The Experts below are selected from a list of 61707 Experts worldwide ranked by ideXlab platform

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

  • Polyacrylate/silica nanocomposite materials prepared by Sol–Gel Process
    European Polymer Journal, 2007
    Co-Authors: Jianzhong Ma, Jing Hu, Zhijie Zhang
    Abstract:

    Abstract Polyacrylate/silica nanocomposite was prepared by Sol–Gel Process via in situ emulsion polymerization. The influence of the synthetic conditions, such as the ratio of different monomers and the contents of tetraethoxysilane (TEOS), γ-methacryloxypropyltrimethoxysilane (Z-6030), diethanolamine (DAM) and ammonium persulfate (APS) on the physical mechanical properties of polyacrylate/silica nanocomposite was investigated in details. Dynamics Laser Scattering (DLS) indicated that the average diameter of the polyacrylate/silica latex particles (177 nm) was bigger than that of the pure polyacrylate latex particles (105.3 nm), but the ζ potential of polyacrylate/silica was decreased respectively in contrast to that of the polyacrylate. Differential Scanning Calorimeters (DSC) analysis confirmed that the glass transition temperature of polyacrylate/nano-SiO2 (Tg = −24 °C) was higher than that of polyacrylate (Tg = −36 °C). UV analysis showed that the UV absorbency of polyacrylate/silica was improved evidently in contrast to that of polyacrylate.

  • polyacrylate silica nanocomposite materials prepared by Sol Gel Process
    European Polymer Journal, 2007
    Co-Authors: Zhijie Zhang
    Abstract:

    Abstract Polyacrylate/silica nanocomposite was prepared by Sol–Gel Process via in situ emulsion polymerization. The influence of the synthetic conditions, such as the ratio of different monomers and the contents of tetraethoxysilane (TEOS), γ-methacryloxypropyltrimethoxysilane (Z-6030), diethanolamine (DAM) and ammonium persulfate (APS) on the physical mechanical properties of polyacrylate/silica nanocomposite was investigated in details. Dynamics Laser Scattering (DLS) indicated that the average diameter of the polyacrylate/silica latex particles (177 nm) was bigger than that of the pure polyacrylate latex particles (105.3 nm), but the ζ potential of polyacrylate/silica was decreased respectively in contrast to that of the polyacrylate. Differential Scanning Calorimeters (DSC) analysis confirmed that the glass transition temperature of polyacrylate/nano-SiO2 (Tg = −24 °C) was higher than that of polyacrylate (Tg = −36 °C). UV analysis showed that the UV absorbency of polyacrylate/silica was improved evidently in contrast to that of polyacrylate.

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

  • organic pigment particles coated with titania via Sol Gel Process
    Journal of Physical Chemistry B, 2006
    Co-Authors: Junjie Yuan, Shuxue Zhou, Limin Wu
    Abstract:

    This paper presented a novel method for the organic pigment coated with titania to improve the weatherability and dispersion ability in waterborne system. The organic pigment was first orderly adsorbed by two kinds of electrolyte:  poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), then coated by titania via Sol−Gel Process from titanium n-butoxide (TBOT). The effects of the numbers of polyelectrolyte layer, water content, and TBOT content on the morphology, particle size, surface element composition, porosity and pore size, thermal stability, and UV shielding property of the organic pigment were systematically investigated. It was found that only two layers of electrolyte adsorption and one-step coating of titania could obviously enhance the UV shielding property even thermal stability of the organic pigment. The thickness of the titania layer could be easily tailored by TBOT content.

  • Organic Pigment Particles Coated with Titania via Sol−Gel Process
    Journal of Physical Chemistry B, 2006
    Co-Authors: Junjie Yuan, Shuxue Zhou, Limin Wu
    Abstract:

    This paper presented a novel method for the organic pigment coated with titania to improve the weatherability and dispersion ability in waterborne system. The organic pigment was first orderly adsorbed by two kinds of electrolyte:  poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), then coated by titania via Sol−Gel Process from titanium n-butoxide (TBOT). The effects of the numbers of polyelectrolyte layer, water content, and TBOT content on the morphology, particle size, surface element composition, porosity and pore size, thermal stability, and UV shielding property of the organic pigment were systematically investigated. It was found that only two layers of electrolyte adsorption and one-step coating of titania could obviously enhance the UV shielding property even thermal stability of the organic pigment. The thickness of the titania layer could be easily tailored by TBOT content.

  • Encapsulation of Organic Pigment Particles with Silica via Sol-Gel Process
    Journal of Sol-Gel Science and Technology, 2005
    Co-Authors: Junjie Yuan, Guangxin Gu, Shuxue Zhou, Limin Wu
    Abstract:

    This paper presented a novel preparation method of silica coated organic pigment. In this approach, the surfaces of the organic pigment were first orderly modified by poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), then coated by silica via Sol-Gel Process of tetraethylorthosilicate (TEOS). The results showed that PVP, pH value, water and TEOS contents had significant influence on the morphology of the silica encapsulated organic pigment. Organic pigments coated silica by this approach could scatter UV ray with wavelength less than 270 nm, and this scattering property increased with more silica coated.

