Dodecyltrimethylammonium Chloride Research Articles

Stabilization of natural gas foams using different surfactants at high pressure and high temperature conditions

AbstractNatural gas foam can be used for mobility control and channel blocking during natural gas injection for enhanced oil recovery, in which stable foams need to be used at high reservoir temperature, high pressure and high water salinity conditions in field applications. In this study, the performance of methane (CH4) foams stabilized by different types of surfactants was tested using a high pressure and high temperature foam meter for surfactant screening and selection, including anionic surfactant (sodium dodecyl sulfate), non‐anionic surfactant (alkyl polyglycoside), zwitterionic surfactant (dodecyl dimethyl betaine) and cationic surfactant (dodecyl trimethyl ammonium chloride), and the results show that CH4‐SDS foam has much better performance than that of the other three surfactants. The influences of gas types (CH4, N2, and CO2), surfactant concentration, temperature (up to 110°C), pressure (up to 12.0 MPa), and the presence of polymers as foam stabilizer on foam performance was also evaluated using SDS surfactant. The experimental results show that the stability of CH4 foam is better than that of CO2 foam, while N2 foam is the most stable, and CO2 foam has the largest foam volume, which can be attributed to the strong interactions between CO2 molecules with H2O. The foaming ability and foam stability increase with the increase of the SDS concentration up to 1.0 wt% (0.035 mol/L), but a further increase of the surfactant concentration has a negative effect. The high temperature can greatly reduce the stability of CH4‐SDS foam, while the foaming ability and foam stability can be significantly enhanced at high pressure. The addition of a small amount of polyacrylamide as a foam stabilizer can significantly increase the viscosity of the bulk solution and improve the foam stability, and the higher the molecular weight of the polymer, the higher viscosity of the foam liquid film, the better foam performance.

Comparative study on the use of three types of clay stabilizers in acidification

From the perspective of clay stability mechanism, inorganic salt clay stabilizers, surfactant clay stabilizers and polymer clay stabilizers were studied, aiming to optimize the clay stabilizer for acidizing. Firstly, PDMDAAC and CPAM were successfully prepared and characterized. Then, the performance of seven clay stabilizers, including NH4Cl, KCl, dodecyl trimethylammonium chloride (DTMA), cetyltrimethylammonium chloride (CTMA), amide Gemini quaternary ammonium salt (GSA), PDMDAAC and CPAM, were compared under different conditions. The results show that the 2% salt clay stabilizer can reach 90% of the anti-swelling rate. While 1% surfactant and polymer can reach 70% and 80% of the anti-swelling rate respectively. In addition, the salt clay stabilizer has great high-temperature resistance and the polymer clay stabilizer has good scour resistance. In contrast, the surfactant clay stabilizer has poor effect in acid environment owing to critical micelle concentration. The mechanism research shows that the electrostatic interaction of the cations ionized by inorganic salt and the negative ions in the clay stabilizes clay. Besides ionizing cations, surfactant clay stabilizer and polymer clay stabilizer prevent the external fluid from entering clay interlayer through the aggregation of hydrophobic groups and the formation of polymer film respectively.

Physical properties of deep eutectic solvents based on p-toluene sulfonic acid and employment as catalyst

This work studied the physical properties of three deep eutectic solvents (DESs) and their catalytic activity in the esterification of palmitic acid and ethanol. Three types of deep eutectic solvents (DESs) were successfully prepared using p-toluene sulfonic acid monohydrate (PTSA) as hydrogen bond donor (HBD) with dodecyl trimethyl ammonium chloride (DTAC), tetradecyl trimethyl ammonium chloride (TTAC) and octadecyl trimethyl ammonium chloride (OTAC) as hydrogen bond acceptor (HBA). The freezing points of DESs were measured in the range of 50%–80% HBD mole percentage, and the composition of DTAC-PTSA, TTAC-PTSA and OTAC-PTSA at the eutectic point (the lowest freezing points) was determined respectively (DES1, DES2 and DES3). The physical properties (density, refractive index, dynamic viscosity, conductivity and pH value) of DES1∼DES3 were studied respectively in the temperature range of 298.15 K to 343.15 K. The results showed that dynamic viscosity, conductivity, density and refractive index all change approximately regularly with the increase of temperature, while pH value remains almost constant when the temperature exceeds 325 K. The catalytic ability of the three DESs in the esterification reaction of palmitic acid and ethanol was investigated, and DES2 was selected as the catalyst for subsequent experiments. The effects of temperature, acid-ethanol molar ratio, catalyst dosage and reaction time on esterification reaction were further studied, and DES’ recyclability was also tested. The results obtained showed the great potential of DES in catalytic applications.

