Kinetic and equilibrium sorption of organic liquids and vapors in Matrimid

Abstract

This work examines the sorption, diffusion, and polymer relaxation behavior for a variety of organic penetrants in Matrimid. The diffusionrelaxation model for plasticizing penetrants in glassy polymers developed by Berens and Hopfenberg appropriately captures the kinetic behavior of the organic vapor/polymer systems.

Effect of vapor phase ethylenediamine crosslinking of matrimid on alcohol vapor sorption and diffusion

“…In further investigations, one may also consider the relative mobility of polymer chains as a function of temperature and the possible use of an additional vapor penetrant (i.e. one of the alcohols extensively studied in our previous work) to induce swelling of the polymer matrix and allow enhanced polymer chain motion. This approach may produce a greater degree of crosslinking as opposed to EDA exposure alone.…”

“…Vapor sorption experiments were performed with Matrimid spin‐coated AT‐cut quartz crystals. The vapor sorption experimental setup is shown in Figure and the procedural details are explained in depth in our previous work . Unmodified and crosslinked Matrimid films were exposed to each 0.2 P / P sat increment for each penetrant for 48 h, except pentanol, which required 76 h to reach equilibrium.…”

“…This mathematical relation is known as the Sauerbrey equation: where is the frequency change, is the mass change, is the fundamental frequency of the uncoated crystal, is the active area of one face of the crystal, is the shear modulus of quartz (29.47 GPa), and is the density of quartz (2.648 g/cm 3 ). Our previous work further discusses this technique and its potential limits and measurement errors . Other literature describes limitations and errors associated with QCM measurements due to material viscoelastic properties, film thickness, crystal imperfections, temperature, and pressure effects, however, most agree that glassy polymeric films with thicknesses less than 5.0 µm produce acceptable mass uptake measurements when conducted at near ambient temperature and pressure.…”

“…Diffusion coefficients and relaxation parameters for the penetrants in EDA crosslinked Matrimid are calculated using the diffusion‐relaxation mathematical framework. Some data for the transport of water and C1‐C7 alcohol vapors in unmodified Matrimid is provided in this work for comparison to EDA crosslinked Matrimid, however more complete datasets for the penetrant transport properties in unmodified Matrimid can be found in our previous work …”

Drug release kinetics of pH‐responsive microgels of different glass‐transition temperatures

“…The conventional technique used to determine the concentration of drugs released of nanoparticles is by dialysis or centrifugation, and the drug concentration is then determined by UV‐spectrophotometry or high‐performance liquid chromatography . A better and more accurate method is the use of drug selective electrode (DSE), where large amounts of data can be acquired, making the fitting of nonlinear Berens and Hopfenberg kinetic model possible …”