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Michael V Pishko - One of the best experts on this subject based on the ideXlab platform.

  • release of protein from highly cross linked hydrogels of poly ethylene glycol diacrylate fabricated by uv Polymerization
    Biomaterials, 2001
    Co-Authors: Michael B Mellott, Katherine Searcy, Michael V Pishko
    Abstract:

    Highly crosslinked hydrogel spheres were fabricated using UV photoPolymerization of poly(ethylene glycol) diacrylate (PEG-DA) and pentaerythritol triacrylate (PETA) with 2,2-dimethoxy-2-phenyl-acetophenone (DMPA) as the photoinitiator. Spheres were fabricated both with and without one of three comonomers: acrylic acid, acrylamide or allylamine. PhotoPolymerization rates and Polymer Morphology were determined using attenuated total re#ectance/Fourier transforminfrared spectroscopy and electron microscopy, respectively. These gels were further characterized for volume change, equilibrium water content, di!usivity of the expanding gel, molecular weight between crosslinks and Polymer mesh size. Hydrogels with comonomers generally demonstrated an increase in equilibrium water content, average molecular weight between crosslinks and mesh size. Bovine serum albumin was incorporated into the hydrogel to simulate delivery of a model protein drug. The protein di!usion coe$cients, based a Fickian release model, were calculated to be between 10 and 10 cm/s with slight variance due to PETA concentration and the type of comonomer used. 2001 Elsevier Science Ltd. All rights reserved.

  • release of protein from highly cross linked hydrogels of poly ethylene glycol diacrylate fabricated by uv Polymerization
    Biomaterials, 2001
    Co-Authors: Michael B Mellott, Katherine Searcy, Michael V Pishko
    Abstract:

    Highly crosslinked hydrogel spheres were fabricated using UV photoPolymerization of poly(ethylene glycol) diacrylate (PEG-DA) and pentaerythritol triacrylate (PETA) with 2,2'-dimethoxy-2-phenyl-acetophenone (DMPA) as the photoinitiator. Spheres were fabricated both with and without one of three comonomers: acrylic acid, acrylamide or allylamine. PhotoPolymerization rates and Polymer Morphology were determined using attenuated total reflectance/Fourier transform infrared spectroscopy and electron microscopy, respectively. These gels were further characterized for volume change, equilibrium water content, diffusivity of the expanding gel, molecular weight between crosslinks and Polymer mesh size. Hydrogels with comonomers generally demonstrated an increase in equilibrium water content, average molecular weight between crosslinks and mesh size. Bovine serum albumin was incorporated into the hydrogel to simulate delivery of a model protein drug. The protein diffusion coefficients, based a Fickian release model, were calculated to be between 10(-10) and 10(-12) cm2/s with slight variance due to PETA concentration and the type of comonomer used.

Yang Yang - One of the best experts on this subject based on the ideXlab platform.

  • Recent progress in Polymer solar cells: Manipulation of Polymer: Fullerene Morphology and the formation of efficient inverted Polymer solar cells
    Advanced Materials, 2009
    Co-Authors: Li Min Chen, Ziruo Hong, Gang Li, Yang Yang
    Abstract:

    Polymer Morphology has proven to be extremely important in determining the optoelectronic properties in Polymer-based devices. The understanding and manipulation of Polymer Morphology has been the focus of electronic and optoelectronic Polymer-device research. In this article, recent advances in the understanding and controlling of Polymer Morphology are reviewed with respect to the solvent selection and various annealing processes. We also review the mixed-solvent effects on the dynamics of film evolution in selected Polymer-blend systems, which facilitate the formation of optimal percolation paths and therefore provide a simple approach to improve photovoltaic performance. Recently, the occurrence of vertical phase separation has been found in some Polymer:fullerene bulk heterojunctions.([1-3]) The origin and applications of this inhomogeneous distribution of the Polymer donor and fullerene acceptor are addressed. The current status and device physics of the inverted structure solar cells is also reviewed, including the advantage of utilizing the spontaneous vertical phase separation, which provides a promising alternative to the conventional structure for obtaining higher device performance

  • solvation induced Morphology effects on the performance of Polymer based photovoltaic devices
    Advanced Functional Materials, 2001
    Co-Authors: Jie Liu, Yijian Shi, Yang Yang
    Abstract:

    Polymer-based photovoltaic devices have been fabricated by blending the conjugated Polymer, poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) with the buckminsterfullerene, C60. The photo-induced current and the open-circuit voltage show a strong dependence on the Polymer processing conditions. It was found that the photovoltaic devices fabricated with tetrahydrofuran or chloroform (non-aromatic solvents) have smaller photocurrents under same reverse bias as well as higher open circuit voltages than the devices fabricated with xylene, dichlorobenzene, or chlorobenzene (aromatic solvents). The device performance dependence on the processing solvent is attributed to the different solvation-induced Polymer Morphology.

  • Device performance and Polymer Morphology in Polymer light emitting diodes: The control of thin film Morphology and device quantum efficiency
    Journal of Applied Physics, 2000
    Co-Authors: Yijian Shi, Jizhao Liu, Yang Yang
    Abstract:

    We present the results of a systematic study on how the processing conditions of spin casting affect the Morphology of Polymer thin films, and how the Morphology affects Polymer light-emitting diode (LED) performance. The absorption peaks of poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1, 4-phenylene vinylene) (MEH-PPV) thin films, which reflects the conjugation of π electrons, are strongly correlated to the spin-casting conditions. At high spin speed, better conjugation is observed. In addition, the photoluminescence emission peak of MEH-PPV films at ∼630 nm has a strong correlation to Polymer aggregation. By proper selection of organic solvents, Polymer solution concentrations, and spin speeds, we are able to control the aggregation of the Polymer chains. Subsequently, we are able to control the emission color and the quantum efficiency of the MEH-PPV LEDs by simply adjusting the spin-casting conditions. Although spin casting is the most commonly used technique for the preparation of Polymer thin films, our fin...