Polyvinyl Butyral Synthesis Process Based on Deep Eutectic Solvent as a Catalyst

Polyvinyl butyral (PVB) was prepared by the condensation reaction of polyvinyl alcohol (PVA) with n-butyraldehyde using a catalyst which is a kind of deep eutectic solvent (DES) made of dodecyltrimethylammonium chloride and p-toluenesulfonic acid. The raw materials and products were characterized by Fourier transform infrared spectroscopy (FT-IR). The effects of the following reaction conditions on the degree of PVB acetal, yield and agglomeration of the products were investigated: the mass ratio of n-butyraldehyde to PVA (mBA/mPVA) of 0.48-0.96, the mass ratio of catalyst to PVA (mcat/mPVA) of 0.16-0.64, the low temperature reaction temperature (5-20℃), and the low temperature reaction time (1-3h). The results showed that at mBA/mPVA =0.8, mcat/mPVA =0.32, low temperature reaction temperature of 15°C and low temperature reaction time of 2 hours, the obtained PVB was a homogeneous powder with the highest acetal degree of 73.85%.

Flow performance of a self-assembly biopolymer/β-cyclodextrin/surfactant CO2 foam system in pollutant-free porous media as a flushing agent for in-situ soil remediation applications

The remediation of hydrocarbon contaminated soils is an active research field, in which different remediation technological approaches are currently under evaluation. In this research, a new technology based on a self-assembly biopolymer/β-Cyclodextrin/surfactant (bP/βCD/S) CO2 foam system was evaluated for in-situ soil remediation applications. The biopolymer and surfactant used in this study were xanthan gum and dodecyl trimethylammonium chloride (DTAC), respectively. The stability of the bP/βCD/S and the baseline biopolymer/surfactant, bP/S, CO2 foam systems at different brine salinity and hardness concentrations was evaluated in bulk. Subsequently, the flow behavior and the stability of both foam systems were evaluated through displacement experiments employing unconsolidated sand at different brine concentrations (2.1 and 8.4 wt%) at ambient temperature. The mobility control performance and the stability of both foam systems in contaminant-free sand were evaluated during the displacing experiments using the resistance and the residual resistance factors as performance indicators. The bulk stability tests demonstrate that the bP/βCD/S CO2 foam system displays higher stability relative to the bP/S foam system in both 2.1 wt% (e.g., salinity = 1.73 wt% and hardness = 0.37 wt%) and 8.4 wt% (e.g., salinity = 6.92 wt% and hardness = 1.48 wt%) brine systems. Likewise, the displacement experiments show that the bP/βCD/S CO2 system offers superior mobility control functionality and stability during flow in porous media relative to the baseline polymer/surfactant foam regardless of the brine ionic strength. Consequently, the bP/βCD/S CO2 foam system shows great potential as an effective integrated technology for in-situ soil remediation applications.

Mixed micellization of cationic/anionic amino acid surfactants: Synergistic effect of sodium lauroyl glutamate and alkyl tri-methyl ammonium chloride

In the cleaning field of the cosmetics industry, amino acid surfactants with low irritation and degradability have attracted more and more attention. However, in the actual application system, the amino acid type surfactant has the application difficulty that is not easy to thicken. In this study, the surface activities and application of the surfactant mixtures containing the cationic surfactant dodecyl tri-methyl ammonium chloride (DTAC) and anionic amino acid surfactant sodium lauroyl glutamate (SLG) (cationic/anionic amino acid surfactant system) were systematically studied, which will provide theoretical guidance for practical applications. First, the surface tension of the cationic/anionic amino acid surfactant system was measured, and the CMC value, interaction parameters, Gibbs free energy and other data were obtained. From this, the behavior characteristics of the adsorption and aggregation of SLG and DTAC in the solution can be judged. Then through dynamic light scattering instrument, rheometer, polarizing microscope, etc., we analyze the phase behavior of the cationic/anionic amino acid surfactant system under different compound ratios and different concentrations, and draw a pseudo-ternary phase diagram. Finally, the influence of the length of the hydrophobic chain of cationic surfactants on the phase behavior of amino acid surfactants was investigated. Experiments have found that the addition of cationic surfactant DTAC can significantly reduce the CMC value of the SLG system, and the CMC changes with the increase of the SLG ratio as follows: first decrease and then increase. The interaction parameters show that DTAC and SLG have a strong interaction. Contrary to the phenomenon of precipitation after the compounding of conventional cationic/anionic surfactants, the compounding of DTAC and SLG increases the solubility, reduces the Krafft point of SLG, and increases the application performance. At the same time, the problem of difficult control of the viscosity of the amino acid surfactant system has also been better solved. DTAC and SLG form a worm-like mixed micelle, which has a higher and controllable viscosity. Finally, it was found that changing the hydrophobic chain length of cationic surfactants has a direct effect on the viscosity of the system.

