The properties of Pluronic F127 aqueous solutions with the variation of concentration and temperature were studied by cyclic voltammetry at the presence of sodium bromide. By this method, the relationship between the peak currents of electroactive probe, 2, 2, 6, 6-tetramethyl-1-piperidinyloxy (TEMPO), and the viscosity of F127 aqueous solutions within some temperature ranges was discussed, and the diffusion coefficient (D) of TEMPO in F127 aqueous solutions at various concentrations under different temperatures was determined. The critical micellar temperature (CMT) of F127 aqueous solution at various concentrations can be obtained from the curve of the peak current ip against the square root of reciprocal viscosity (1/η)1/2 and from the curve of logarithm diffusion coefficient (logD) of TEMPO as a function of reciprocal temperature (1/T). All the results are in good agreement with the results from 1H NMR measurements. Besides, the thermodynamic parameters such as diffusion activation energy (ED) and hydrodynamic radius (RH) can be also obtained from the above two curves. A new method was introduced to determine the CMT of copolymer systems, which is simple, quick, and accurate.

Carboxymethyl-polyaminate chitosan (DETA-CMCHS), a novel kind of amphoteric chitosan derivative, was prepared and characterized by elemental analysis, and by IR and 1H NMR spectroscopy. The adsorption behavior of Reactive Blue (RB2) on DETA-CMCHS was also studied. Results showed that the maximum value of adsorption capacity was 1185.71 mg/g at pH 3. The adsorption kinetic behavior was fitted with a second-order reaction rate equation. The adsorption was an exothermic, irreversible and entropy-reduced process according to thermodynamic parameters, such as standard Gibbs free-energy change, enthalpy change, and entropy change, all of which were calculated from adsorption equilibrium data.

Chitosan/chondroitin sulfate complex microcapsules were prepared to encapsulate the anti-cancer drug 5-fluorouracil (5-Fu) by emulsion-chemical crosslinking method. The microcapsules were characterized by Fourier transform infrared spectroscopy (IR), scanning electron microscopy (SEM) in conjunction with energy dispersive X-ray spectrometry (EDS), and laser diffraction particle size analysis. The in vitro drug release behavior of 5-Fu from the microcapsules was studied by UV–visible spectrophotometry. Results showed that the microcapsules were in spherical form with diameter mostly in the range of 20–60 μm. Result of EDS showed that 5-Fu was in the internal core of the microcapsules. The IR spectrum indicated that electrostatic interactions exit between chitosan and chondroitin sulfate, with the sulfate group and free carboxyl group reacted with the amino groups of chitosan. The release kinetic experiments showed that the release performance of the microcapsules was influenced by the amount of crosslinking reagent, drug loading and the pH of the release medium.

A new kind of amphiphilic derivatives of chitosan, (2-hydroxypropyl-3-butoxy) propyl-succinyl-chitosan (HBP-SCCHS) were synthesized by chemical modification of chitosan. The chemical structures of the chitosan derivatives were characterized by FTIR, 1H NMR and elemental analysis. The surface and aggregate properties were studied by means of surface tension and fluorescence measurements. Results showed that HBP-SCCHS can concentrate on the surface to decrease the surface tension and can associate with hydrophobic chains to form aggregates in the solution. The abilities to decrease the surface tension and to form aggregates were promoted by increasing the DS of hydrophobic group and addition of salt.