Reactivity of Gas Barrier Membranes Filled with Reactive Particulates

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• 作者：Stanislav E. Solovyov
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：September 14, 2006
• 年：2006
• 卷：110
• 期：36
• 页码：17977 - 17986
• 全文大小：295K
• 年卷期：v.110,no.36(September 14, 2006)
• ISSN：1520-5207

文摘

Gas barrier plastic films and structures capable of removing a permeating solute via irreversible chemicalreactions in the polymer matrix are investigated in applications of active packaging for controlling containedenvironments. To significantly reduce permeation rates through such active barriers, high barrier reactivity isrequired. When the reactive species take the form of fine particulates sparingly dispersed in the matrix, thereactivity of a composite membrane is affected by a lower frequency of collisions of dissolved gas moleculeswith the distributed reactive particles. The mean size of the particles and their volume fraction in the matrixare identified as the critical factors affecting the overall reactivity of uniformly filled composite barriers. Atwo-scale coarse-grained model of reaction-diffusion in a matrix is developed by introducing a unit cellapproach to estimate the reaction rate upon collision with the particles and by choosing the unit length ofdiffusive molecular displacement equal to the mean diameter of the reactive particles to describe diffusionacross the barrier and statistics of molecule-particle collisions. The corresponding method for evaluating thebarrier reactivity is described. The effects of the system parameters on the effective gas transport rates acrossthe reactive composite barriers including polymer nanocomposite barriers with reactive additives are quantified.