Organophilic clays and their application in atrazine adsorption

Atrazine’s adsorptive capabilities make the use of clays practical and effective. Three types of organophilic clays modified by cationic surfactants with the ability of one of these clays to adsorb atrazine in an aqueous medium are discussed in this work. The modification in clays was done with the surfactants cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, and dodecyltrimethylammonium chloride. The X-ray diffraction data indicated different lamellar expansions for the three organophilic clays obtained when compared to in natura clay, proving the presence of quaternary ammonium salts in the interlamellar space. There was also a decrease in the specific surface area showing less accessibility to the lamellar spaces due to the presence of surfactants. The thermogravimetric analysis showed a negative variation profile in all the clays. The adsorption test showed a better capacity for atrazine adsorption in the organophilic clay of 64% when compared with 36% of in natura clay, and it followed the Freundlich isotherm model.

Biodegradability and toxicity of dodecyl trimethyl ammonium chloride in sea water.

Studies were conducted to assess the biodegradability and toxicity of the cationic surfactant dodecyl trimethyl ammonium chloride (DTMAC) in sea water samples collected from the Gulf of Cadiz (Spain). Ultimate biodegradation was studied following the guideline proposed by the United States Environmental Protection Agency (USEPA). Growth inhibition tests on five marine microalgae species and mortality tests on a marine crustacean (Artemia franciscana) were carried out. Biodegradation process was modelled according to a logistic kinetic model. Lag time and half-life were 15.17 and 26.95 days, respectively. Depending on the microalgae, 96-h EC50 values ranged from 0.69 to 6.34 mg L-1 DTMAC, respectively. 48-h and 72-h LC50 to A. franciscana were 46.74 and 34.19 mg L-1 DTMAC, respectively. The results indicate that DTMAC can be mineralised in sea water. Marine crustacean was more resistant than the microalgae. Surfactant tolerance on microalgae followed this order: T. chuii > N. gaditana > C. gracilis ≈ I. galbana ≈ D. salina, being the Green microalgae T. chuii the most tolerant.

Single-Crystalline Mesoporous Palladium and Palladium-Copper Nanocubes for Highly Efficient Electrochemical CO 2 Reduction

Single-Crystalline Mesoporous Palladium and Palladium-Copper Nanocubes for Highly Efficient Electrochemical CO ₂ Reduction

Light‐Emitting Metal–Organic Halide 1D and 2D Structures: Near‐Unity Quantum Efficiency, Low‐Loss Optical Waveguide and Highly Polarized Emission

AbstractOrganic–inorganic metal‐halide materials (OIMMs) with zero‐dimensional (0D) structures offer useful optical properties with a wide range of applications. However, successful examples of 0D structural OIMMs with well‐defined optical performance at the micro‐/nanometer scale are limited. We prepared one‐dimensional (1D) (DTA)2SbCl5⋅DTAC (DTAC=dodecyl trimethyl ammonium chloride) single‐crystal microrods and 2D microplates with a 0D structure in which individual (SbCl5)2− quadrangular units are completely isolated and surrounded by the organic cation DTA+. The organic molecular unit with a long alkyl chain (C12) and three methyl groups enables microrod and ‐plate formation. The single‐crystal microrods/‐plates exhibit a broadband orange emission peak at 610 nm with a photoluminescence quantum yield (PLQY) of ca. 90 % and a large Stokes shift of 260 nm under photoexcitation. The broad emission originates from self‐trapping excitons. Spatially resolved PL spectra confirm that these microrods exhibit an optical waveguide effect with a low loss coefficient (0.0019 dB μm−1) during propagation, and linear polarized photoemission with a polarization contrast (0.57).

Light-Emitting Metal-Organic Halide 1D and 2D Structures: Near-Unity Quantum Efficiency, Low-Loss Optical Waveguide and Highly Polarized Emission.