Michael B Mellott - One of the best experts on this subject based on the ideXlab platform.

  • release of protein from highly cross linked hydrogels of poly ethylene glycol diacrylate fabricated by uv Polymerization
    Biomaterials, 2001
    Co-Authors: Michael B Mellott, Katherine Searcy, Michael V Pishko
    Abstract:

    Highly crosslinked hydrogel spheres were fabricated using UV photoPolymerization of poly(ethylene glycol) diacrylate (PEG-DA) and pentaerythritol triacrylate (PETA) with 2,2-dimethoxy-2-phenyl-acetophenone (DMPA) as the photoinitiator. Spheres were fabricated both with and without one of three comonomers: acrylic acid, acrylamide or allylamine. PhotoPolymerization rates and Polymer Morphology were determined using attenuated total re#ectance/Fourier transforminfrared spectroscopy and electron microscopy, respectively. These gels were further characterized for volume change, equilibrium water content, di!usivity of the expanding gel, molecular weight between crosslinks and Polymer mesh size. Hydrogels with comonomers generally demonstrated an increase in equilibrium water content, average molecular weight between crosslinks and mesh size. Bovine serum albumin was incorporated into the hydrogel to simulate delivery of a model protein drug. The protein di!usion coe$cients, based a Fickian release model, were calculated to be between 10 and 10 cm/s with slight variance due to PETA concentration and the type of comonomer used. 2001 Elsevier Science Ltd. All rights reserved.

  • release of protein from highly cross linked hydrogels of poly ethylene glycol diacrylate fabricated by uv Polymerization
    Biomaterials, 2001
    Co-Authors: Michael B Mellott, Katherine Searcy, Michael V Pishko
    Abstract:

    Highly crosslinked hydrogel spheres were fabricated using UV photoPolymerization of poly(ethylene glycol) diacrylate (PEG-DA) and pentaerythritol triacrylate (PETA) with 2,2'-dimethoxy-2-phenyl-acetophenone (DMPA) as the photoinitiator. Spheres were fabricated both with and without one of three comonomers: acrylic acid, acrylamide or allylamine. PhotoPolymerization rates and Polymer Morphology were determined using attenuated total reflectance/Fourier transform infrared spectroscopy and electron microscopy, respectively. These gels were further characterized for volume change, equilibrium water content, diffusivity of the expanding gel, molecular weight between crosslinks and Polymer mesh size. Hydrogels with comonomers generally demonstrated an increase in equilibrium water content, average molecular weight between crosslinks and mesh size. Bovine serum albumin was incorporated into the hydrogel to simulate delivery of a model protein drug. The protein diffusion coefficients, based a Fickian release model, were calculated to be between 10(-10) and 10(-12) cm2/s with slight variance due to PETA concentration and the type of comonomer used.

Katherine Searcy - One of the best experts on this subject based on the ideXlab platform.

  • release of protein from highly cross linked hydrogels of poly ethylene glycol diacrylate fabricated by uv Polymerization
    Biomaterials, 2001
    Co-Authors: Michael B Mellott, Katherine Searcy, Michael V Pishko
    Abstract:

    Highly crosslinked hydrogel spheres were fabricated using UV photoPolymerization of poly(ethylene glycol) diacrylate (PEG-DA) and pentaerythritol triacrylate (PETA) with 2,2-dimethoxy-2-phenyl-acetophenone (DMPA) as the photoinitiator. Spheres were fabricated both with and without one of three comonomers: acrylic acid, acrylamide or allylamine. PhotoPolymerization rates and Polymer Morphology were determined using attenuated total re#ectance/Fourier transforminfrared spectroscopy and electron microscopy, respectively. These gels were further characterized for volume change, equilibrium water content, di!usivity of the expanding gel, molecular weight between crosslinks and Polymer mesh size. Hydrogels with comonomers generally demonstrated an increase in equilibrium water content, average molecular weight between crosslinks and mesh size. Bovine serum albumin was incorporated into the hydrogel to simulate delivery of a model protein drug. The protein di!usion coe$cients, based a Fickian release model, were calculated to be between 10 and 10 cm/s with slight variance due to PETA concentration and the type of comonomer used. 2001 Elsevier Science Ltd. All rights reserved.

  • release of protein from highly cross linked hydrogels of poly ethylene glycol diacrylate fabricated by uv Polymerization
    Biomaterials, 2001
    Co-Authors: Michael B Mellott, Katherine Searcy, Michael V Pishko
    Abstract:

    Highly crosslinked hydrogel spheres were fabricated using UV photoPolymerization of poly(ethylene glycol) diacrylate (PEG-DA) and pentaerythritol triacrylate (PETA) with 2,2'-dimethoxy-2-phenyl-acetophenone (DMPA) as the photoinitiator. Spheres were fabricated both with and without one of three comonomers: acrylic acid, acrylamide or allylamine. PhotoPolymerization rates and Polymer Morphology were determined using attenuated total reflectance/Fourier transform infrared spectroscopy and electron microscopy, respectively. These gels were further characterized for volume change, equilibrium water content, diffusivity of the expanding gel, molecular weight between crosslinks and Polymer mesh size. Hydrogels with comonomers generally demonstrated an increase in equilibrium water content, average molecular weight between crosslinks and mesh size. Bovine serum albumin was incorporated into the hydrogel to simulate delivery of a model protein drug. The protein diffusion coefficients, based a Fickian release model, were calculated to be between 10(-10) and 10(-12) cm2/s with slight variance due to PETA concentration and the type of comonomer used.

Ian A. Nicholls - One of the best experts on this subject based on the ideXlab platform.