Anionic surfactant aggregation with (Hydroxypropyl)cellulose in the presence of added salt

Journal of the Brazilian Chemical Society

Ricardo M. Martins¹  Carolina A. Da Silva¹  Cristiane M. Becker¹  Dimitrios Samios¹  Marcelo Christoff¹  Clara I. D. Bica¹ 

[1] ,Universidade Federal do Rio Grande do Sul Instituto de Química Porto Alegre RS ,Brazil

关键词: bile salt;    cholate;    anionic surfactant;    (hydroxypropyl)cellulose;    light scattering;   

DOI  :  10.1590/S0103-50532006000500019

来源: SciELO

【 摘 要 】

The aggregation of different anionic surfactants in dilute aqueous solutions of (hydroxypropyl)cellulose (HPC) under moderate ionic strength (NaCl 0.1 mol L-1) was studied. The surfactants were sodium cholate (CS), sodium deoxycholate (DC) and sodium dodecylsulphate (SDS). By fluorescence probing, the critical aggregate concentration (C1) decreased for SDS and DC in comparison to the critical micelle concentration (CMC) whereas it increased for CS at 298 K. The relative viscosity reached a maximum for SDS/HPC but remained constant for CS/HPC and DC/HPC. By light scattering, cloud points were verified to increase. By dynamic light scattering, it was concluded that, at low surfactant contents, the fast mode of HPC is related to surfactant/HPC aggregates and shorter HPC chains; at high contents, to free micelles. The slow mode is linked to interchain polymer-surfactant complexes and HPC clusters. For the bile salts/ HPC systems, the mechanism of aggregation may occur in two steps.

【 授权许可】

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