The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

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

  • A contrastive study of adsorption behaviors on Polyurethane Fiber with diester/diurethane tethered and non-tethered azo disperse dyes☆
    Dyes and Pigments, 2017
    Co-Authors: Hongfei Qian, Gaofeng Feng, Gang Bai, Yan-chun Liu
    Abstract:

    Abstract To look for a way to improve the fastness properties of disperse dyes on PU Fibers, six diurethane/diester tethered azo disperse dyes were prepared and applied to the dyeing of Polyurethane Fibers. Their detailed adsorption behaviors including the dyeing rate, build-up properties, surface-adsorbed state of dyes and colorimetric properties were investigated as well as compared with those of non-tethered azo dyes. The results showed that there were great differences in adsorption properties between the two types of dyes. The excellent build-up performance of the non-tethered dyes was caused by the crystal growth on the surface of Polyurethane Fibers, and the serious aggregation of dyes on the surface of Fibers would alter the color shade, decrease the chroma and produce poor colorfastness properties. When the tethered dyes were applied to Polyurethane Fibers, owing to their larger molecular sizes, a higher temperature (120 °C) was needed to finish the dyeing process within a conventional time of 30–40 min, and the crystal growth on the surface of Polyurethane Fibers was obviously restricted, so that the color of dyed PU Fibers became bright and the colorfastness was notably improved. With additional dye concentration, a medium color depth was obtained. It was further demonstrated that the tethering modification of azo disperse dyes to enhance the colorfastness on Polyurethane Fibers was feasible.

  • Dyeing of Polyurethane /Silk Blend with Temporarily Solubilised Disperse Dye
    2016
    Co-Authors: Hongfei Qian
    Abstract:

    Abstract. In this study, a temporarily solubilised disperse dye was prepared and applied to Polyurethane/silk blend to probe a new dyeing technology. The effect of pH on the dyeing of this blend at different dyeing temperatures was investigated. The optimum dyeing condition was found to be 75 °C and pH 8 at which the dyeing rate curves for two components in blend was measured respectively. Because of difference in substantivity, the transfer of dye from Polyurethane Fiber to silk occurred during dyeing of the blend. the dyeing equilibrium was nearly achieved by increasing the dyeing time to 80 min. Even distribution of dye between Polyurethane and silk, higher exhaustion on Polyurethane Fiber or fixation on silk as well as desirable fastness properties were obtained with this dye

  • Dyeing of Polyurethane/Silk Blend with Temporarily Solubilised Disperse Dye
    Advanced Materials Research, 2011
    Co-Authors: Hongfei Qian, Xinyuan Song
    Abstract:

    In this study, a temporarily solubilised disperse dye was prepared and applied to Polyurethane/silk blend to probe a new dyeing technology. The effect of pH on the dyeing of this blend at different dyeing temperatures was investigated. The optimum dyeing condition was found to be 75 °C and pH 8 at which the dyeing rate curves for two components in blend was measured respectively. Because of difference in substantivity, the transfer of dye from Polyurethane Fiber to silk occurred during dyeing of the blend. the dyeing equilibrium was nearly achieved by increasing the dyeing time to 80 min. Even distribution of dye between Polyurethane and silk, higher exhaustion on Polyurethane Fiber or fixation on silk as well as desirable fastness properties were obtained with this dye.

  • the structure of azo disperse dyes and its distribution on Polyurethane Fiber blend with polyester or polyamide Fiber
    Dyes and Pigments, 2007
    Co-Authors: Hongfei Qian, Xinyuan Song
    Abstract:

    Using a range of monoazo disperse dyes, the distributions between PU Fiber and polyester, and polyamide Fibers were studied. It was found that at lower temperature, the disperse dyes exhausted more on Polyurethane Fiber than on polyester or polyamide, and then less exhausted as the temperature was increased. The distributions on Polyurethane Fiber blends varied with the structure of disperse dyes. The presence of halogen groups on diazo component at the ortho position to the azo link made dye uptake on Polyurethane component higher, but the cyano derivative and the dye from diazo component of 5-nitro-benzothiazole tended to lower the adsorption on Polyurethane Fiber. The addition of two terminal cyano groups on coupling component showed lower dye uptake on Polyurethane. The dyes with two terminal hydroxyl groups had high exhaustion on Polyurethane Fiber when blended with polyester Fiber but low exhaustion when blended with polyamide.

