Volume 43, Issue 3

In different type water, the hydrolysis of δ-modification layered sodium disilicate (δ-Na 2 Si 2 O 5 ) was investigated by employing XRD, FT-IR, SEM chemical analysis and residual solid yield. δ-Na 2 Si 2 O 5 was transported to another layered sodium silicate-kanemite (NaHSi 2 O 5 ·3H 2 O with cation exchange ability) in distilled water near the concentration in a magnitude, which is used by washing clothing. At the same concentration, δ-Na 2 Si 2 O 5 changed to a mixture of kanemite, Ca(OH) 2 and insoluble amorphous solid in water with Ca 2+ cations; a mixture of kanemite and insoluble amorphous solid in water with Mg 2+ cations. The evidence which δ-Na 2 Si 2 O 5 partly transport to another ion exchangeable single layer silicate (kanemite) indicated the existence of cation exchange on δ-Na 2 Si 2 O 5 . Another evidence which δ-Na 2 Si 2 O 5 partly dissolve and react with Ca 2+ and Mg 2+ cations indicated the existence to form precipitation. The experimental data suggested that the divalent cation binding process of δ-Na 2 Si 2 O 5 belongs to a mixture process with divalent cations exchange with Na + cation and precipitation in form of insoluble amorphous solid.

Polymeric surfactants were prepared from two beechwood glucuronoxylans, differing in the uronic acid content, molecular mass and solubility, by transesterification with vinyl laurate under homogeneous and heterogeneous reaction conditions and with methyl laurate under solvent-free conditions. The water-soluble derivatives exhibit significant emulsifying efficiency comparable to that of the commercial surfactants Tween 20 and Slovasol 245. The performance tests indicated good washing power and very low antiredeposition efficiency. Water-soluble glucuronoxylan laurates can be prepared from both xylan preparations with non-toxic esterification agents as well as under “solventfree” reaction conditions.

Surface properties of a series of aryl alkyl sulfonate surfactants were investigated. A strong structure-activity relationship was observed, depending on the variation of aromatic ring size in the hydrophobic chain. The results show that the size of aromatic ring, introduced to the carbon chain, affects their surface and thermodynamic properties. The values of critical micelle concentration (cmc), surface excess concentration (Γ max ), effectiveness (Π cmc ), to reduce surface tension of water, are decreased with increasing the aromatic ring size from phenyl to methylnaphthyl. While, the values of surface tension (γ cmc ) at cmc, Gibbs energy of micellization (ΔG mic °), and minimum area per molecule (A min ) are increased. Hence, the dominant factor of influencing on the area per molecule of aryl alkyl sulfonate surfactants would be the size of aryl alkyl chains.

The interfacial properties of a series of novel aqueous trisiloxane of the general formula Me 3 SiOSiMeROSiMe 3 [R=(CH 2 ) 3 N(CH 2 CH(OH)CH 2 (OCH 2 CH 2 ) n OCH 3 ) 2 n=1,2] were studied. The physicochemical parameters of these trisiloxane were discussed. These surfactants reduced the equilibrium surface tension of water to a minimum value of approximate 21∼22 mN/m at concentration levels of 10 −4 mol·L −1 .

A new family of dialkylaryl disulfonate Gemini-type anionic surfactant were synthesized based on the reaction of olefin sulfonic acid (C 14 AOS acid) with different aromatics. New synthesis route do not require the conventional alkylation unit and strong acid catalysts, and the resulting Gemini-type anionic surfactant differ from existing products by having the sulfonyl group attached to the alkyl chain rather than the aromatic ring. To optimizing reaction condition, a reliable double-wavelength spectrophotometric method and iodine value method were employed for measurement the conversion of the aromatics. The experimental has confirmed that the reaction time and temperature are mainly the factors of the effect of conversion. Under 150°C, C 14 AOS acid reacts with different aromatics for 4 or 5 hours to form dialkyaryl disulfonic acid, and dialkyaryl disulfonic acid was then neutralized to dialkyaryl disulfonate Gemini-type anionic surfactant. Some surface active property has been investigated too. The critical micelle concentration of ditetradecylbenzene disulfonate, ditetradecylnaphthalene disulfonate, ditetradecylmethylnaphthalene disulfonate, ditetradecylphenanthrene disulfonate, ditetradecyldiphenylether sulfonate, ditetradecyldiphenylmethane sulfonate and ditetradecylbenzophenone sulfonate were 1.7 × 10 −4 , 8.082 × 10 −6 , 2 × 10 −5 , 2.158 × 10 −3 , 5.0 × 10 −6 , 1.0 × 10 −5 and 1.33 × 10 −5 mol l −1 . Above datum showed the aromatics of the surfactant may effect on surface active property obviously. Among these, some dialkylaryl disulfonate gemini anionic surfactant have very higher surface active than conventional dodecylbenzene sulfonate and may be widely used in industry and household.