Dodecyl Amine Research Articles

Synthesis, characterization, antimicrobial and anti-biofilm activity of a new class of 11-bromoundecanoic acid-based betaines

Novel betaines were synthesized from esterquats, which in turn were obtained from the reaction of 11-bromo undecanoic acid, different alkyl amines, and methyl iodide. The synthesized betaines were characterized by fourier transform infrared, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and mass spectral analysis. These betaines were synthesized in four steps; in the first step, 11-bromo undecanoic acid was converted into methyl 11-bromoundecanoate followed by the synthesis of secondary amine monoester, and tertiary amine mono and diesters by the reaction of 11-bromoundecanoate with different aliphatic amines (hexyl, dodecyl, octadecyl, dioctyl, and dicyclohexyl amine). In the third step, the prepared secondary amine monoesters, tertiary amine mono, and diesters were converted into monoesterquats and diesterquats by reacting with methyl iodide. The resultant esterquats were converted into betaines by saponification reaction using LiOH.H2O in water and tetrahydrofuran. The synthesized compounds (5a–h) were studied for their antimicrobial activity. Some of the compounds showed good to moderate antibacterial activity with minimum inhibitory concentration values ranging between 3.9–31.2 µg mL−1 and antifungal activity with minimum inhibitory concentration values ranging between 7.8–62.4 µg mL−1. Further, some of the betaines also showed good anti-biofilm activity with IC50 values ranging between 2.1–25.3 µg mL−1 on the tested pathogenic microbial and fungal strains.

Dodecyl amine adsorption at different interfaces during bubble attachment/detachment at a silica surface

Dodecyl amine adsorption at different interfaces during bubble attachment/detachment at a silica surface

Effects of amphiphiles on the association state of the asphaltene and the viscosity of heavy oil

ABSTRACTThe effects of two types of amphiphiles on the association state of the asphaltene and the viscosity of heavy oil are systematically studied by testing the characteristics of viscosity and temperature, the centrifugal stability, and the conductivity. Experimental results show dodecylbenzene sulfonic acid (DDBSA) can enhance the stability of centrifugation of the asphaltene, increase the viscosity of the heavy oil, and improve the conductivity of the systems of heavy oil, amphiphile, and n-heptane. But the results obtained by the addition of dodecylamine (DA) are opposite to those of DDBSA. Due to the loose structure of the association body of the asphaltene, DDBSA causes a big association body to split into large number of small association bodies which influence more light weight compounds and increase the viscosity of the heavy oil; DA can compress the solvation layer and weaken the effect of solvation to decrease the viscosity of the heavy oil. The conclusions can provide certain guidance for the development of a new type of viscosity reducer with high efficiency.

Experimental investigation and DFT calculation of different amine/ammonium salts adsorption on kaolinite

The adsorption of four different amine/ammonium salts of DDA (Dodecyl amine), MDA (N-methyldodecyl amine), DMDA (N,N-dimethyldodecyl amine) and DTAC (Dodecyl trimethyl ammonium chloride) on kaolinite particles was investigated in the study through the measurement of contact angles, zeta potentials, aggregation observation, adsorption and sedimentation. The results show that different amine/ammonium salts can adsorb on the kaolinite surface to enhance the hydrophobicity and reduce the electronegativity of kaolinite particle surface, and thus induce a strong hydrophobic aggregation of kaolinite particles which promotes the settlement of kaolinite. To explore the adsorption mechanism of these four amine/ammonium salts on kaolinite surfaces, the adsorptions of DDA+, MDA+, DMDA+ and DTAC+ on kaolinite (001) surface and (001¯) surface are calculated with DFT (Density functional theory). The DFT calculation results indicate that different amine/ammonium cations can strongly adsorbed on kaolinite (001) surface and (001¯) surface by forming NH⋯O strong hydrogen bonds or CH⋯O weak hydrogen bonds, and there are strongly electrostatic attractions between different amine/ammonium cations and kaolinite surfaces. The main adsorption mechanism of amine/ammonium cations on kaolinite is hydrogen-bond interaction and electrostatic attraction.

Removal of fine quartz from coal-series kaolin by flotation

Coal-series kaolin (CSK) in Xuzhou, Jiangsu Province of Eastern China was characterized by chemical analyses, X-ray diffraction (XRD) and zeta potential measurement as well as by scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS). The authigenic ultrafine quartz grains (d90=15.8μm) closely associated with this CSK sample was the major impurity mineral, which cannot be separated from kaolin by screening and size classification process. This work investigated the separation of fine quartz from kaolin by flotation. Single mineral flotation tests indicated that effective separation of quartz from kaolin was possible with acidic pH value (pH=3), depressant of starch and collector of dodecyl amine (DDA). Rougher flotation tests of coal-series kaolin revealed that the SiO2/Al2O3 weight ratio of the concentrate was qualified for industrial applications in the presence of 160g/t starch and 100g/t DDA, at acidic pH pulp. A specially designed two-stage cleaner flotation flowsheet increased the concentrate recovery from 37.26% to 46.55% compared to a rougher flotation process.

