A series of X-type alkyl sulfonate Gemini surfactants (XC n , n = 6, 8, 10) was synthesized by a simple method. The chemical structures of the prepared compounds were confirmed by 1 H NMR, 13 C NMR, ESI-MS and Elementary analysis. The surface activity and thermodynamic properties of micellization of the X-type alkyl sulfonate Gemini surfactants were compared with sodium dodecylsulfate by means of surface tension. The properties of XC n are superior to those of SDS such as the c CMC and CMC of XC 10 are 26.3 mN/m and 0.2 mmol/L respectively. The adsorption isotherms for XC n were established by fitting the pre-CMC surface tension data with a quadratic function. The thermodynamic parameters of micellization (DG m , DH m , DS m ) derived from electrical conductivity indicate that the micellization of XC n is entropy-driven.

The laser monitoring observation technique is proposed to measure the solubility and supersolubility of RDX in different proportion and temperature for the antisolvent crystallization. Experimental determination of the solubilities curve and the metastable zone widths (MSZWs) are presented. Knowledge of the solubility curve and the stability of the solution in the vicinity of the equilibrium point, as indicated by the MSZW, is essential to the successful development, optimization, and scale-up of a crystallization process. Then the solubility characteristic in acetone is correlated by Apelblat empirical equation and the solubility characteristic and the supersolubility characteristic in binary mixed solvents of acetone-water are correlated by (CNIBS)/Redlich-Kister equation, all the RMSDs of models are less than 0.001.