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In this study, a novel electrospun nanofibrous composite was synthesized from polyacrylonitrile (PAN) and well-dispersed oxide nanoparticles containing Ti and Ag (PAN-TA). The nanoparticles incorporated into the nanofibers can endow the composite with photocatalytic and antimicrobial ability. The morphologies and structure of the nanofibers were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Controlled experiments were carried out with the effects of chemical modification, solution pH, temperature, dosage, contact time, and initial concentration of the dye. The methylene blue (MB) dye was completely removed within 20 min at room temperature 25 o C with high maximum retention capacity of 155.4 mg g -1 . Moreover, equilibrium data and kinetics data indicated that the dye adsorption agreed well with the Langmuir isotherm model and pseudo-second order model, respectively. In addition, the nanofibers could be easily separated from dye solution and showed high reusability for numerous repeat cycles, thus indicating good application prospects for the wastewater treatment.

Solid lipid nanoparticles (SLNs) have attracted increasing attention as colloidal drug carriers due to theirs advantages including low toxicity, drug targeting and modified release. However, undesired particle aggregation in aqueous dispersions would limit the applicability of SLNs for drug delivery. The purpose of the present article is to investigate the aggregation behavior of the SLNs and quantitatively evaluate how the concentration of NaCl and F68 affect the stability of the SLNs. The early stage aggregation kinetics of the SLNs was investigated over a wide range of NaCl concentrations by employing dynamic light scattering (DLS). In the presence of the NaCl, aggregation kinetics of the SLNs exhibited reaction-limited (slow) and diffusion-limited (fast) regimes. These results indicated that the aggregation behavior of these new nanoparticles can be well explained by the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The critical coagulation concentration (CCC) of SLNs containing 0.0%, 0.1%, 0.5%, 2.0%, and 4.0% of Poloxamer 188 (F68) was 416, 328, 519, 607, and 602 mM, respectively, suggesting that the F68 influences the aggregation behavior of the SLNs. F68 made the SLNs more sensitive to the electrolyte when its concentration is low (0.1%), the bush of the polymer F68 has a bridging effect that accelerated the aggregation process of the SLNs. However, at the high concentration, F68 can provide the steric repulsion to the nanoparticles, which effectively stabilized the SLNs dispersions.

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