Using a relative small amount of reactive mesogenic monomer and a quasi-bookshelf texture of ferroelectric liquid crystals (FLCs) we developed submicron-scale templated polymer fibrils from the two-dimensionally ordered hosts. The polymer fibrils capture the orientation of the host with thin polymer fibrils interweaving the smectic layers that act as additional surfaces for controlling the reorientation of FLC molecules. The SEM study shows the difference in morphology of the polymer fibrils depending on the polymerization conditions and FLC hosts. There are two distinctive electro-optical properties of polymer modified FLC such as the fast switching at a lower applied field and the voltage independence of switching time achieved by polymer stabilization using a mesogenic monomer. Further, we describe how the polymer network and the type of FLC enhance the realization of V-shaped switching behavior.

Photosensitive-fluorescein polyurethane (PU) ionomer was successfully synthesized at our laboratory. The reaction of toluene diisocyanate with polyester, fluorescein, hydroxypropyl acrylate and other major additives to form the Structures of these ionomers has been proven by FT-IR spectroscopy. For a dilute concentration of photosensitive-fluorescein PU ionomer molecule in aqueous solution, the fluorescence studied exhibits fluorescence at around 508 nm, In aqueous Solution, the number average particle size appears to increase with increasing concentration of epoxy, fluorescein and hydroxypropyl acrylate used to prepare the photosensitive-fluorescein PU ionomer molecules. The reason for the free volume of photosensitive-fluorescein PU ionomer molecules is due to strong intermolecular interactions between hydrophilic groups of these ionomer molecules increasing. Therefore, the number average particle sizes of these ionomer molecules increases. Furthermore, the addition of benzoin as a photoinitiator to photosensitive fluorescein PU ionomer molecule results in an increase 1. 5 the average particle size of this ionomer molecule. This is due to increased free volume resulting from strong internzmolecular interaction between hydrophilic groups Of ionomer molecules. For self-cured films made by photosensitive-fluorescein PU iononzer, the tensile Strength is seen to increase with increasing concentration of epoxy, fluorescein and hydroxypropyl acrylate, respectively. This may be attributed to increased crosslinking due to strong intermolecular interaction between photosensitive-fluorescein PU ionomer molecules theinselves. However, the addition of benzoin as a photoinitiator to photosensitive-fluorescein PU ionomers results in an increase in the tensile strength of these ionomers as well. Copyright (C) 2002 John Wiley Sons, Ltd.

The reaction of methylene diphenylene diisocyanate with ethylene glycol, dimethyl dimethoxysilane, dimethyl diethyloxysilene, and other additives in the presence of N,N-dimethylformamide and toluene to form the structure of water-vapor-permeable polyurethane (PU) resin was proven with Fourier transform infrared spectra. Experimental results clearly showed that the amount of oxygen that permeated the film made with the PU resin increased with an increase in the concentration of ethylene glycol, diethylene glycol, or triethylene glycol. This was due to an increased number of hydrophilic groups attached to the backbone of the PU resin molecules. These hydrophilic groups, because of the intermolecular interactions between PU resin molecules, made PU resin molecules form an expanded conformation with large porosities. Interestingly, the water vapor permeability of the PU resin appeared to increase with an increasing concentration of ethylene glycol, dimethyl dimethoxysilane, or dimethyl diethoxysilane but not to increase with an increasing concentration of diethylene glycol, triethylene glycol, or poly(ethylene glycol) with dimethyl dimethoxysilane. The former was due to intermolecular interactions resulting in an expanded conformation with large porosities, but the latter was due to intramolecular interactions resulting in a compact conformation or a micellelike structure with small porosities. Therefore, the water vapor permeability of the former increased, but the latter remained unchanged or decreased. Our experimental results suggest that the use of poly(ethylene glycol) 400, ethylene glycol, dimethyl dimethoxysilane, and other strong hydrophilic Compound in the preparation of modified PU resins substantially raises the amount of water vapor diffusing into films made with these resins. (C) 2002 Wiley Periodicals, Inc.

The use of a fingerprint texture of a cholesteric liquid crystal is demonstrated as a template to direct the formation of periodically ordered micro-size polymer walls. The morphology-property correlation of polymer-stabilized cholesteric gratings (PSCGs) was established for mesogenic and non-mesogenic reactive monomers. These PSCGs are suitable for laser beam steering, control of fibre optic signal and dynamic focus lenses.