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

  • Dyeing of Polyurethane/Silk Blend with Temporarily Solubilised Disperse Dye
    Advanced Materials Research, 2011
    Co-Authors: Hongfei Qian, Xinyuan Song
    Abstract:

    In this study, a temporarily solubilised disperse dye was prepared and applied to Polyurethane/silk blend to probe a new dyeing technology. The effect of pH on the dyeing of this blend at different dyeing temperatures was investigated. The optimum dyeing condition was found to be 75 °C and pH 8 at which the dyeing rate curves for two components in blend was measured respectively. Because of difference in substantivity, the transfer of dye from Polyurethane Fiber to silk occurred during dyeing of the blend. the dyeing equilibrium was nearly achieved by increasing the dyeing time to 80 min. Even distribution of dye between Polyurethane and silk, higher exhaustion on Polyurethane Fiber or fixation on silk as well as desirable fastness properties were obtained with this dye.

  • the structure of azo disperse dyes and its distribution on Polyurethane Fiber blend with polyester or polyamide Fiber
    Dyes and Pigments, 2007
    Co-Authors: Hongfei Qian, Xinyuan Song
    Abstract:

    Using a range of monoazo disperse dyes, the distributions between PU Fiber and polyester, and polyamide Fibers were studied. It was found that at lower temperature, the disperse dyes exhausted more on Polyurethane Fiber than on polyester or polyamide, and then less exhausted as the temperature was increased. The distributions on Polyurethane Fiber blends varied with the structure of disperse dyes. The presence of halogen groups on diazo component at the ortho position to the azo link made dye uptake on Polyurethane component higher, but the cyano derivative and the dye from diazo component of 5-nitro-benzothiazole tended to lower the adsorption on Polyurethane Fiber. The addition of two terminal cyano groups on coupling component showed lower dye uptake on Polyurethane. The dyes with two terminal hydroxyl groups had high exhaustion on Polyurethane Fiber when blended with polyester Fiber but low exhaustion when blended with polyamide.

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

  • enhanced friction of elastomer microFiber adhesives with spatulate tips
    Applied Physics Letters, 2007
    Co-Authors: Seok Kim, Burak Aksak, Metin Sitti
    Abstract:

    Previous studies have demonstrated that gecko foot-hair inspired elastomer microFibers with spatulate tips have significant adhesion enhancement compared to the flat elastomer surface. In this study, we report the friction enhancement of these highly adhesive Fibers and analyze the relation between adhesion and friction of elastomer microFiber arrays with spatulate tips. Fabricated Polyurethane Fiber arrays with spatulate tips demonstrate macroscale static friction pressures up to 41N∕cm2 for a preload pressure of 1.5N∕cm2 on a 6mm diameter smooth glass hemisphere.

  • Biologically inspired polymer microFibers with spatulate tips as repeatable fibrillar adhesives
    Applied Physics Letters, 2006
    Co-Authors: Seok Kim, Metin Sitti
    Abstract:

    Being inspired by gecko foot hairs, microFibers with flat spatulate tips are proposed as repeatable adhesives. They are fabricated by molding a master template fabricated using deep reactive ion etching and the notching effect. Fabricated Polyurethane Fiber arrays with 4.5μm Fiber and 9μm tip diameter demonstrated macroscale adhesion pressures up to 18N∕cm2 and overall work of adhesion up to 11J∕m2 on a 6mm diameter glass hemisphere for a preload pressure of 12N∕cm2. These results show around four times higher adhesion and five times higher overall work of adhesion as compared to the flat Polyurethane surface.

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

  • enhanced friction of elastomer microFiber adhesives with spatulate tips
    Applied Physics Letters, 2007
    Co-Authors: Seok Kim, Burak Aksak, Metin Sitti
    Abstract:

    Previous studies have demonstrated that gecko foot-hair inspired elastomer microFibers with spatulate tips have significant adhesion enhancement compared to the flat elastomer surface. In this study, we report the friction enhancement of these highly adhesive Fibers and analyze the relation between adhesion and friction of elastomer microFiber arrays with spatulate tips. Fabricated Polyurethane Fiber arrays with spatulate tips demonstrate macroscale static friction pressures up to 41N∕cm2 for a preload pressure of 1.5N∕cm2 on a 6mm diameter smooth glass hemisphere.

  • Biologically inspired polymer microFibers with spatulate tips as repeatable fibrillar adhesives
    Applied Physics Letters, 2006
    Co-Authors: Seok Kim, Metin Sitti
    Abstract:

    Being inspired by gecko foot hairs, microFibers with flat spatulate tips are proposed as repeatable adhesives. They are fabricated by molding a master template fabricated using deep reactive ion etching and the notching effect. Fabricated Polyurethane Fiber arrays with 4.5μm Fiber and 9μm tip diameter demonstrated macroscale adhesion pressures up to 18N∕cm2 and overall work of adhesion up to 11J∕m2 on a 6mm diameter glass hemisphere for a preload pressure of 12N∕cm2. These results show around four times higher adhesion and five times higher overall work of adhesion as compared to the flat Polyurethane surface.

Ding-xiang Yan - One of the best experts on this subject based on the ideXlab platform.