Effect Of Chain Length Compatibility Research Articles

Effect of Chain Length Compatibility of Alcohols on Muscovite Flotation by Dodecyl Amine

A portion of dodecyl amine (DDA) in a muscovite flotation system was replaced with alcohols with different carbon-chain lengths. These alcohols included octanol (OCT); decanol (DEC); dodecanol (DOD); and tetradecanol (TER). The muscovite adsorption behavior of the mixed DDA and alcohol systems were investigated through zeta potential; contact angle; and adsorption quantity tests. Single-mineral flotation tests showed that the muscovite-collecting power of the mixed DDA/alcohol (OCT, DEC, or DOD) system was stronger than that of the pure DDA system. The muscovite-collecting power of the collector systems decreased in the following order: DDA/DEC > DDA/OCT > DDA/DEC > DDA > DDA/TER. Zeta potential and contact angle analysis indicated that when combined with DDA; alcohols physically adsorbed on the surfaces of muscovite. This behavior improved the hydrophobicity of muscovite. Furthermore, adsorption analysis revealed that synergy between DDA and alcohol enhanced the adsorption of alcohol on muscovite. DDA has a dominant role in synergistic adsorption; whereas alcohol has a supporting role. Among all tested alcohols; DDA and DOD exhibit the highest synergetic adsorption effect because of their similar carbon-chain lengths. This similarity promotes the formation of a compact adsorption layer on the muscovite surface.

Study on the effect of chain-length compatibility of mixed anionic–cationic surfactants on the cloud-point extraction of selected organophosphorus pesticides

The chain-length compatibility of mixed anionic-cationic surfactants was investigated for the extraction of organophosphorus pesticides (OPPs). Cationic surfactants with different chain lengths (n = 12 and 16) were mixed with sodium dodecyl sulfate (SDS; n = 12) for the mixed anionic-cationic surfactants-based extraction. Six OPPs were studied including azinphos-methyl, parathion-methyl, fenitrothion, diazinon, chlorpyrifos, and prothiophos. Reversed-phase high-performance liquid chromatography was used for the determination of the studied OPPs. The extraction was performed using mixtures of SDS and cationic surfactants including dodecyltrimethyl ammonium bromide or dodecyltrimethylammonium bromide (DTAB; n = 12) and cetyltrimethyl ammonium bromide or cetyltrimethyl ammonium bromide (CTAB; n = 16). The parameters affecting the extraction efficiencies of two extraction systems were studied and discussed. The optimum condition for SDS-DTAB was 15 mmol L(-1) SDS and 1 mmol L(-1) DTAB in the presence of 15% (w/v) sodium chloride (NaCl). Meanwhile, the condition for SDS-CTAB was 10 mmol L(-1) SDS and 1.0 mmol L(-1) CTAB with 10% (w/v) NaCl. Under the optimum conditions, the extraction efficiency of SDS-DTAB (66-85%) was slightly higher than that of SDS-CTAB (61-82%). In addition, the SDS-DTAB system also gave greater enrichment factor than SDS-CTAB for all the studied OPPs. This result may be due to the compatibility of chain length between SDS and DTAB. The extraction using SDS-DTAB was successfully applied to determine OPPs in fruit samples (i.e., pomelo, apple, and pineapple). No contamination by the studied OPPs in samples was observed. Good accuracy with recoveries ranging from 77 to 105% was obtained. Low limits of detection were in the range of 0.003-0.01 mg kg(-1) which are below the MRLs established by EU-MRLs for the OPPs residues in fruit samples.

Effect of Chain Length Compatibility between Surfactants and Co-Surfactants on Corrosion Inhibition of Steel

Corrosion inhibition effect of cationic surfactants, DTAB (Dodecyl Three methyl Ammonium Bromide) and TTAB (Tetradecyl Three methyl Ammonium Bromide) on low carbon steel was studied using weight loss, Open circuit potentional (OCP) and Electrochemical Impedance Spectroscopy (EIS) measurements. The effect of chain length compatibility on corrosion inhabitancy of surfactant and co-surfactant was investigated by C7OH (1-heptanol), C12OH (1-dodecanol) and C15OH (1-pentadecanol) as nonionic co-surfactants in acidic media at different concentrations of DTAB and TTAB. Data represented that the corrosion rate decreased by increasing concentration of DTAB and TTAB, independently. The effect of chain length compatibility on surfactant behavior was discussed. Decreasing of corrosion rate for DTAB+C12OH was more pronounced than other mixtures.

Electrochemical effect of Gemini Surfactant and Co-Surfactants on Corrosion Inhibition of Steel in Acid Medium

The effect of chain length compatibility on corrosion the inhibition effect of mixed inhibitor systems of cationic gemini surfactant, l,4-butan-bis (dodecyl dimethyl ammonium bromide) (designated as 12-4-12) with nonionic co-surfactants, C7OH (1-heptanol), C12OH (1-dodecanol) and C15OH (1-pentadecanol), on low carbon steel in acid medium was studied using weight loss, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. The data demonstrated that the corrosion rate decreased by increasing surfactant concentration. In addition, less chain length difference causes more compatibility and inhibition on behavior of surfactant and co-surfactant mixture. Inhibition efficiency for C12OH + gemini surfactant was increased compared to the other mixtures explored.