We applied ellipsometry to study the distribution of azobenzene fragments in the films of two types of comblike polymers with azobenzene moieties in the side chains before and after ultraviolet (UV) light irradiation. The polymer with an alkyl chain at the end of the azobenzene fragment forms structures with preferred homeotropic alignment of the fragments. Irradiation of this polymer with nonpolarized UV light at normal incidence induces a homeotropic alignment of azobenzene fragments. Oblique irradiation induces tilted structures. Polarized UV light irradiation at normal beam incidence induces biaxial structures with a fanlike distribution of azobenzene fragments and preferably out-of-plane alignment. The polymer with polar nitro group at the end of the azobenzene moiety shows preferential in-plane orientation. The degenerate in-plane alignment is retained for normal irradiation with nonpolarized UV light. Excitation with polarized light provides highly ordered in-plane alignment of the azobenzene fragments perpendicular to the UV light polarization. Re-orientation of the fragments under a second UV exposure with orthogonal polarization involves out-of-plane rotation of the fragments.

We studied the 3D distribution of azobenzene fragments in the films of two comb-like liquid crystalline azopolymers before and after irradiation by actinic UV light using a null ellipsometry technique. The polymer with an alkyl chain C6H13 at the end of the azobenzene fragment forms structures with preferred homeotropic alignment of the fragments. Polarized UV light irradiation at normal beam incidence induces biaxial structures with a preference for out-of-plane alignment of azobenzene fragments. High UV doses induce highly ordered homeotropic alignment of the fragments. The second polymer with polar NO2 group at the end of the azobenzene moiety shows preferential in-plane orientation. Excitation with polarized light provides a highly ordered in-plane alignment of the azobenzene fragments perpendicular to the UV light polarization.

Several alkenyl diphenyldiacetylene liquid crystals were synthesized and their physical properties evaluated. The introduction of a double bond in the side chain leads to an unexpectedly wide nematic range and an extraordinarily large figure of merit at elevated temperatures. These liquid crystals are particularly attractive for infrared laser-beam steering.

Ring contraction and rearrangement of 4-thiofuranose derivatives were observed through the regioselective opening of the episulfonium ion formed during DAST fluorination in the synthesis of l-2′-“up”-fluoro-4′-thiothymidine.

We report the use of a low concentration polymer network to stabilize electric field-induced diffraction gratings in cholesteric liquid crystals. The stabilized gratings can be electrically switched between a zero-field “on” state, which exhibits approximately 75% diffraction efficiency, and a moderate field (typically 3 V/μm) “off” state. Grating spacings between 1.7 and 30 μm are obtained in a 10 μm thick cell by variation of the concentration of chiral dopant used to form the cholesteric liquid crystal.

Journal Article Accuracy and reproducibility of syringe measurements Get access S. Nicole Lee, Pharm.D., S. Nicole Lee, Pharm.D. Research Fellow Department of Pharmacy, Sunnybrook Health Science Centre (SHSC), North York. Ontario, Canada Search for other works by this author on: Oxford Academic Google Scholar Angelina H. Wong, Angelina H. Wong pharmacy student Faculty of Pharmacy, University of Toronto. Ontario; at the time of this study she was a summer student, Department of Pharmacy, SHSC Search for other works by this author on: Oxford Academic Google Scholar Alexandra Mayer, Alexandra Mayer pharmacy student Pharmazeutisches Institut. Universität Tübingen, Tübingen, Germany; at the time of this study she was a summer student. Department of Pharmacy. SHSC Search for other works by this author on: Oxford Academic Google Scholar Scott E. Walker, M.S. Scott E. Walker, M.S. Research Coordinator Department of Pharmacy, SHSC. and Associate Professor, Faculty of Pharmacy, University of Toronto Address reprint requests to Mr. Walker at the Department of Pharmacy, Sunnybrook Health Science Centre, 2075 Bayview .Avenue KB33.3, North York, Ontario, Nf4N 3M5 Canada. Search for other works by this author on: Oxford Academic Google Scholar American Journal of Health-System Pharmacy, Volume 53, Issue 10, 15 May 1996, Pages 1166–1169, https://doi.org/10.1093/ajhp/53.10.1166 Published: 15 May 1996

Clinical Pharmacology & Therapeutics (1996) 59, 162–162; doi:10.1038/sj.clpt.1996.149

Equipment base isolation can protect mechanics and valuable antiques from seismic hazard. The rolling type base isolation is developed for this purpose and was verified by shaking table tests in NCREE. It can reduce more than 80% acceleration response during earthquake. The rolling type base isolation has no impact on the total function of computer servers during assembling. Several rolling base isolations can form a large isolated platform and can be applied to different seismic protection requirements.