Reverse froth flotation of magnesite ore by using (12-4-12) cationic gemini surfactant

The cationic gemini surfactant 1,4-bis(dodecyl-N,N-dimethylammoniumbromide)butane (BDDAB) was tested as a possible collector in the reverse froth flotation of magnesite ore. This novel type of collector was compared with its conventional monomeric equivalents: primary dodecylamine (DA) and tertiary dimethyldodecylamine (DDA). Electrokinetic measurements documented a strong effect of the synthesized gemini surfactant on the zeta potential of quartz. The effect of the three collectors declined in the following order: BDDAB>DA>DDA. Laboratory froth flotation tests confirmed an improved collecting ability of the gemini surfactant compared to both the conventional collectors. The desilication efficiency declined in the following order: BDDAB>DA>DDA. The results obtained with the lowest concentration of the gemini surfactant were better in terms of SiO2 content than those obtained with four times higher dosages of the conventional collectors.

Influences of interfacial adhesion on gas barrier property of functionalized graphene oxide/ultra-high-molecular-weight polyethylene composites with segregated structure

The segregated graphene oxide(GO)/ultra-high-molecular-weight polyethylene (UHMWPE) composite films with various interfacial adhesion property were prepared by mechanical blending method from UHMWPE, GO, dodecyl amine (DA) functionalized graphene oxide(DA–GO) or uniform DA–GO/high density polyethylene (DA–GO/HDPE) powder. The results of XRD and XPS indicated that DA chain was successfully grafted onto GO sheets via a chemical method, which enhanced the interfacial adhesion between UHMWPE particles and GO sheets. The characterizations of POM and SEM proved that good segregated structure was only obtained in DA–GO/UHMWPE or DA–GO/HDPE/UHMWPE composite. Strong interfacial adhesion between fillers and matrix exhibits positive effect on gas barrier property. Compared to the GO/UHMWPE composite film, dramatic decrease in O2 permeability coefficient by 42.2 and 48.1%, from 15.4 × 10−14 to 8.9 × 10−14 and 8.0 × 10−14 cm3 cm cm−2 s−1 Pa−1, is achieved upon the addition of only 0.5 wt% fillers, respectively. The DSC results demonstrated that the enhanced gas barrier performance was ascribed to the strong interfacial adhesion between DA–GO/HDPE and UHWMPE matrix, rather than the crystallinity of UHWMPE matrix. Additionally, the decrease in UHMWPE particle size might be conducive to improving the gas barrier property of composite films due to the formation of more isolation layers perpendicular to the film plane.

Facile Preparation of Biocomposite from Prawn Shell Derived Chitosan and Kaolinite-Rich Locally Available Clay

A novel composite material was prepared from prawn shell derived chitosan (CHT) and locally available kaolinite-rich modified Bijoypur clay (MC) using a facile technique in which dilute acetic acid was used as a solvent for dissolving chitosan and composite fabrication whereas distilled water was used for preparing the clay dispersion. Bijoypur clay mainly consists of kaolinite clay mineral and it was modified with the dodecyl amine to make it organophilic. Morphology and properties of the composites (different weight ratio of MC and CHT) have been studied and compared with those of pure CHT and MC. Purification and modification of Bijoypur clay were investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier transformed infrared spectroscopy (FTIR) analyses. The fabrication of CHT-MC composites was confirmed by FTIR analysis. Thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC) were used to investigate the thermal stability of the composites. It was observed that dispersed clay improves the thermal stability and enhances the hardness of the matrix systematically with the increase of clay loading. In this study, a better insolubility in both acidic and alkaline media of the composites is also observed compared to pure chitosan.