Organic-inorganic metal-halide materials (OIMMs) with zero-dimensional (0D) structures offer useful optical properties with a wide range of applications. However, successful examples of 0D structural OIMMs with well-defined optical performance at the micro-/nanometer scale are limited. We prepared one-dimensional (1D) (DTA)2 SbCl5 ⋅DTAC (DTAC=dodecyl trimethyl ammonium chloride) single-crystal microrods and 2D microplates with a 0D structure in which individual (SbCl5 )2- quadrangular units are completely isolated and surrounded by the organic cation DTA+ . The organic molecular unit with a long alkyl chain (C12 ) and three methyl groups enables microrod and -plate formation. The single-crystal microrods/-plates exhibit a broadband orange emission peak at 610 nm with a photoluminescence quantum yield (PLQY) of ca. 90 % and a large Stokes shift of 260 nm under photoexcitation. The broad emission originates from self-trapping excitons. Spatially resolved PL spectra confirm that these microrods exhibit an optical waveguide effect with a low loss coefficient (0.0019 dB μm-1 ) during propagation, and linear polarized photoemission with a polarization contrast (0.57).

Improved methane storage capacity of methane hydrate promoted by vesicles from carboxylate surfactants and quaternary ammonium

The maximum methane storage capacity (MSC) is of critical importance of methane hydrate to store methane. This paper reports the effects of vesicle solutions, formed through combination of carboxylate surfactants with cationic quaternary ammonium salt including hydroxypropyl trimethyl ammonium chloride chitosan (HACC) or dodecyl trimethyl ammonium chloride (DTAC), on the formation of methane hydrate. It was found that vesicles could raise the maximum MSC of hydrate by about 10 (V/V, the volume of methane stored by one volume of hydrate) at appropriate anion and cation concentrations. For example, at 800 ppm (parts per million) of sodium laurate (SL) and 600 ppm of HACC concentrations, the formed vesicles could elevate the maximum capacity to 151 V/V, 5.3% higher than that of sodium laurate alone. The vesicles formed could increase the maximum MSC, from 136 V/V to 147 V/V by sodium oleate (SO) and HACC, 145 V/V to 153 V/V by sodium decanoate (SD) and HACC and 137 V/V to 149 V/V by SO and DTAC. The reason for the enhancement is that the large hydrophobic space of the vesicles could solubilize methane molecules and facilitate them to contact with water molecules.

Inhibitory effects of developed composite anti-aging agent on microbial degradation of asphalt

The shady, humid, or polluted asphalt pavement is often subjected to microorganism degradation, leading to microbial aging. To reduce the microbial aging of asphalt pavement, a composite anti-microbial aging agent was developed, and its effects on physicochemical properties of asphalt after degraded by microbial consortia for different aging periods were discussed. Test results indicate that the content of macromolecules in asphalt decreases, while the content of small molecules increases as the aging time is prolonged. The composite anti-microbial aging agent inhibits the reproduction of microbial consortia on asphalt. Further, carbon (C) element mainly presents as C–H and C–C bonds in asphalt. After aged by microbial consortia, C element content in hydrocarbons decreases, but in alcohols or hydroxyl group increases, and in carbonyl group almost unchanges. The dodecyl trimethyl ammonium chloride (DTAC) and hexadecyl trimethyl ammonium bromide (CTAB) in composite anti-microbial aging agent damage the protein structures of microorganisms to become inactive. Then microorganisms are decomposed into alcohols, phenols, carboxylic acids, etc. The zinc oxide nanoparticles (nano-ZnO) retain original crystal structures in asphalt and achieve the bacteriostatic effect through penetrating into microbial cells. The compounding scheme with DTAC: CTAB: nano-ZnO = 1:1:1 by weight shows a higher anti-microbial aging effect on the reproduction of microbial consortia on asphalt. This proportion is proposed to prepare a new composite ant-microbial aging agent for shady, humid, or polluted asphalt pavement asphalt pavement at scenicarea countryside and forest region.

