Mesoporous silica can be formed with amphiphilic molecules acting as structure-directing templates in dilute systems. The templating properties of five related triblock copolymers, (EO) x −(PO) y −(EO) x (Pluronic L101, P103, P104, P105, and F108), have been investigated regarding the length of the EO blocks as well as the temperature of the synthesis. It was found that the number of EO units is essential in determining which silica mesophase is obtained. Lamellar structure is obtained with short EO chains (4 units); hexagonal structure, with medium length EO chains (17−37 units); and cubic structure, with long EO chains (132 units). The hydrophobicity of the (EO) x −(PO) y −(EO) x polymer is strongly affected by the temperature. This is to some extent reflected in the silica mesostructure formed; a multilamellar vesicle morphology can be obtained at elevated synthesis temperatures. Also, the temperature has an influence on particle size.

PIUS K. KIPKEMBOI, and ALLAN J. EASTEAL. Can. J. Chem. 72, 1937Chem. 72, (1994. The density and shear viscosity of mixtures of tert-butyl alcohol (BuOH) and tert-butylamine (TBA) with water have been determined for various temperatures (288 to 318 K for H20 + BuOH and 288 to 308K for H20 + TBA) over the whole composition range. Excess molar volumes and apparent molar volumes of the components of each system were calculated from the density data. In both systems the apparent molar volume of the organic component passes through a minimum in the water-rich region. Both systems exhibit large negative excess molar volumes which are essentially independent of temperature at all compositions. The two systems show pronounced maxima in their shear viscosity isotherms. Chem. 72, 1937Chem. 72, (1994. On a determint les densites et les viscosites de cisaillement de melanges d'alcool tert-butylique (BuOH) et de tert-butylamine (TBA) avec de I'eau, sur l'ensemble des compositions possibles et B diverses temptratures (allant de 288 K B 318 Kj pour H20 + BuOH et de 288 K B 308 pour H20 + TBA). Utilisant les donnkes de densite, on a calculk les volumes molaires en excbs et les volumes molaires apparents des composants de chaque systkme. Dans les deux systkmes, le volume molaire apparent du composant organique passe par un minimum dans la region riche en eau. Les deux systbmes presentes des volumes molaires en excbs largement negatifs qui sont essentiellement independants de la temperature, B toutes les compositions. Les deux systbmes prtsents des maxima importants dans leurs isothermes de viscosite de cisaillement.[Traduit par la redaction]

The empirical solvent polarity parameters ENR and ET for the solvatochromic compounds Nile Red (1) and pyridinium-N-phenoxide betaine (2), respectively, have been determined as a function of composition for water+t -butyl alcohol and water+t-butylamine binary mixtures, over the whole composition range at 298 K. For both systems the two parameters vary with composition in a strongly non-linear fashion, and the polarity of the mixture decreases with increasing proportion of the organic cosolvent. The non-linear variation of the polarity parameters is attributed to water-cosolvent hydrophobic interactions at low cosolvent contents, and hydrogen-bonding interactions at higher cosolvent contents. Permittivity and refractive index have also been measured at 298 K for both systems, and both properties are strongly non-linear functions of composition.

Raman and FT-IR absorption spectra of t-butyl alcohol and t-butylamine pure components have been recorded in the liquid state in the region of 400-4000 cm -1 . The data obtained have been used to propose complete vibrational assignments for each of the liquid component and the structural features are discussed. Additionally, the Raman and infrared spectra of the binary liquid mixtures for the t-butyl alcohol/t-butylamine system have also been recorded. The variations in frequency shifts, intensities and line widths are discussed with a view to understanding the origin of such variations.

The search for alternative, biodegradable, and sustainable raw materials to replace finite petrochemicals is an area of great interest. Triglycerides obtained from oilseed crops are such potential raw materials. In this study, sesame oil was trans-esterified to sesame fatty methyl esters (SEFAMEs) that were used as precursors in the synthesis of sesame fatty methyl esters sulfonate (SEFAMESO) surfactant. SEFAME and SEFAMESO surfactants were characterized by high-performance liquid chromatography–mass spectrometry (HPLC-MS), 1H NMR, and Fourier transform infrared (FTIR) spectra. HPLC-MS, 1H NMR, and FTIR spectra indicated successful trans-esterification and conversion of SEFAMEs to SEFAMESO. Solution properties of the SEFAMESO surfactant including hydrophilic–lipophilic balance (HLB) value, Krafft point, foam-ability, critical micelle concentration (CMC), counterion degree of binding and thermodynamic parameters such as ΔG°mic, ΔH°mic, ΔS°mic, ΔH°mic,* and T C were evaluated. The CMC values of SEFAMESO at 298.15 K were relatively lower than that of the sodium dodecyl sulfate (SDS) standard, and these values decreased to a minimum at 303.15 K and then increased with an increase in temperature. ΔG°mic values were negative indicating a spontaneous micellization process. ΔH°mic and ΔS°mic values revealed that micellization was entropy-driven at low temperatures and both entropy- and enthalpy-driven at high temperatures. ΔH°mic,* values were negative suggesting formation of stable micelles. The evaluated properties revealed the potential application of the synthesized surfactant as a cleansing agent.