Synthesis, characterization and thermal studies of silver nanoparticles-β-cyclodextrin inclusion complexes modified with (2E)-3-{3-[(Z)-naphthalen-1-yldiazenyl] phenyl} prop-2-enoic acid

A photoactive system, (2E)-3-{3-[(Z)-naphthalen-1-yldiazenyl] phenyl} prop-2-enoic acid, was synthesized and incorporated on to beta-cyclodextrin (β-CD) core through esterification of the hydroxyl groups of β-CD with the free carboxyl moiety of the chromophoric system by DCC coupling. The silver nanoparticle was synthesized by the reduction reaction executed on silver acetate in presence of dodecyl amine. The silver nano particles were dispersed in β-CD aggregates modified with photoactive system by phase transfer mechanism. The products were characterized by elemental analysis, melting point determination, UV–visible, FT-IR and NMR (1H and 13C) spectral methods and SEM and TGA-DTG thermal studies. The thermal studies shows that the silver nanoparticle dispersed functionally modified beta cyclodextrin exhibited enhanced thermal stability compared to the functionalised β-CD.

Surface activity, micellization and solubilization of cationic gemini surfactant-conventional surfactants mixed systems

In this paper, we have studied the mixed surfactant systems containing a cationic gemini surfactant N,N′-bis(dimethyldodecyl)-1,2-pentanediammonium dibromide (12-5-12) with several differently charged surfactants (cationic/anionic/non-ionic/zwitterionic) by using surface tension, small angle neutron scattering (SANS) under standard condition. All the surfactants have same dodecyl chain but different in polar head group viz. Sodium dodecyl trioxyethylene sulphate (SDES)(anionic), dodecyl trimethyl ammonium bromide (DTAB) (cationic), 3-[dodecyldimethyl ammonio] propane sulphonate (C12-PS)(zwitterionic), hexaethylene glycol monododecyl ether (C12E6)(non-ionic) and dimethyl dodecyl amine oxide (DMDAO) (cationic-non-ionic). The Clint, Rubingh, Maeda and Rosen approaches were employed to determine various parameters like critical micelles concentration (CMC), surface excess concentration (Гmax), surface pressure at CMC (πCMC), minimum area per molecule (Amin) etc. as well as thermodynamic parameters. Solubilization of some polycyclic aromatic hydrocarbons (PAHs) have done in single as well as in mixed surfactant systems. Order of solubilization capacity of PAHs compounds are different in pure/mixed surfactant micelles. The solubilization efficiency towards naphthalene, anthracene, and pyrene were measured and the molar solubilization ratio (MSR), deviation ratio (R) and micelle-water partition coefficient (km) were evaluated for single and mixed systems.

Investigation of the performance of several chemical additives on inhibition of asphaltene precipitation

ABSTRACTThe inhibition effects of several chemical additives on asphaltene precipitation were investigated by the microscopic method. The additives consist of a synthesized deep eutectic solvent (SDES), a commercial inhibitor, and three surfactants, namely lauric acid, octyl phenol, and dodecyl amine. The results showed the octyl phenol with 500 mg/L concentration is similar to commercial inhibitor and later SDES had the maximum effects on delaying the asphaltene precipitation onset point. The mean particle size of asphaltene using octyl phenol, SDES, lauric acid, and dodecyl amine decreased about 55%, 41%, 24%, and 18%, respectively, compared to the oil sample without any chemical additives.

Synthesis of porous Al pillared montmorillonite after pre-intercalation with dodecylamine: textural and thermal properties

Al pillared montmorillonites (Al-PILM) were synthesized by the reaction of Na+-montmorillonite (Na+-Mt) and hydroxy-Al cation after pre-intercalation with dodecylamine (DA) under different drying methods and calcination temperatures. The results showed that Al-PILM dried at room temperature was more crystalline and had larger c-axis spacing, d(001), BET specific surface area (SBET) and microporous volume, compared to those by common air-blast drying or vacuum drying and the superiority in the above properties of the drying methods is as follows: air drying > air-blast drying > vacuum drying. This suggests that natural air drying at room temperature favored the formation of more ordered pillar formation. It was also found that the pre-intercalation of DA had important influence on the physicochemical properties of Al-PILM. When the amount of pre-intercalated DA was 1/2 CEC of Na+-Mt, c-axis spacing, d(001), SBET and microporous volume of Al-PILM were increased and larger than those prepared without pre-intercalation of DA and the former sample had a more regularly ordered pillar distribution due probably to the reduced pillar density in the montmorillonite interlayers. The DA pre-intercalated PILMs were stable at a larger range of temperatures. With the increase of calcination temperature, the interlayer spacing d(001) value decreased, and the SBET and microporous volume increased firstly and then decreased. During calcination, the pre-intercalated DA was removed and the hydroxyl-Al cation was converted into the rigid Al2O3 pillars, which resulted in decreased pillar size between Mt layers followed by porosity improvement of Al-PILM.

