Interaction of (Hydroxypropylmethyl)cellulose with Anionic Surfactants

Abstract

The aggregation process between (hydroxypropylmethyl)cellulose (HPMC 0.20% m/m) and three anionic surfactants namely sodium cholate (CS), sodium deoxycholate (DC) and sodium dodecylsulphate (SDS), in aqueous dilute solutions, was investigated by fluorescence, electrical conductivity, dynamic light scattering (DLS) and small angle X‐ray scattering (SAXS) techniques. Through fluorescence, the critical micelle concentration (CMC) and critical aggregation concentration (CAC) of the systems were obtained in good agreement with those obtained from conductivity. Also by means of conductivity measurements, once the experiments were undertaken at four temperatures, the thermodynamic parameters of the micellization process were calculated. From DLS, the relaxation time distribution functions were analyzed by REPES Routine, revealing that the surfactants bind to the polymer before CAC as well as the formation of free micelles at high surfactant content. The SAXS technique confirmed the existence of such free micelles.

Effect of Surfactant Tail Length on the Hydroxypropyl Cellulose-Mediated Premicellar Aggregation of Sodium n-Alkyl Sulfate Surfactants

“…sulfate (anionic, SDS), ,,,, carboxylate (anionic, e.g. sodium cholate), , benzyl sulfonate (anionic, dodecyl benzyl sulfonate), , imidazolium (cationic, 1-decyl-3-methylimidazolium chloride), trialkyl-ammonium (cationic, e.g., cetyltrimethylammonium bromide). , These studies infer that an attractive interaction between HPC and ionic-surfactant increases its cloud point temperature, solution viscosification, reduced counterion binding, and overall negative enthalpy change. , On the other hand, an increase in surfactant tail-length (or number of carbon atoms, n c ) enhances PS stability, growth rate, and HPC-surfactant binding cooperativity. ,,, All these results collectively propose that during PS formation charge–dipole interaction play a dominant role; however, short-range hydrophobic forces also play a meaningful role in the overall free energy change. Moreover, earlier studies ,,, have revealed that anionic surfactants, specifically those having sulfate headgroup, make a stronger interaction with HPC than the cationic ones.…”

“…sodium cholate), 25,32 benzyl sulfonate (anionic, dodecyl benzyl sulfonate), 23,33 1-decyl-3-methylimidazolium chloride), 5 trialkyl-ammonium (cationic, e.g., cetyltrimethylammonium bromide). 16,19 These studies infer that an attractive interaction between HPC and ionic-surfactant increases its cloud point temperature, 16 solution viscosification, 16 reduced counterion binding, 36 and overall negative enthalpy change. 5,25 On the other hand, an increase in surfactant tail-length (or number of carbon atoms, n c ) enhances PS stability, growth rate, 34 and HPC-surfactant binding cooperativity.…”

Phase Behavior of Nonionic Polymer Hydroxypropylmethyl Cellulose: Effect of Gemini and Single-Chain Surfactants on the Energetics at the Cloud Point

“…Additionally, these structural elements are, in general, erratically distributed along the polymer chain, and the substituents may consist of shorter or longer chains, giving rise to a varying degree of hydrophobicity . The interactions of such complex structures with ionic surfactants can give the system extraordinary properties. − Effects of various surfactants, viz., cationic, anionic, and nonionic, on the cloud point of cellulose ethers have been studied. ,− Whereas studies with anionic surfactant sodium dodecyl sulfate are extensive, those including cationic as well as nonionic surfactant systems are relatively fewer. Drummond et al, in a comparative study of the interaction of surfactants (anionic, cationic, and nonionic) with hydroxypropyl cellulose (HPC), had shown that anionic surfactants displayed much stronger affinity for HPC as compared to the cationic surfactants, while nonionic surfactants did not influence T CP of the polymer.…”

“…17 The interactions of such complex structures with ionic surfactants can give the system extraordinary properties. [18][19][20][21][22][23][24] Effects of various surfactants, viz., cationic, anionic, and nonionic, on the cloud point of cellulose ethers have been studied. 18,[25][26][27][28][29][30][31][32][33][34][35][36][37][38] Whereas studies with anionic surfactant sodium dodecyl sulfate are extensive, those including cationic as well as nonionic surfactant systems are relatively fewer.…”

Preparation of marigold (Calendula officinalis L.) extract using carbon dioxide under pressure and its microencapsulation in the polymer?surfactant system

“…Ispitivanja interakcije HPMC i nekih anjonskih PAM rađeno je i primenom konduktometrije, fluorescencije i metode dinamičkog rasipanja svetla (dinamic light scattering) [55]. Nađeno je da su cac i cmc određene primenom fluorescencije u saglasnosti sa vrednostima koje su određene konduktometrijskim titracijama.…”