Papers by Keyword: Surface Activity

Abstract: A novel series of fatty betaines containing a pyrimidine ring with different alky chain lengths were synthesized by condensation of fatty N,N'-diphenylalkylamidines with a specific highly reactive malonic ester derivative under mild conditions. The chemical structures of products were characterized by common spectroscopic analyses (FTIR, mass spectra, ¹H NMR, and ¹³C NMR spectrometry). Equilibrium surface tension and conductivity as a function of concentration of dodecyl pyrimidinum betaine (betaine with a 12 -carbon alkyl chain) in ethanolic solutions were measured and the critical micelle concentration (CMC) was determined at 30 °C. The results showed that the critical micelle concentration (CMC) of dodecyl pyrimidinum betaine is 0.925 mmol/L and the corresponding surface tension (γ_CMC) is 25.38 mN/m respectively. These results revealed that the synthesized fatty pyrimidinium betaines are efficient amphoteric surfactants making them promising candidates for applications in a very large number of areas.

Abstract: The paper considers the possibility of using energy criteria (surface activity, free surface energy) to quantify the efficiency of a highly dispersed system consisting of fine particles of secondary concrete as a component of composite binder of the hydration type of hardening. Using the G.A. Zisman method, the value of the critical surface tension was determined for secondary concrete fractions with different degrees of dispersion, which gives an idea of the free surface energy of a surface area unit. Based on the experimental data for determining the specific surface area and critical surface tension, the free surface energy and surface activity of the studied concrete powder were calculated, which can serve as criteria for quantitative energy characteristics of raw materials for the production of composite binders. Calorimetric studies related to measurements of the thermal effects of the hydration reaction of highly dispersed samples of secondary concrete have shown that this process is exothermic, the enthalpy of hydration of which is comparable to a similar parameter for cement. It was experimentally shown that fine powders of secondary concrete are effective as components of a composite binder, but they need to be pre-activated to optimal parameters, one of which is surface activity. In addition, the symbasis of changes in surface activity, the specific heat of the hydration reaction of highly dispersed concrete fractions and the compressive strength of fine-grained concrete samples made by using a composite binder containing a highly dispersed fraction of secondary concrete was established.

Abstract: Four anionic maleic monoester carboxylate polymeric surfactants were synthesized by the reaction of maleic anhydride with linear alcohols of different chain length in the ratio of 1:1.1 under 80 °C. Then the intermediate products were neutralized by sodium hydroxide at 60 °C to produce the final monomers. The structures of products were confirmed by FTIR. The surface tension was measured at 45 °C and the thermodynamic parameters were calculated. The results show that the polymeric surfactants possess low critical micelle concentration (CMC), high adsorption affinities and good surface and interfacial activity.

Abstract: Cationic Gemini surfactant concentration, the inorganic salts added and the pH value of surface tension obtained cationic gemini surfactant critical micelle concentration is 0.4mmol / L;by adding three kinds of inorganic salts NaCl, MgCl2, and Na2SO4 ,which Na2SO4 has the greatest impact on surface tension, followed by MgCl2.The surface minimum tension of the pH ranged from 9 to 11 , indicating that the surface activity of cationic gemini surfactants achieved the highest.

Abstract: Cationic Gemini surfactant concentration, the inorganic salts added and the pH value of surface tension obtained cationic gemini surfactant critical micelle concentration is 0.4mmol / L;by adding three kinds of inorganic salts NaCl, MgCl2, and Na2SO4 ,which Na2SO4 has the greatest impact on surface tension, followed by MgCl2.The surface minimum tension of the pH ranged from 9 to 11 , indicating that the surface activity of cationic gemini surfactants achieved the highest.

Abstract: Chemical composition of larch bark residue after tannin extraction was analyzed and sulfonation reaction was proceeded on bark residue. Effects of sulfonation of bark chemical components on surface activity, dispersing property and fluidity of cement paste products were studied. Results showed that the main chemical compositions of bark residue after tannin extraction were phenolic acid and lignin, which were much higher than that of wood raw material. Hydrolysable tannin and condensed tannin also existed in bark residue. Lignosulfonate prepared from bark residue had better surface activity, dispersing property, the reason might be the existence of soluble tannin and phlobatannin, high fluidity of cement paste might come from the existence of soluble tannin and phenolic acids.

Abstract: Ethanediyl-N-hexadecyl-tri(sodium α-glycinate) (N-hexadecyl ED3A), which belongs to the chelating surfactants, was synthesized by three-step reactions in this study. The structure of the product was characterized by IR. The surface activity and the properties of N-hexadecyl ED3A as degumming agent were investigated. The IR spectra showed the characteristic bands corresponding to the stretching vibration of C-N, -COONa, and C-H groups. The critical micelle concentration (cmc) of N-hexadecyl ED3A was 0.249mmol•L-1, and the surface tension at the cmc (γcmc) of it was 33.03mN•m-1. This revealed that the surfactant had fairly low cmc and excellent surface activity. Lower dosage of N-hexadecyl ED3A showed as good result as the conventional soap in silk degumming process, and the degumming result was also excellent without adding the chelating dispersant.

Abstract: The novel anionic gemini surfactant, isodium salt of N, N’, N”- trilauroyl-diethylenetriamine diacetate(TDAD), was synthesized with ethylenediamine, sodium chloroacetate and lauroyl chloride by displacement reaction and acylation reaction. The results show that TDAD has fairly low critical micelle concentration (cmc) and high surface activity. The adsorption isotherm of TDAD at the interface of oil sand/aqueous solution is taken on “S” model, and the adsorption loss of TDAD is much lower than that of the traditional monomer sodium laurate (SL).

Abstract: Rosin is reputed as green petroleum because it is renewable, not expensive, and environmental friendly. China is rich in rosin resources. In this report, rosin was used as raw material to prepare rosinyl amine salt (RAS) surfactant. The optimal reaction conditions of RAS was modified rosin and dimethylamine mole ratio of 1:2, reaction temperature of 78 oC and reaction time of 2 h. The chemical structure of the product was identified by Fourier transform infrared spectroscopy (FTIR), electrospray ionization-mass spectrometry (ESI-MS) and 1H nuclear magnetic resonance (NMR) analysis. As a surfactant, it has a critical micellar concentration (CMC) of 7.07×10-5mol/L, a surface tension of 44.36 mN/m, an emulsification activity of 5min, a height of foam of 165 mm, and a foam stability of 143 mm.

Abstract: Silk peptide-based surfactants were synthesized from fatty acyl chloride and silk peptide using Schotten-Baumana method. The structure of the product was characterized by IR and amino acid analysis, and the surface activity of the product was tested. The IR spectra showed the characteristic bands corresponding to the stretching vibration of C=O, N-H, C-N and -COONa groups. The amino acid analysis indicated that there were many kinds of amino acid in the products, and the most ones were glycine and alanine, which made up nearly 95% of the total content of amino acid. The surface activity experiment results showed these surfactants had excellent surface activity. In the homologous compounds of surfactants, the critical micelle concentration (cmc) reduced and the trend of micelles formation increased with the hydrocarbon chain length increasing.