aim of this study is to investigate the hydration and the dehydration processes of calcium benzoate hydrates (trihydrate and monohydrate), thermotropic mesophases (dehydrated mesophase and lyophilized mesophase) and amorphous state, and the influence of their molecular order on those processes. X-ray analysis revealed that trihydrate has a planar structure composed of two types of planes-on...

Journal: :Journal of the American Chemical Society 2004
Limin Liu Mohit Singh Vijay T John Gary L McPherson Jibao He Vivek Agarwal Arijit Bose

Highly aligned stringlike silica nanostructures are obtained through templated synthesis in the columnar hexagonal structure of a rigid crystalline surfactant mesophase. A two-step procedure is used to first shear-align the surfactant mesophase and then conduct synthesis under quiescent conditions in the mesophase. The mesophase retains its alignment for extended periods, allowing materials syn...

2004
Cheng-Yang Wang

Mesophase spheres were prepared through homogeneous and heterogeneous nucleation from two coal tar pitches with some and nearly without quinoline insolubles. The pitches suffered thermal condensation in a stainless steel reactor at 440 and 410 for 1 or 7h, respectively. SEM was introduced as a useful tool to detect the structures of the two kinds of mesophase spheres. As a result of the paper, ...

2001
Hongbin Li Xi Zhang Ruifeng Zhang Jiacong Shen Bing Zhao Weiqing Xu

The thermotropic liquid crystalline behavior of a new kind of amphiphilic polymer without mesogens is reported. The existence and structure for the polymeric mesophase are confirmed and characterized by DSC, X-ray diffraction, optical polarized microscopy, and temperature-dependent FTIR. Due to strong interactions between pendent long alkyl chains, we conclude that some hydrophobic semirigid ro...

Journal: :Chemical communications 2004
Andreas Taubert Ernst Furrer Wolfgang Meier

A water-in-water mesophase that contains only hydrophilic domains is reported for the first time; the mesophase templates highly porous calcium phosphate.

Journal: :Dalton transactions 2011
Hai-Bao Duan Xiao-Ming Ren Lin-Jiang Shen Wan-Qin Jin Qing-Jin Meng Zheng-Fang Tian Shi-Ming Zhou

A low-dimensional compound [C(6)-Apy][Ni(mnt)(2)] (1, where mnt(2-) = maleonitriledithiolate, C(6)-Apy(+) = 4-amino-1-hexylpyridinium) has been designed and synthesized, which has layer arrangement of anions and cations and shows two steps of magnetic transitions. The low temperature magnetic transition has an uncommon hysteresis loop, while the crystal structure investigations disclosed no str...

2015
Ming Li Dong Liu Hui Du Qinyin Li Xulian Hou Jiashun Ye

Two aromatics-rich distillates R1 and R2 with different properties from naphthenic base vacuum gas oil were used for preparing mesophase pitch through high-pressure thermal treatment. 1H-NMR, FT-IR and VPO were employed to characterize the structural parameters of the raw materials. The products' optical texture and molecular structure were analyzed by polarized light optical microscopy, 1H-NMR...

Journal: :Sen'i Gakkaishi 1979

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