Efficient synthesis strategy of folate-modified carboxymethyl chitosan/CaCO hybrid nanospheres and their drug-carrying and sustained release properties.

Folate-modified carboxymethyl chitosan (FCMC) was made by folate acid as targeted group and attaching folate to carboxymethyl chitosan, and then, targeted FCMC/CaCO hybrid nanosphere were formed by self-assembly of calcium carbonate in FCMC solution. The physicochemical properties of the nanospheres were investigated by Fourier transform infrared spectroscopy, X-ray diffraction analysis, Brunauer-Emmett-Teller measurement and thermogravimetric analysis (TGA). The results showed that the FCMC/CaCO hybrid nanospheres were composed of calcite, vaterite and polysaccharides, and the content of organic compounds was 12.

Adsorption behavior of norfloxacin and site energy distribution based on the Dubinin-Astakhov isotherm.

Concerns about the water resources contaminated by fluoroquinolone antibiotics have prompted research on effective and efficient treatment technologies. In this work, adsorbents based on barley straw were characterized on morphology, surface functional groups, and charge states for the adsorption of norfloxacin, a representative of fluoroquinolone antibiotics, from aqueous solutions. The effects of solution pH were studied, and high norfloxacin adsorption capacities of pretreated barley straw were achieved in a wide pH range (2.

Analyses of Levofloxacin Adsorption on Pretreated Barley Straw with Respect to Temperature: Kinetics, π-π Electron-Donor-Acceptor Interaction and Site Energy Distribution.

Levofloxacin, representative of an important class of fluoroquinolone antibiotics, has been considered to be one of the emerging pollutants in various water sources. In this paper, adsorption of levofloxacin from artificial contaminated water was done by pretreated barley straw adsorbent obtained from raw barley straw after modification by HPO impregnation and microwave heating. The adsorption kinetics was investigated at various temperatures and levofloxacin concentrations, and the activation energy was determined.

Preparation of monodisperse calcium alginate microcapsules via internal gelation in microfluidic-generated double emulsions.

Monodisperse hollow and core-shell calcium alginate microcapsules are successfully prepared via internal gelation in microfluidic-generated double emulsions. Microfluidic emulsification is introduced to generate monodisperse oil-in-water-in-oil (O/W/O) double emulsion templates, which contain Na-alginate, CaCO3 nanoparticles, and photoacid generator in the middle aqueous phase, for synthesizing Ca-alginate microcapsules. The internal gelation of the aqueous middle layer of O/W/O double emulsions is induced by crosslinking alginate polymers with Ca(2+) ions that are released from CaCO3 nanoparticles upon UV exposure of the photoacid generator.

Study on protein conformation and adsorption behaviors in nanodiamond particle-protein complexes.

In the present research, the conformation of bovine serum albumin (BSA) in the nanodiamond particle (ND)-BSA complex was studied by Fourier transform infrared spectroscopy, fluorescence spectroscopy, UV-vis spectroscopy, and circular dichroism spectroscopy. The spectroscopic study revealed that most BSA structural features could be preserved in the complex though the BSA underwent conformational changes in the complex due to ND-BSA interaction. In addition, BSA adsorption isotherms and zeta-potential measurements were employed to investigate the pH dependence of the ND-BSA interaction.

Phase transition behaviors of poly(N-isopropylacrylamide) microgels induced by tannic acid.

Effects of tannic acid (TA) on the phase transition behaviors of monodisperse poly(N-isopropylacrylamide) (PNIPAM) microgels in aqueous solutions are systematically investigated. Monodisperse PNIPAM microgels are prepared through a microfluidic approach. The isothermal phase transition behaviors of PNIPAM microgels induced by TA in aqueous solutions are studied at 25 degrees C.

Biosorption of nickel with barley straw.

Wastewater containing nickel sulphate generated from a nickel plating industry is of great concern. In the present work, biosorption of nickel by barley straw from nickel sulphate solution was investigated. Nickel uptake at room temperature (23+/-0.

Biosorption of arsenic (V) with acid-washed crab shells.

Highly toxic arsenate occurs naturally in some well water as well as in industrial wastewaters. Removal of arsenate (As(V)) by biosorption with acid-washed crab shells (AWCS) is very sensitive to solution pH. It greatly increased when the solution pH was lowered from 3.

Preparation and characterization of novel cationic pH-responsive poly(N,N'-dimethylamino ethyl methacrylate) microgels.

Novel monodisperse cationic pH-responsive microgels were successfully prepared by dispersion polymerization in ethanol/water mixture using N,N'-dimethylamino ethyl methacrylate (DMAEMA) as the monomer, poly(vinyl pyrrolidone) (PVP) as the steric stabilizer and N,N'-methylenebisacrylamide (MBA) as the cross-linker. The effects of various polymerization parameters, such as medium polarity, concentration of cross-linker, concentration of monomer, and concentration and molecular weight of stabilizer on the final diameter and monodispersity of poly(N,N'-dimethylamino ethyl methacrylate) (PDMAEMA) microgels were systematically studied. The pH-responsive characteristics of PDMAEMA microgels were also investigated.