Synthesis of texture-excellent mesoporous alumina using PEG1000 as structure-directing agent

By varying concentration of PEG1000 as a structure-directing agent,mesoporous alumina with excellent textural properties was synthesized.The prepared mesoporous alumina displays high thermal stability,as shown by its textural properties at different calcination temperatures of 600-850 °C.Characterization by SEM and TEM revealed that the added PEG surfactant induced the formation of petal-like alumina.XRD results clarified that all samples were amorphous and their peaks were around the peaks of γ-alumina.N_2 adsorption-desorption analysis showed that the prepared mesoporous alumina,if with PEG1000 in hydrolysis of aluminum isopropoxide,had excellent textural properties with large specific surface area,high pore volume and suitable pore size.The petal-like structure existing in the alumina samples improved their textural parameters,and the role and influential mechanism of PEG1000 were analyzed.

Cellulose Nanocrystals-Coated Polylactide(PLA) Microspheres Obtained via a Pickering Emulsion Approach

In order to prepare cellulose nanocrystals( CNCs)-coated polylactide( PLA) microspheres for the use of drug delivery and tissue engineering,a Pickering emulsion route was applied. The stable Pickering emulsions were prepared using CNCs as efficient stabilizers without any additional surfactant. The microspheres were successfully fabricated after volatilization of the solvent. What's more,the size of microspheres could be controlled by fabrication parameters.

A Surfactant-stable Bacillus pumilus K9 α-Keratinase and Its Potential Application in Detergent Industry

An a-keratinase producing strain was isolated with wool as the sole carbon and nitrogen source and identified as Bacilluspumilus K9. The major amino acids liberated from the keratin degradation of wool by B. pumilus K9 were glutamic acid and leucine. The a-keratinase was purified to electrophoretic homogeneity with a molecular weight of 32000. The purified enzyme exhibits an optimum activity at 60 ℃ and pH=9.0. It was stable at pH values between 8 and 11. Bacillas pumilus keratinase displays a high activity towards casein, keratin, wool and feather, which indicates its wide application range. The keratinase was completely inhibited by phenylmethyl-sulfonyl fluoride（PMSF） and β-mercaptoethanol, and moderately inhibited by ethylemediamine-tetraacetic acid（EDTA）, suggesting it is a metallo-cysteine keratinase. This enzyme could remain stable that could even be promoted in the presence of surfactants, including sodium dodecyl sulfate（SDS）, Tween and Triton. And Tween 40 and Triton X-100 could substantially enhance the activity of the enzyme by 54% and 35%, respectively. It may indicate the prominent feature of the keratinase to tolerate surfactants. The enzymatic properties distinguish this keratinase from others in the literature. Furthermore, this enzyme is extremely stable in the presence of a commercially available detergent with 1% concentration. Detergents ARIEL, Bluemoon and WhiteCat can enhance the activity of the keratinase by 43.56%, 15.22%, and 22.48%, respectively.

Molecularly imprinted open porous membranes made from Pickering W/O HIPEs for selective adsorption and separation of methyl 4-hydroxybenzoate

In this study, novel molecularly imprinted open porous membranes（MIOPMs） were prepared using the Pickering HIPEs template method and molecular imprinting technology for selective adsorption and separation of methyl 4-hydroxybenzoate（M4HB）. The template M4 HB, functional monomers,crosslinker and plastifier 2-ethylhexyl acrylate（2-EHA） were contained in the oil phase. Hydrophobic silica nanoparticles（HNP-SiO2） were employed as a stabilizer to establish stable W/O Pickering HIPEs with nonionic surfactant sorbitantrioleate（Span 85）. The results of SEM and FTIR indicated that the optimal MIOPMs were prepared successfully and possessed open and interconnecting pores. Then, the MIOPMs were used as sorbents for M4 HB. The correlation coefficient（R^2） values for the Langmuir–Freundlich isotherm model and pseudo-second-order kinetic model fitting to the adsorption equilibrium and kinetic data respectively were all higher than 0.95. The maximum adsorption capacity and the time of rapid adsorption for MIOPM4 were 4.146 mg g^-1 and 100 min, respectively. In addition, the permeability separation factor of MIOPMs for M4 HB compared to a structurally related analog methyl2-hydroxybenzoate（M2HB） could reach 3.122.