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

  • Polyacrylate/silica nanocomposite materials prepared by Sol–Gel Process
    European Polymer Journal, 2007
    Co-Authors: Jianzhong Ma, Jing Hu, Zhijie Zhang
    Abstract:

    Abstract Polyacrylate/silica nanocomposite was prepared by Sol–Gel Process via in situ emulsion polymerization. The influence of the synthetic conditions, such as the ratio of different monomers and the contents of tetraethoxysilane (TEOS), γ-methacryloxypropyltrimethoxysilane (Z-6030), diethanolamine (DAM) and ammonium persulfate (APS) on the physical mechanical properties of polyacrylate/silica nanocomposite was investigated in details. Dynamics Laser Scattering (DLS) indicated that the average diameter of the polyacrylate/silica latex particles (177 nm) was bigger than that of the pure polyacrylate latex particles (105.3 nm), but the ζ potential of polyacrylate/silica was decreased respectively in contrast to that of the polyacrylate. Differential Scanning Calorimeters (DSC) analysis confirmed that the glass transition temperature of polyacrylate/nano-SiO2 (Tg = −24 °C) was higher than that of polyacrylate (Tg = −36 °C). UV analysis showed that the UV absorbency of polyacrylate/silica was improved evidently in contrast to that of polyacrylate.

Anup K. Singh - One of the best experts on this subject based on the ideXlab platform.

  • aqueous Sol Gel Process for protein encapsulation
    Chemistry of Materials, 2000
    Co-Authors: Rimple Bhatia B And, Jeffrey C Brinker, Alok Gupta K And, Anup K. Singh
    Abstract:

    Porous silica materials made by low-temperature Sol−Gel Process are promising host matrixes for encapsulation of biomolecules. To date, researchers have focused on Sol−Gel routes using alkoxides such as tetramethyl orthosilicate (TMOS) and tetraethyl orthosilicate (TEOS) for encapsulation of biomolecules. These routes lead to formation of alcohol as a byproduct that can have a detrimental effect on the activity of entrapped biomolecules. We have developed a novel aqueous Sol−Gel Process to encapsulate biological molecules (such as enzymes, antibodies, and cells) that uses neutral pH and room temperature and does not generate alcohol as a byproduct. The Process uses sodium silicate as precursor and is carried out in two steps:  preparation of a low-pH silicate Sol followed by Gelation at neutral pH with a suitable buffer containing biomolecules. Two enzymes widely used in biosensing applications, horseradish peroxidase (HRP) and glucose-6-phosphate dehydrogenase (G6PDH), were used to prepare enzyme-doped s...

  • Aqueous Sol−Gel Process for Protein Encapsulation
    Chemistry of Materials, 2000
    Co-Authors: Rimple B. Bhatia† And, C. Jeffrey Brinker, Alok K. Gupta And, Anup K. Singh
    Abstract:

    Porous silica materials made by low-temperature Sol−Gel Process are promising host matrixes for encapsulation of biomolecules. To date, researchers have focused on Sol−Gel routes using alkoxides such as tetramethyl orthosilicate (TMOS) and tetraethyl orthosilicate (TEOS) for encapsulation of biomolecules. These routes lead to formation of alcohol as a byproduct that can have a detrimental effect on the activity of entrapped biomolecules. We have developed a novel aqueous Sol−Gel Process to encapsulate biological molecules (such as enzymes, antibodies, and cells) that uses neutral pH and room temperature and does not generate alcohol as a byproduct. The Process uses sodium silicate as precursor and is carried out in two steps:  preparation of a low-pH silicate Sol followed by Gelation at neutral pH with a suitable buffer containing biomolecules. Two enzymes widely used in biosensing applications, horseradish peroxidase (HRP) and glucose-6-phosphate dehydrogenase (G6PDH), were used to prepare enzyme-doped s...

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

  • organic pigment particles coated with titania via Sol Gel Process
    Journal of Physical Chemistry B, 2006
    Co-Authors: Junjie Yuan, Shuxue Zhou, Limin Wu
    Abstract:

    This paper presented a novel method for the organic pigment coated with titania to improve the weatherability and dispersion ability in waterborne system. The organic pigment was first orderly adsorbed by two kinds of electrolyte:  poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), then coated by titania via Sol−Gel Process from titanium n-butoxide (TBOT). The effects of the numbers of polyelectrolyte layer, water content, and TBOT content on the morphology, particle size, surface element composition, porosity and pore size, thermal stability, and UV shielding property of the organic pigment were systematically investigated. It was found that only two layers of electrolyte adsorption and one-step coating of titania could obviously enhance the UV shielding property even thermal stability of the organic pigment. The thickness of the titania layer could be easily tailored by TBOT content.

  • Organic Pigment Particles Coated with Titania via Sol−Gel Process
    Journal of Physical Chemistry B, 2006
    Co-Authors: Junjie Yuan, Shuxue Zhou, Limin Wu
    Abstract:

    This paper presented a novel method for the organic pigment coated with titania to improve the weatherability and dispersion ability in waterborne system. The organic pigment was first orderly adsorbed by two kinds of electrolyte:  poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), then coated by titania via Sol−Gel Process from titanium n-butoxide (TBOT). The effects of the numbers of polyelectrolyte layer, water content, and TBOT content on the morphology, particle size, surface element composition, porosity and pore size, thermal stability, and UV shielding property of the organic pigment were systematically investigated. It was found that only two layers of electrolyte adsorption and one-step coating of titania could obviously enhance the UV shielding property even thermal stability of the organic pigment. The thickness of the titania layer could be easily tailored by TBOT content.

  • Encapsulation of Organic Pigment Particles with Silica via Sol-Gel Process
    Journal of Sol-Gel Science and Technology, 2005
    Co-Authors: Junjie Yuan, Guangxin Gu, Shuxue Zhou, Limin Wu
    Abstract:

    This paper presented a novel preparation method of silica coated organic pigment. In this approach, the surfaces of the organic pigment were first orderly modified by poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), then coated by silica via Sol-Gel Process of tetraethylorthosilicate (TEOS). The results showed that PVP, pH value, water and TEOS contents had significant influence on the morphology of the silica encapsulated organic pigment. Organic pigments coated silica by this approach could scatter UV ray with wavelength less than 270 nm, and this scattering property increased with more silica coated.