http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Development of Nanodomain and Fractal Morphologies in Solvent Annealed Block Copolymer Thin Films
Peng, Juan,Han, Yanchun,Knoll, Wolfgang,Kim, Dong Ha Hu@thig & Wepf 2007 Macromolecular Rapid Communications Vol.28 No.13
<P>We have systematically studied the thin film morphologies of asymmetric polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer subjected to solvent vapors of varying selectivity for the constituent blocks. Upon a short treatment in neutral or PS-selective vapor, the film exhibited a highly ordered array of hexagonally packed, cylindrical microdomains. In the case of PEO selective vapor annealing, such ordered cylindrical microdomains were not obtained. Instead, fractal patterns on the microscale were observed and their growth processes investigated. Furthermore, hierarchical structures could be obtained if the fractal pattern was exposed to neutral or PS selective vapor.</P><P> <img src='wiley_img/10221336-2007-28-13-MARC200700206-gra001.gif' alt='wiley_img/10221336-2007-28-13-MARC200700206-gra001'> </P>
Lau, King Hang Aaron,Knoll, Wolfgang,Kim, Dong-Ha The Polymer Society of Korea 2007 Macromolecular Research Vol.15 No.3
Hybrid thin film nanostructures composed of metal nanoparticles (NPs) and self-assembled polymer films with different spatial distributions of NPs were analyzed by optical waveguide spectroscopy (OWS). Specifically, the dielectric constants were calculated using effective medium theory for the incorporation of 1 vol% Au NP into the block copolymer (BCP) films having a cylindrical nanodomain morphology. Three cases were considered: uniform distribution of NPs in the film; selective distribution of NPs only in the cylindrical domains; and segregation of NPs to the center of the cylindrical domains. The optical waveguide spectra derived from the calculated dielectric constants demonstrate the feasibility of experimentally distinguishing the composite nanostructures with different inner morphologies in the hybrid metal NP-BCP nanostructures, by the measurement of the dielectric constants using OWS.
Peng, Juan,Li, Xue,Kim, Dong Ha,Knoll, Wolfgang WILEY-VCH Verlag 2007 Macromolecular Rapid Communications Vol.28 No.21
<P>We report a simple scheme to fabricate organic/inorganic hybrid nanostructures with extraordinary morphologies by one-step spin coating, using a PS-b-PEO diblock copolymer as template coupled with sol-gel chemistry. The shape and size of the titania nanoobject can be fine-tuned by controlling the amount of sol-gel precursor relative to PS-b-PEO and the composition of the precursor. Ordered arrays of nanoscopic titania objects such as nanodots, nanobowls, and nanonetworks were obtained from the initial hybrid nanostructures by removing the organic matrix by UV treatment. Photocatalytic activities of the resulting titania nanoobjects were investigated in terms of the degradation of a typical dye.</P><P> <img src='wiley_img/10221336-2007-28-21-MARC200700430-gra001.gif' alt='wiley_img/10221336-2007-28-21-MARC200700430-gra001'> </P>
Xue Li,Jun Fu,Martin Steinhart,김동하,Wolfgang Knoll 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.6
A simple approach to prepare arrays of Au/TiO2 composite nanoparticles by using Au-loaded block copolymers as templates combined with a sol-gel process is described. The organic-inorganic hybrid films with closely packed inorganic nanodomains in organic matrix are produced by spin coating the mixtures of polystyrene-block-poly(ethylene oxide) (PS-b-PEO)/HAuCl4 solution and sol-gel precursor solution. After removal of the organic matrix with deep UV irradiation, arrays of Au?/?TiO2 composite nanoparticles with different compositions or particle sizes can be easily produced. Different photoluminescence (PL) emission spectra from an organic-inorganic hybrid film and arrays of Au/TiO2 composite nanoparticles indicate that TiO2 and Au components exist as separate state in the initial hybrid film and form composite nanoparticles after the removal of the block copolymer matrix.
Aqueous Networks and Toroids of Amphiphilic Block Copolymer with Non-ionic Surfactants
Fu, Jun,Kim, Dong Ha,Knoll, Wolfgang WILEY-VCH Verlag 2009 CHEMPHYSCHEM -WEINHEIM- Vol.10 No.8
<P>Network formation: Comicellization of polystyrene-block-polyethylene oxide (PS–PEO) with non-ionic surfactants leads to the formation of networks and chains of spheres. The aqueous network solutions are responsive to dilution, undergoing morphological transformations to cylinders with Y junctions and both two- and three-dimensional toroids (see figure). <img src='wiley_img/14394235-2009-10-8-CPHC200900081-content.gif' alt='wiley_img/14394235-2009-10-8-CPHC200900081-content'> </P> <B>Graphic Abstract</B> <P>Network formation: Comicellization of polystyrene-block-polyethylene oxide (PS–PEO) with non-ionic surfactants leads to the formation of networks and chains of spheres. The aqueous network solutions are responsive to dilution, undergoing morphological transformations to cylinders with Y junctions and both two- and three-dimensional toroids (see figure). <img src='wiley_img/14394235-2009-10-8-CPHC200900081-content.gif' alt='wiley_img/14394235-2009-10-8-CPHC200900081-content'> </P>
Khan, Hadayat Ullah,Jang, Junhyuk,Kim, Jang-Joo,Knoll, Wolfgang American Chemical Society 2011 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.133 No.7
<P>Pentacene-based organic thin-film transistors were used to create highly sensitive, real-time electronic sensors for selective antibody detection. Bovine serum albumin was covalently attached to a modified pentacene surface to selectively detect the label free monoclonal antiBSA. These sensors displayed a high affinity constant (<I>K</I><SUB>A</SUB>) of (1.1 ± 3) × 10<SUP>7</SUP> M<SUP>−1</SUP> at pH 7, which is 1 order of magnitude higher than those obtained with a highly sensitive surface plasmon resonance spectroscopy detection system. Furthermore, a high degree of discrimination in the hybrid antiBSA charges was achieved at different pH values. This demonstration of fast, label-free, real-time detection of nanoscale biomolecules in aqueous buffer solutions using the organic transistor sensing platform will have a significant impact on high-performance microarrays in addition to discriminating the presence of ionizable groups.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2010/jacsat.2010.133.issue-7/ja107088m/production/images/medium/ja-2010-07088m_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja107088m'>ACS Electronic Supporting Info</A></P>
Li, Xue,Fu, Jun,Steinhart, Martin,Kim, Dong-Ha,Knoll, Wolfgang Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.6
A simple approach to prepare arrays of Au/TiO2 composite nanoparticles by using Au-loaded block copolymers as templates combined with a sol-gel process is described. The organic-inorganic hybrid films with closely packed inorganic nanodomains in organic matrix are produced by spin coating the mixtures of polystyrene-block-poly(ethylene oxide) (PS-b-PEO)/HAuCl4 solution and sol-gel precursor solution. After removal of the organic matrix with deep UV irradiation, arrays of Au/TiO2 composite nanoparticles with different compositions or particle sizes can be easily produced. Different photoluminescence (PL) emission spectra from an organic-inorganic hybrid film and arrays of Au/TiO2 composite nanoparticles indicate that TiO2 and Au components exist as separate state in the initial hybrid film and form composite nanoparticles after the removal of the block copolymer matrix.