The inter-micellar interaction enthalpies of DTAB/TX100 mixed micelles and their structural transitions

Abstract

The heats of mixing for a series of DTAB/TX100 mixed surfactant aqueous solutions were measured by flow-mixing calorimetry and isothermal titration calorimetry (ITC) at 298.15 K and 85 kPa, which were used to calculate the inter-micellar interaction enthalpies (-ΔH). The signs of -ΔH for pure DTAB and TX100 micellar systems were contrary to the inter-micellar interaction parameters reported for the same systems in the literature, suggesting that these interaction parameters might have a Gibbs free energy character dominated by entropy changes. It was found that the inter-micellar interaction enthalpies varied with the total surfactant concentration and the mixed ratio of the two surfactants, and characterized different structures of the mixed micelles. These phenomena were discussed based on the effects of structural water around the micellar interface, the hydration of counterions, and the repulsive Coulombic interaction.

Polyaniline inside the pores of high surface area mesoporous silicon as composite electrode material for supercapacitors

“…[47][48][49][50][51][52] The mixture of pores can be due to the reason that the surfactant TX-100 can form both spherical and oblate micelles depending upon the arrangement of oxyethylene chains inside the micelles. [53][54][55] The pores of SBA are of the size $5 nm, and the material shows a narrow pore size distribution, see Fig. 6.…”

Self‐assembly and solution behavior of cationic surfactants in water‐trifluoroethanol environment: An experimental and theoretical approach

“…[1][2][3][4][5][6][7][8][9]. Such work has become signi cant as they enhance the surfactant performance in solution which enable them to be used widely as lubricants, in cleaning processes, enhanced oil recovery, drag reduction, drug delivery and hierarchical structure materials, etc [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Amongst the varied additives reported, study addressing alcohols has turned up to be very interesting.…”

“…Literature studies have presented the significance of the solute–solute and solute–solvent interactions involved in the surfactant systems, thereby explaining the micellization mechanism, both in water and in the presence of different additives such as alcohols, amines, acids, drugs, salts, etc., (Kern et al, 1991; Davies et al, 2006; Krishnaswamy et al, 2005; Kuperkar et al, 2008; Kumar, Verma, et al, 2021; Kumar, Kaur, & Awasthi, 2021). Such approaches have grabbed a keen attention from the researchers as it improves the surfactant performance in the solution mileu, allowing them to be used widely in enhanced oil recovery, drug delivery, drag reduction, etc., (Agrawal et al, 2019; Ito et al, 2014; Kumar et al, 2020; Kumar & Rajeshwarrao, 2011; Pal et al, 2019; Wang et al, 2020; Yin et al, 2017). Among many additives that have been documented, research on alcohol has proven to be particularly interesting.…”