Cellulose nanofiber-reinforced rubber composites prepared by TEMPO-functionalization and elastic kneading

Aqueous dispersion consisting of 2,2,6,6-tegramethylpyperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TEMPO-CNFs), dodecyltrimethylammonium chloride (DTMACl), and diethylene glycol (DEG) was oven-dried at 40 °C for 1 d to prepare a dried product. The soft and bulky TEMPO-CNF/DTMACl/DEG material was added to a carboxy group-containing nitrile-butadiene rubber (XNBR) followed by removal of all the DEG molecules by vacuum drying at 80 °C for 8 h. The mixture was then subjected to kneading with high shear forces using a two-roll mill at 20–30 °C (i.e., elastic kneading), followed by pressing at 170 °C for 20 min to prepare cross-linked XNBR composite sheets consisting of TEMPO-CNF and DTMACl. The XNBR composite sheet containing 9.9 vol% TEMPO-CNF had an average tensile strength, storage modulus at 23 °C, work of fracture, and elongation at break of 19 MPa, 47 MPa, 2.7 MJ/m3, and 230%, respectively, whereas those of the reference cross-linked XNBR sheet were 11 MPa, 11 MPa, 0.9 MJ/m3, and 220%, respectively. Scanning transmission electron microscopy observation revealed unique fibrillated and cluster-like structures of the TEMPO-CNF were likely responsible for the excellent mechanical and thermal properties. The proposed process is industrially viable for conventional kneading processes to prepare composite rubber sheets with good mechanical and thermal properties.

High-strength porous alumina ceramics prepared from stable wet foams

Porous ceramics have been widely used in heat insulation, filtration, and as a catalyst carrier. Ceramics with high porosity and high strength are desired; however, this high porosity commonly results in low strength materials. In this study, porous alumina with high porosity and high strength was prepared by a popular direct foaming method based on particle-stabilized wet foam that used ammonium polyacrylate (PAA) and dodecyl trimethyl ammonium chloride (DTAC) as the dispersant and hydrophobic modifier, respectively. The effects of the dispersant and surfactant contents on the rheological properties of alumina slurries, stability of wet foams, and microstructure and mechanical properties of sintered ceramics were investigated. The microstructure of porous ceramics was regulated using wet foams to achieve high strength. For a given PAA content, the wet foams exhibited increasing stability with increasing DTAC content. The most stable wet foam was successfully obtained with 0.40 wt% PAA and 0.02 wt% DTAC. The corresponding porous alumina ceramics had a porosity of 82%, an average grain size of 0.7 µm, and a compressive strength of 39 MPa. However, for a given DTAC content, the wet foams had decreasing stability with increasing PAA content. A possible mechanism to explain these results is analyzed.

Reduced Biofilm Formation at the Air-Liquid-Solid Interface via Introduction of Surfactants.

Reduced biofilm formation is highly desirable in applications ranging from transportation to separations and healthcare. Biofilms often form at the three-phase interface where air, liquid, and solid coexist due to the close proximity to nutrients and oxygen. Reducing biofilm formation at the triple interface presents challenges because of the conflicting requirements for hydrophobicity at the air-solid interface (for self-cleaning properties) and for hydrophilicity at the liquid-solid interface (for reduced foulant adhesion). Meeting those needs simultaneously likely entails a dynamic surface, capable of shifting the surface energy landscape in response to wetting conditions and thus enabling hydrophobicity in air and hydrophilicity in water. Here, we designed a facile approach to render existing surfaces resistant to biofilm formation at the triple interface. By adding trace amounts (∼0.1 mM) of surfactants, biofilm formation of Pseudomonas aeruginosa (known to form biofilm at the triple interface) was reduced on all surfaces tested, ranging from hydrophilic to hydrophobic, polar to nonpolar. That reduced fouling was not a result of the known antimicrobial effects. Instead, it was attributed to the surface-adsorbed surfactants that dynamically control surface energy at the triple interface. To further understand the effect of surfactant-surface interactions on biofilm reduction, we systematically varied the surfactant charge type and surface properties (surface energy and charge). Electrostatic interactions between surfactants and surfaces were identified as an influential factor when predicting the relative fouling reduction upon introduction of surfactants. Nevertheless, biofilm formation was reduced even on the charge-neutral, fluorinated surface made of poly(1H, 1H, 2H, 2H-perfluorodecyl acrylate) by more than 2-fold simply via adding 0.2 mM dodecyl trimethylammonium chloride or 0.3 mM sodium dodecyl sulfate. Given its robustness, this strategy is broadly applicable for reducing fouling on existing surfaces, which in turn improves the cost-effectiveness of membrane separations and mitigates contaminations and nosocomial infections in healthcare.

