To illuminate the interactions in N-[(2-hydroxyl)-propyl-3-trimethyl ammonium] chitosan chloride (HTCC)/sodium carboxymethyl cellulose (CMC) based films, the film-forming solutions were studied by rheology, and HTCC/CMC based films were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The HTCC/CMC based film-forming solutions with glycerol (polyvinyl alcohol (PVA) and anthocyanin) showed shear-thinning behavior. The apparent viscosity of the HTCC/CMC/glycerol (PVA and anthocyanin) film-forming solutions decreased slower than that of HTCC/CMC film-forming solution, due to the electrostatic interaction between HTCC and CMC, and hydrogen bonding interaction between the two biomacromolecules and glycerol, PVA and anthocyanin, which resulted in the formation of three-dimensional networks. The anthocyanin with rigid molecular structure formed different three-dimensional matrix with HTCC/CMC, resulted in viscosity dominated film-forming solution. The pH affected the electrostatic interaction between HTCC, CMC, and anthocyanin through neutralizing –COO⁻ groups, and temperature showed a synergistic effect on both electrostatic interaction and hydrogen bonding. The inter-molecular interactions resulted in the red-shift of typical absorption peaks, and the increase of initial decomposition temperature and decomposition enthalpy of HTCC/CMC based films. The homogenous and smooth surface, and the compact texture of HTCC/CMC based films confirmed the intermolecular interaction between HTCC, CMC, and PVA (glycerol and anthocyanin). Interactions in N-[(2-hydroxyl)-propyl-3-trimethyl ammonium] chitosan chloride and sodium carboxymethyl cellulose based films The HTCC/CMC/glycerol (PVA, anthocyanin) blend solutions show shear-thinning behavior, and the strong interaction between the molecules resists the decrease of viscosity.

Chitosan has potential applications in many fields, due to its biocompatibility, biodegradability and reproducibility. However, the insolubility in water restricts its wide application. In order to expand the application of chitosan in the delivery of oil-soluble drugs and improve the efficacy of oil-soluble drugs, N-Glycidyltrimethyl ammonium chloride-modified chitosan (GTA-m-CS) and N,N-Dimethyl-N-dodecyl-N-(1,2-epoxy propyl) ammonium chloride (DDEAC), a kind of reactive surfactant, were synthesized and characterized by FTIR, NMR and XRD methods. The interactions between GTA-m-CS and DDEAC was studied by surface tension, viscosity, conductivity and fluorescence methods. The parameters, including equilibrium surface tension, critical micelle concentrations of DDEAC with different GTA-m-CS concentration, critical aggregation concentration of DDEAC, the amount of DDEAC adsorbed on GTA-m-CS, pc₂₀ and π_cmc were obtained from the surface tension curves. The influence of temperature on the above parameters were evaluated. The degree of counterion binding to micelle and the thermodynamic parameters of the system were calculated from the conductivity curves. According to the change of conductivity with temperature, the thermodynamic parameters of micellar formation were calculated. The aggregation number of DDEAC molecules in GTA-m-CS/DDEAC aggregates were calculated from steady-state fluorescence data. Based on the experimental results, the interaction models between GTA-m-CS and DDEAC were proposed. The GTA-m-CS/DDEAC aggregates could be used as curcumin carries, and achieved sustained release.

A series of epoxy-functionalized quaternary ammonium surfactants consisting of different alkyl chains (C₁₀–C₁₈) were synthesized. Their aggregation behaviors in aqueous solution, as well as antibacterial activity and reactivity were investigated. The cmc, γ_cmc, π_cmc, pc₂₀ and cmc/c₂₀ suggested that the presence of epoxy group increased the surface activity of ADEAC. This is ascribed to the hydrogen bonding effect between the adjacent hydrophilic groups. The surface activity increased with the increase of hydrocarbon chain length. The thermodynamic parameters indicated that the micellization process was entropy-driven at high temperature, and enthalpy-driven at low temperature. The activation energy of conductance and micelle aggregation number were also calculated. The antibacterial activity of ADEAC against Gram-negative bacteria was stronger than that for Gram-positive ones, and N-dodecyl-N,N-dimethyl-N-(1,2-epoxy propyl) ammonium chloride showed the most effective antibacterial activity. The synthesis of N-hexadecyl-N,N-dimethyl-N-(1,2-epoxy propyl) ammonium chloride (HDEAC) modified chitosan demonstrated the reactivity of HDEAC.