Enhanced Mechanical Properties of Functionalized Graphene Oxide/linear Low Density Polyethylene Composites Prepared by Melt Mixing

Graphene oxide (GO) was concurrently reduced and functionalized using long alkyl chain dodecyl amine (DA). The DA functionalized GO (DA-G) was assumed to disperse homogenously in linear low density polyethylene (LLDPE). Subsequently, DA-G was used to fabricate DA-G/LLDPE composites by melt mixing technique. Fourier transform infrared spectra analysis was performed to ascertain the simultaneous reduction and functionlization of GO. Field emission scanning electron microscopy analysis was performed to ensure the homogenous distribution and dispersion of DA-G in LLDPE matrix. The enhanced storage modulus value of the composites validates the homogenous dispersion of DA-G and its good interfacial interaction with LLDPE matrix. An increased in tensile strength value by ~ 64% also confirms the generation of good interface between the two constituents, through which efficient load transfer is possible. However, no significant improvement in glass transition temperature was observed. This simple technique of fabricating LLDPE composites following industrially viable melt mixing procedure could be realizable to developed mechanically strong graphene based LLDPE composites for future applications.

Effect of Dodecyal Amine Functionalized Graphene on the Mechanical and Thermal Properties of Epoxy‐Based Composites

Simultaneous surface functionalization and reduction of graphene oxide (GO) was achieved by using dodecyl amine (DA) as surface modifying agent. The DA modified reduced GO (DA‐G) was used for subsequent preparation of DA‐G/epoxy composites by solution mixing. Fourier transform infrared spectroscopy analysis, X‐ray diffraction (XRD) and electrical conductivity measurements were conducted to establish the concurrent functionalization and reduction of GO. The effect of DA‐G on the epoxy composites at 0 to 0.75 wt% loadings was studied by investigating its static and dynamical mechanical properties. XRD study was performed to verify the dispersion of DA‐G in the epoxy polymer. Field emission scanning electron microscopy was used to investigate the fracture surface morphology of the composites and Transmission electron microscopy was employed to further confirm the dispersion of DA‐G in the matrix. It was found that the tensile strength of the composite was increased by 38.8% with the addition of 0.5 wt% of DA‐G. The good adhesion/interaction between DA‐G and epoxy resulted in the increase of storage modulus; however, glass transition temperature (Tg) value of the composites shifted to lower temperature in comparison to the neat epoxy. Thermogravimetric analysis showed small decrease in onset degradation temperature for the composites as compared to neat epoxy except for the composites containing 0.75 wt% of DA‐G. POLYM. ENG. SCI., 56:1221–1228, 2016. © 2016 Society of Plastics Engineers

In situ embedding of ultra-fine nickel oxide nanoparticles in HMS with enhanced catalytic activities of styrene epoxidation

In this paper, a new templating assemble route (S0M+I−) was proposed to construct a nickel-based mesoporous silica catalyst. During this method, the neutral surfactant dodecyl amine was used as a special agent for both capturing the metal ions and structure-directing of the mesoporous silica. Based on the templating assemble route, metal cations were highly enriched in the interface of micelles and silicate wall by the physiochemical interaction among the surfactant (S0), metal cations (M+, Ni2+) and silicate oligomers (I−). Besides, instead of original hydrogen-bonding, the addition of metal cations in the assemble process made the interaction between micelles and silicate oligomers improved significantly through the counterion-mediated interaction. According to these effects, highly-dispersed, ultra-fine and accessible nickel oxide nanoparticles (NPs) were in situ produced and embedded in the channels and the exposed level of the active sites on these NPs would reach to the highest. Moreover, as expected, the synthesized catalyst exhibited superior catalytic activities for the epoxidation of styrene.

Cr(VI) adsorption by montmorillonite nanocomposites

Various montmorillonite (Mt) nanocomposite adsorbents were prepared with Al13 cations, dodecyl trimethyl ammonium chloride (DTAC) or dodecyl amine (DA) and characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and BET surface area and pore size analyses. The adsorption of hexavalent chromium, Cr(VI) onto various Mt nanocomposites as a function of adsorbent dosage, initial Cr(VI) concentration, contact time and solution pH was investigated. The results showed that the obtained nanocomposites had large basal spacing and good porous structure, and the specific surface areas followed the order: OH-Al-Mt>DA-Al-Mt>DTAC-Al-Mt>Na+-Mt>DTAC-Mt>DA-Mt. The removal efficiency of Cr(VI) ions increased with increasing the adsorbent dosage and contact time, but decreased with increasing initial Cr(VI) concentration, as expected. The adsorption of Cr(VI) was highly pH-dependent and the maximum removal efficiency of Cr(VI) was found in the acid environment. The adsorption equilibrium time was 2h and the adsorption kinetic data of Cr(VI) on various adsorbents were well described by the pseudo-second-order kinetics model, which indicated that the adsorption reaction of Cr(VI) ions with the adsorbents was mainly due to chemical adsorption. Both the Langmuir model and Freundlich model fitted the equilibrium data well, which suggested that the Cr(VI) adsorption onto various adsorbents was both as monolayer and on heterogeneous surface conditions. The adsorption results indicated that among all the adsorbents used in this experiment, the dodecyl amine and Al13 cations composited with Mt (DA-Al-Mt) was the most effective for removing Cr(VI) from wastewater.

