Preparation and characterization of the n-HA/PVA/CS porous composite hydrogel☆

In this paper,a new method combines chemical/physical crosslinking,and emulsification-foaming porogenic was adopted to prepare n-hydroxyapatite(n-HA)/polyvinyl alcohol(PVA)/chitosan(CS)porous composite hydrogel using artificial cornea scaffold materials.The fabricate conditions,including the type and amount of emulsification-foaming porogen,mixing time and speed etc.were researched.The results showed the optimal condition that the alkylphenol polyoxyethylene ether(OP)acted as emulsification-foaming porogen,with the ratio of WPVA/WOP as 3.75,and mixing 15 min with a stirring speed of 800 r·min-1.Additionally,the fabricated composite hydrogel scaffold materials possessed interconnected internal holes,a moisture content of above 65%,and tensile strength of above 6 MPa.In vitro cytotoxicity and acute systemic toxicity assay confirmed that the scaffolds did not show any cytotoxicity.The as-prepared hydrogel could be a promising candidate for artificial cornea scaffold material.

Fabrication and adsorption property of novel adsorbent for potential application to wastewater with Fe(Ⅲ) ions

The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spherical macroporous cellulose derivative adsorbent(PSMC).FT-IR and scanning electron microscope(SEM) were employed to characterize the adsorbents and Fe3+ ions served as model solute to evaluate the adsorption property of the adsorbents.The experimental results show that the amount of porogenic agents and the value of pH have obvious influence on adsorption capacity of the adsorbents.The data of adsorption kinetic and isotherm display that the adsorbents possess excellent equilibrium adsorption capacity(348.94 mg/g) and have a bright prospect and considerable potential in the treatment of Fe3+ ions in wastewater.

Using PEG as Progen to Preparate Chitosan Scaffold for Tissue Engineering

Tissue engineering basically made up growing the relevant cell in vitro and extracellular matrix. A major goal of tissue engineering is to preparate porous three dimension scaffold for cell proliferate, migrate, differention and to form the structure of desirable tissue and organ. In this study, the effects of various content and macromolecular weight of PEG to chitosan were investigated and evaluated. The pore morphology of chitosan was controlled by changing the concentration and macromolecular weight of PEG. Chitosan porous scaffold has interconecting porosity. The pore morphology can be controlled with varying PEG concentration and macromolecular weight. The pore size is between 10～50 urn, the degree of swelling in water is 85.70 % .

Macroporous Hydrogels Prepared by Ice Templating: Developments and Challenges

Macroporous hydrogels are water-swollen polymer networks with porous structures beyond the mesh size.They provide high specific surface areas and hieratical mass transfer channels which are desired for emerging applications including cell culturing,bio-separation,and drug delivery.A variety of approaches have been developed to fabricate macroporous hydrogels,including gas foaming,porogen templating,phase separation,3D printing,etc.Alternatively,ice templating utilizes the crystallization of water as the porogenation mechanism which doesn't need the leaching of porogens.

Hierarchically Porous Biomass Carbon Derived from Orange Peel for Atomically Dispersed Co-N-C Sites Toward Advanced Oxygen Reduction Reaction

Use of the transition-metal single atomsupported by carbon is an innovative technique that enhances the electrocatalytic behavior of the oxygen reduction reaction(ORR)for Zn-air batteries(ZABs).Yet,building such catalysts with stable and efficient electron/mass transport pathways,as well as high catalytic activity and stability remains a critical challenge.Here,we develop a hierarchically porous biomass carbon to anchor atomically dispersed Co atoms,simultaneously addressing the active sites’emergence and stability,and electron/mass transit.The optimum catalyst achieves fabulous electrocatalytic behavior with a half-wave potential of 0.82 V for ORR.More impressively,the ZAB with its well-tailored catalyst exhibits extraordinary combined performance,including a high zenith power density of 139.89mW·cm^(−2),outstanding specific capacity,and remarkable rate durability.This rational design strategy can be applied to create high-efficiency and inexpensive electrocatalysts for sustainable energy conversion and storage devices.