A study on characterization of S.T.E.P technology for polymeric nano solution and multifunctional applications
| Autor: | CHI-YUNG CHANG, 張琪詠 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this study, we aim to establish a complete dispersibility analysis system for polymeric nanosolution, and analyzing of properties and applications for multifunctional coatings as well. The synthesis of multifunctional coatings is by adding nanoparticles into polymeric solution or using foaming technique to obtain polymeric micro-foam solution. The great stable of nanosolution is obtained by optimizing materials selection and processing parameter. The multisample analytical centrifuge (LUMiSizer, L.U.M. GmbH, Berlin Germany) used in this study employs S.T.E.P technology (Space and Time resolved Extiction Profile), which allows to measure the intensity of the transmitted light as function of time and position over the entire sample length simultaneously. While the variation of the light extinction curves after centrifugal segregation provided a qualitative description, a rigorous formulation can provide detailed quantitative characterization. By this method, the dispersibility and shelf life of multifunctional nanosolution and effects of nanoparticles content and processing time on dispersiblity can be characterized easily. It also determines the particle size distribution of multifunctional coatings; the results were comparable with those obtained using dynamic light scattering, scanning electron microscope and zeta potential analysis. This study has addressed three parts respectively to discuss the applications of S.T.E.P technology on analyzing multifunctional nanosolution and evaluating the performances. Part (i) describes the dispersibility and particle size distributions of nanocomposite coatings. The LUMiSizerR analytical centrifuge with STEP technology can determine the particle dispersion and size distribution of multisample organic/inorganic composite coatings. The stability of the coatings increases upon increasing the dispersant concentration, and decreases upon increasing the binder concentration. Dispersibility measurements reveals that the coating sample with higher dispersant concentration exhibits the best stabilizing performance without agglomeration, due to its lowest sedimentation rate, determining through shelf-life predictions with the LUMiSizerR and its highest absolute zeta potential. The dispersibility results obtain from the zeta potential and LUMiSizerR data are consistent and precise. Using DLS and SEM to determine PSDs provided results that are similar to those obtained using the LUMiSizerR. The particle sizes decrease with high dispersibility and increase with low dispersibility. Part (ii) describes the stability and application in medical packaging of polyurethane foam coatings. The preparation of PUFs with various foam densities are through mechanical foaming and then coated PUFs of different foam densities onto TyvekR medical paper at different thicknesses. The PUF coating with higher foam density has the highest stability. SEM imagings reveal that the cell size of the PUF coats decrease and the cell density of the PUF coats increase upon increasing the foam density respectively. The PUF coat with higher foam density exhibits low tackiness |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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