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We have been searching a new ion exchange material in the form of a fiber which could get large advantages over the conventional bead type. In this approach, an effective chelating fiber is prepared by the coupling of polyacrylonitrile (PAN) and ethylenediamine. A synthesized ion exchange fiber (poly(acrylo-amidino ethylene amine), PAEA) achieved 7.8 mequiv/g of adsorption capacity in a batch test. The coupling process and capacity were confirmed through FT-IR, acid−base neutralization titration, ICP, IC, and AAS. By means of verifying the bonding peaks (hydrogen and ionic bonding) under several pHs, molecular bonding between PAEA and ions (Cu2+ and CrO4 2-) was certified. Surface morphologies of chelating fibers and also after metal ion adsorption were examined by AFM. Compared with a batch test, the adsorption ability was low due to the diffusion path of ions in the dynamic test.

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To enhance the efficiency of heat transfer fluids, encapsulated phase change materials (PCMs) have been researched as the media for storing and release of a latent heat. The efficiency of thermal energy transportation and the durability of the PCM capsules are quite dependent on the physicochemical and mechanical properties of their shell. Herein, we have prepared the poly(2-hydroxyethyl methacrylate) (pHEMA) encapsulated paraffin-wax sphere as the PCM capsule with high encapsulation ratio, encapsulation efficiency, and thermal storage capability of 97.67, 97.33, and 99.65%, respectively. A hydrous PCM capsule exhibits improved thermal conductivity from ca. 0.26 to 0.47 W/(m·K) at 25 o C in comparison with a dry PCM capsule, and good durability in the melting-freezing cycle test. Our study demonstrates that the encapsulation of phase change material with the hydrous-flexible polymer shell is an effective strategy to enhance the thermal conductivity and durability of PCM capsules.