Effect of Chain Length Compatibility between Surfactants and Co-Surfactants on Corrosion Inhibition of Steel

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Effect of nonionic co-surfactants on corrosion inhibition effect of cationic gemini surfactant

The effect of chain length compatibility on corrosion inhibition effect of mixed inhibitor systems of cationic gemini surfactant (l,3-butan-bis(dodecyl dimethyl ammonium bromide) (designated as 12-4-12)), nonionic co-surfactants (C 7OH (1-heptanol), C 12OH (1-dodecanol) and C 15OH (1-pentadecanol)) on low carbon steel in acidic medium was studied using weight loss, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. Data represented that the corrosion rate decreased by increasing surfactant concentration. In addition, less chain length difference causes more compatibility and inhibition efficiency on behavior of surfactant and co-surfactant mixture. Increasing of inhibition efficiency for C 12OH + gemini surfactant was more than other mixtures.

The chain length influence of cationic surfactant and role of nonionic co-surfactants on controlling the corrosion rate of steel in acidic media

The corrosion inhibition effect of cationic surfactants, DTAB (Dodecyl Trimethyl Ammonium Bromide) and TTAB (Tetradecyl Trimethyl Ammonium Bromide), on low carbon steel was studied using weight loss, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements. The effect of chain length compatibility on corrosion inhabitancy of surfactant and co-surfactant was investigated by C 7OH (1-heptanol), C 12OH (1-dodecanol) and C 15OH (1-pentadecanol) as nonionic co-surfactants in acidic media at different concentrations of DTAB and TTAB. Data represented that the corrosion rate decreased by increasing concentration of DTAB and TTAB, independently. The effect of chain length compatibility on surfactant behavior was discussed. Decreasing of corrosion rate for DTAB + C 12OH was more pronounced than other mixtures.

Effects of surfactants on the transport properties of redox species through Nafion ® membranes

Previous research in our group has employed tetraalkylammonium bromides to alter the micellar structure of Nafion ® membranes to affect flux of redox species through the membrane. However, research by Patist et al. has shown that maximum micellar stability occurs when the chain lengths of the both the main micellar component and the surfactant are the same in sodium dodecyl sulfate micelles (SDS). When considering the steric hindrance of large, spherical ammonium salts and the effect of chain length compatibility on micellar stability, it was determined that n-alkyltrimethylammonium and n-alkyltriethylammonium surfactants may be more favorable in altering the pore structure. This research focuses on mixture-casting Nafion ® with ammonium-based surfactants in order to form more stable Nafion ® membranes with larger pore structures and a less acidic environment that will be more biocompatible with entrapping dehydrogenase enzymes within the membrane. n-Alkyltriethylammonium and n-alkyltrimethylammonium surfactants decreased the number of available exchange sites to proton (proton exchange capacity) of the membrane and they altered the transport of redox species through the membrane. Phenyltrimethylammonium bromide treated Nafion ® membranes and triethylhexylammonium bromide treated Nafion ® membranes were found to successfully immobilize dehydrogenase enzymes while maintaining enzyme activity.

Effect of Chain Length Compatibility on Micellar Stability in Sodium Dodecyl Sulfate/Alkyltrimethylammonium Bromide Solutions

The effect of chain length compatibility on the micellar stability was investigated for mixtures of sodium dodecyl sulfate (SDS) and alkyltrimethylammonium bromides (CnTAB, n = 8, 10, 12, 14, 16) at a 20/1 molar ratio. It was observed that the surface properties of surfactant solutions were influenced by the chain length compatibility of the surfactant molecules. The slow micellar relaxation time (τ2), which directly correlates to the micellar stability, was determined using the pressure-jump technique. The addition of CnTAB to SDS solutions results in a significant increase in the relaxation time compared to SDS alone, showing a maximum for the SDS/C12TAB system. The high micellar stability results in minimum surface tension, maximum surface viscosity, maximum micellar lifetime, maximum foam stability, and minimum foamability. The higher micellar stability as observed for SDS/C12TAB is attributed to both the chain length compatibility and the Coulombic interaction of the surfactant head groups, resulting...

The Effect of Chain Length Compatibility on Molecular Area, Intermolecular Spacing, Dispersion Energies and Evaporation Resistance of Mixed Monolayers

AbstractUsing mixed monolayers of alkyl alcohols, it was established that the unequal chain lengths cause an expansion in the area/molecule in mixed monolayers. Assuming the cross‐sectional area of molecules to be circles, it was shown that a difference of two methylene groups between the two components of the mixed monolayer causes an increase in the intermolecular spacing of about 0.05 A. The small increase in intermolecular spacing strikingly decreases the resistance of mixed monolayers to evaporation of water. The surface viscosity was found to be maximum when the chain‐lengths of the components were equal. The dispersion energy between alcohol molecules in the mixed monolayer was calculated using Salem's approach. It was found that a small increase in intermolecular spacing (0.05Å) can decrease the dispersion energy by 6.7 kJ/mol. The magnitude of this decrease is about 1/4 of the energy of a hydrogen bond. It was further shown that the small increase in intermolecular spacing, decreases the melting point of mixed crystals by about 9°C. The chainlength compatibility of mixed surfactants also influences the bubble size, bubble stability, emulsion stability, lubrication, contact angle and wettability. In summary, using the monolayer approach, it was experimentally shown that a small change of 0.05 Å in intermolecular spacing, brought about by a difference of 2 methylene groups between the two surfactant molecules, can strikingly influence the dispersion energy between the molecules. The small change in dispersion energy influences the characteristics of many engineering processes such as bubbles, foams, emulsions, lubrication and wettability.