Effects of physical crosslinks on the photoresponse of epoxy-based polymers

The influence of physical crosslinks on the photoinduced anisotropy in epoxy linear polymers with azobenzene and alkyl side groups was studied. Two series of linear epoxy-based polymers were synthesized by reaction between diglycidyl ether of bisphenol A (DGEBA), Disperse Orange-3 (DO3), and dodecylamine (DA). Two strategies of synthesis were employed in order to analyse the optical behavior of the polymers with their architecture. As a result, a polymer with randomly distributed amine groups (one-step polymerization), and another with both amines forming blocks (two-step polymerization) were synthesized. The experimental evidence derived from different techniques confirmed that isothermal annealing at several temperatures produced association of DA alkyl chains. The rate of this physical gelation process could be varied with the annealing temperature and the polymer architecture. The association strength of the alkyl chains was higher for the block polymer. The rate of the physical gelation process increased as the annealing temperature did. UV–visible spectroscopy showed interactions between the azo groups and aggregated alkyl chains only for the polymer prepared in two steps. For the same chromophore content, block polymers yielded higher birefringence than random ones did. The increment in the information stored (remnant birefringence) for annealed samples was considerable only for block polymers. This study demonstrates the importance of the polymer architecture and the presence of domains of alkyl chains on its potential photo responsiveness.

Synthesis and characterization of graphene and functionalized graphene via chemical and thermal treatment methods

Graphene oxide was chemically synthesized, functionalized with dodecyl amine and then reduced. The graphene oxide was also thermally reduced to obtain graphene. Different analyses were employed to structural characterization of the materials.

Phase Inversion Emulsification and Enhancement of Physical Properties for Cationic Emulsified Asphalt

In this work, the emulsified asphalt with high phase stability and storage stability was prepared by using phase inversion emulsification and the surfactant mixed with cationic and nonionic surfactants. It was found that the asphalt together with Span 20, nonionic surfactant and DDA (Dimethyl Dodecyl Amine), cationic surfactant showed the most stable phase. The phase stability of the emulsified asphalt, therefore, was investigated through the particle size with mixed surfactant content, rheology behavior and Zeta potential value; the particle size decreased with the increase of the mixed surfactant content but the viscosity increased. The shear thinning behaviors and the Zeta potential value with 50 mV~60 mV were shown, which was found to be considered stable. In addition, SBR latex(Styrene-butadiene-rubber) and water dispersed Epoxy (EPD) were used to enhance the physical properties of the emulsified asphalt. The swelling and adhesion features of the emulsified asphalt were also studied with <TEX>$CaCO_3$</TEX>, Silica, and Montmorillonite (MMT). It was shown that the addition of SBR latex and MMT can be another way to improve the physical properties of the emulsified asphalt in that the lowest swelling feature was found.

Flotation separation of marine microalgae from aqueous medium

Harvesting of oleaginous marine microalgae by dewatering is an important step for cost-effective algal biomass feedstock production. This paper reports separation of marine microalgae (Tetraselmis sp. M8) from aqueous medium by froth flotation using various collectors (surfactants) with equal carbon chain length, such as dodecyl pyridinium chloride (DPC), N-dodecylpropane-1,3-diamine hydrochloride (DN2), dodecyl amine hydrochloride (DAH), and sodium dodecyl sulphate (SDS), at different pHs. Algal hydrophobicity, froth stability, and surfactant precipitation were characterised. The laboratory-scale mechanical flotation tests showed that at natural pH 9.5 and a lower pH, DPC outperformed DAH, DN2 and SDS in separating Tetraselmis sp. M8 from seawater. DPC was capable of rendering the microalgae hydrophobic, producing metastable froth, and dissolving readily in water, which are all desirable features of a collector for flotation separation of microalgae from water. Use of DPC at 15 ppm in pilot-scale Jameson cell flotation tests for M8 after outdoor cultivation led to a 23-fold increase in algal concentration with over 99% algal recovery. (C) 2015 Elsevier B.V. All rights reserved.