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Poly (aspartic acid sodium salt) (PAspNa) was evaluated for its potential as a novel draw solute in forward osmosis (FO). The inherent advantages of PAspNa, such as good water solubility, high osmotic pressure, and nontoxicity, were first examined through a series of physicochemical analyses and atomic-scale molecular dynamics simulations. Then, lab-scale FO tests were performed to evaluate its suitability in practical processes. Compared to other conventional inorganic solutes, PAspNa showed comparable water flux but significantly lower reverse solute flux, demonstrating its suitability as a draw solute. Moreover, fouling experiments using synthetic wastewater as a feed solution demonstrated that PAspNa reversely flowed to the feed side reduced inorganic scaling on the membrane active layer. The recyclability of PAspNa was studied using both nanofiltration (NF) and membrane distillation (MD) processes, and the results exhibited its ease of recovery. This research reported the feasibility and applicability of FO-NF or FO-MD processes using PAspNa for wastewater reclamation and brackish water desalination. [ABSTRACT FROM AUTHOR]

Abstract: Biodegradable polymeric microneedles were developed as a method for achieving sustained transdermal drug release. These microneedles have potential as a patient-friendly substitute for conventional sustained release methods. However, they have limitations related to the difficulty of achieving separation of the needles into the skin. We demonstrated that microneedle separation into the skin was mediated by hydrogel swelling in response to contact with body fluid after the needles were inserted into the skin. The hydrogel microparticles were synthesized by an emulsification method using poly-N-isopropylacrylamide (PNIPAAm). The microneedles were fabricated by micromolding poly-lactic-co-glycolic acid (PLGA) after filling the cavities of the mold with the hydrogel microparticles. The failure of microneedle tips caused by hydrogel swelling was studied in regard to contact with water, insertion of microneedles into porcine cadaver skin in vitro, stress–strain behavior, and insertion into the back skin of a hairless mouse in vivo. The drug delivery property of the hydrogel particles was investigated qualitatively by inserting polymer microneedles into porcine cadaver skin in vitro, and the sustained release property of PLGA microneedles containing hydrogel microparticles was studied quantitatively using the Franz cell model. The hydrogel particles absorbed water quickly, resulting in the cracking of the microneedles due to the difference in volume expansion between the needle matrix polymer and the hydrogel particles. The swollen particles caused the microneedles to totally breakdown, leaving the microneedle tips in the porcine cadaver skin in vitro and in the hairless mouse skin in vivo. Model drugs encapsulated in biodegradable polymer microneedles and hydrogel microparticles were successfully delivered by releasing microneedles into the skin. [Copyright &y& Elsevier]

• The new synthesis route of siloxane-based materials is presented. • The key factor of hardness and modulus of hard coating material is both Mw and PDI. • The hard coating layer is studied with nanoindentation analysis. • 2-step sol-gel synthesized hard coating improved surface hardness by 32 %. Flexible but still hard coating materials have been paid attention for applications in flexible electronic devices, as efforts to substitute glasses. However, there have been little approaches to find out control parameters determining their flexibility and hardness. Here, we present reaction-controlled polysilsesquioxane (PSQ) resins with improved flexibility and hardness. In this study, the effects of various reaction conditions on the molecular weight of the PSQ resins are investigated in terms of reaction time, and absence of byproducts, accompanying the analysis of mechanical properties of the corresponding films using nanoindentation. With the reaction-controlled PSQ resins by removing byproducts such as alcohols, the molecular weight could be increased up to 44 % compared to PSQ containing the byproducts. The surface hardness and modulus of hard coating films are also enhanced by 32 % and 13 % compared to that from original PSQ resin, respectively. Finally, we demonstrate folding reliability for 100 k bending cycles at various bending radii of 6 to 1 mm that shows improved warpage property with less irreversible deformation upon the folding test. [ABSTRACT FROM AUTHOR]