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Successful Preparation (successful + preparation)
Selected AbstractsSynthesis of TiSe2 Nanotubes/Nanowires,ADVANCED MATERIALS, Issue 16 2003J. Chen The family of layered metal dichalcogenide nanomaterials has been enlarged with the successful preparation of TiSe2 nanotubes/ nanowires (see Figure). A solid-phase reaction is described and the characterization of the product,by X-ray diffraction, scanning and transmission electron microscopy, and Raman measurements,detailed. [source] One-pot synthesis of surface-functionalized molecularly imprinted polymer microspheres by iniferter-induced "living" radical precipitation polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2010Junyi Li Abstract This article describes for the first time the development of a new polymerization technique by introducing iniferter-induced "living" radical polymerization mechanism into precipitation polymerization and its application in the molecular imprinting field. The resulting iniferter-induced "living" radical precipitation polymerization (ILRPP) has proven to be an effective approach for generating not only narrow disperse poly(ethylene glycol dimethacrylate) microspheres but also molecularly imprinted polymer (MIP) microspheres with obvious molecular imprinting effects towards the template (a herbicide 2,4-dichlorophenoxyacetic acid (2,4-D)), rather fast template rebinding kinetics, and appreciable selectivity over structurally related compounds. The binding association constant Ka and apparent maximum number Nmax for the high-affinity sites of the 2,4-D imprinted polymer were determined by Scatchard analysis and found to be 1.18 × 104 M,1 and 4.37 ,mol/g, respectively. In addition, the general applicability of ILRPP in molecular imprinting was also confirmed by the successful preparation of MIP microspheres with another template (2-chloromandelic acid). In particular, the living nature of ILRPP makes it highly useful for the facile one-pot synthesis of functional polymer/MIP microspheres with surface-bound iniferter groups, which allows their direct controlled surface modification via surface-initiated iniferter polymerization and is thus of great potential in preparing advanced polymer/MIP materials. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3217,3228, 2010 [source] PS/PMMA mixed polymer brushes on the surface of clay layers: Preparation and application in polymer blendsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2007Jian Zhang Abstract Polystyrene (PS) and poly(methyl methacrylate) (PMMA) mixed polymer brushes on the surface of clay layers were prepared by using in situ free radical polymerization. Free radical initiator molecules with two quaternary ammonium groups at both ends were intercalated into the interlayer spacing of clay layers. The amount of polymer brushes grafted on the surface of clay layers can be controlled by controlling the polymerization time. Thermogravimetric analysis, X-ray diffraction, and high-resolution transmission electron microscope results indicated successful preparation of the mixed polymer brushes on the surface of clay layers. The kinetics of the grafting of the monomers was also studied. The mixed polymer brushes on the surface of clay layers were used as compatibilizers in blends of PS and PMMA. In the blends, the intercalated clay particles tend to locate at the interface of two phases reducing the interfacial tension. In the meanwhile, PMMA homopolymer chains tend to intercalate into clay layers. The driving force for the intercalation is the compatibility between homo-PMMA chains and PMMA brushes on the surface of clay layers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5329,5338, 2007 [source] 4241: Optical characterization of PCOACTA OPHTHALMOLOGICA, Issue 2010TJTP VAN DEN BERG Purpose Opacification of the posterior capsule (PCO) is known to degrade visual function on both counts: small angle resolution (visual acuity and contrast sensitivity) as well as large angle light scatter (straylight). No studies have been performed to delineate the optical characteristics of PCO as a basis for explanation of these visual function defects. Methods Preparations of IOL-capsule combinations were harvested from donor eyes after removal of the cornea. They were mounted submersed in saline in an optical set-up, used earlier to characterize the optics of the crystalline lens (van den Berg et al. VR 1999). Illuminated by monochromatic beams of light, the light spreading originating from different areas of the preparation was measured as function of wavelength for different angles. Based on physical optics theory, the optical characteristics of PCO was derived. The data will be presented translated into the straylight parameter, directly comparable to the figures obtained in vivo using the clinical straylight meter (C-Quant from Oculus). Results Twenty successful preparations were harvested with at least some PCO areas. PCO grades varied from severe to slight. Two physically different types of light spreading could be discriminated. One type corresponding to pearl-like appearance, characterized by little wavelenght dependence and smal angle dominance. The other type corresponding to diffuse scatter, characterized by strong wavelength dependence and large angle dominance. The scatter values measured corresponded to clinical measures of straylight in PCO patients using the C-Quant. Conclusion The light scattering characteristics of PCO show two types of optical disturbance: a refractile type, probably dominated by pearl-like structures, and a diffuse type of scattering of yet unclear origin. [source] | ||||||||||