The effect of sodium dodecyl sulfate and dodecyltrimethylammonium chloride on the kinetics of CO2 hydrate formation in the presence of tetra-n-butyl ammonium bromide for carbon capture applications

Tetra-n-butyl ammonium bromide (TBAB) is a commonly used promoter to moderate CO2 hydrate phase equilibrium. However, it decreases CO2 gas uptake. In this work, the effects of anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant dodecyltrimethylammonium chloride (DTAC) on the kinetics of CO2–TBAB hydrate formation are investigated. Experiments in a batch reactor at the same initial pressure of CO2/N2 gas mixtures are conducted in systems of 10-wt% TBAB and varied SDS concentrations of 0–1500 ppm and DTAC concentrations of 0–0.6 wt%. Induction time, normalized gas uptake, split fraction and separation factor are the metrics to study in this paper. The results show that the hydrate formation is most accelerated with the addition of SDS, and the best CO2 separation performance is achieved in the presence of DTAC. 10-wt%TBAB with 0.1-wt% DTAC is found to be the optimum recipe, and it leads to the same amount of CO2 uptake at 283.15 K as that in a pure water system at 276.45 K under the same initial pressure. CO2 uptake is also found to increase with a higher subcooling. Furthermore, the intensive uptake period of different systems is determined for practical applications of hydrate-based carbon capture.

The role of phase transfer catalysts on properties of polyamide thin-film composite forward osmosis membranes

In this article, 1,3,5-benzenetricarbonyl trichloride (TMC), m-phenylenediamine (MPD) and phase transfer catalysts (PTCs) were used to produce polyamide thin-film composite (TFC) forward osmosis (FO) membranes through interfacial polymerization (IP) reaction. The effects of dodecyl trimethyl ammonium chloride (DTAC), sodium dodecyl sulphate (SDS) and dodecyl dimethyl betaine (BS12) on the polyamide molecular aggregation structures, surface morphology and FO separation performance of the membranes were systematically investigated. In the FO process, concentrated 1.0 M NaCl aqueous solution was chosen as the draw solution and 0.1 M NaCl aqueous solution was used as the feed solution (at room temperature). Separation performance included the water flux (Jw) and reverse salt rejection (reverse solute flux, RS). The experiment proved that PTCs can regulate the molecular chain aggregation state and surface morphology of polyamide, which can lead to a relatively definite improvement in water flux (11.5 L m−2 h−1) (DTAC-polyamide). Simultaneously, the polyamide surface morphology was found to play a major role in the water permeability of the FO membrane rather than the density of the skin layer (i.e., degree of cross-linking), and we found that a relatively smooth surface is more conducive to weakening the external concentration polarization (ECP) phenomenon that occurs in the FO process. We attribute this mechanism on polyamide to the size effect and charge interaction of PTCs. In the current study, the balanced effect of the synergistic interaction of the molecular structure and rough surface of polyamide on FO separation performance should be comprehensively considered.

Study on Binary Mixture System of Lauroyl Sodium Glutamate Surfactant

Abstract In the present study, binary mixtures of sodium N-lauroylglutamate (SLG) and dodecyltrimethylammonium chloride (DTAC) or dodecylbetaine (BS-12) were examined for their synergistic effect. The surface chemical properties of the compound systems with different molar ratios were determined by the regular solution theory. Results indicated that both compound systems show synergistic effects of overall synergy, in which the SLG/DTAC system exhibited a better activity than the SLG/BS-12 system. The aggregation number of SLG compound systems was smaller than that of single surfactants, and the difference of the proportion of the two surfactants had little effect on the aggregation number of compound systems.

Anti-biofilm activity of dodecyltrimethylammonium chloride microcapsules against Salmonella enterica serovar Enteritidis and Staphylococcus aureus

Dodecyltrimethylammonium chloride (DTAC) was trapped into maltodextrins/pectin spray dried microcapsules to improve its activity against Salmonella enteritidis and Staphylococcus aureus biofilms. Two different microcapsules were prepared: uncomplexed DTAC-microcapsules (UDM), containing DTAC and maltodextrins; and complexed DTAC-microcapsules (CDM) containing DTAC complexed with pectin and maltodextrins. The minimum inhibitory concentrations (MIC) of both free and microencapsulated DTAC were investigated against S. Enteritidis and S. aureus. The MICs of DTAC were significantly lower when encapsulated. CDM treatment resulted in a 2 and 3.2 log reduction in S. aureus and S. Enteritidis biofilm culturable biomass, respectively. Microencapsulation reduced the cytotoxicity of DTAC by up to 32-fold. Free DTAC and CDM targeted the cell membrane resulting in the leakage of the intracellular molecules and subsequent cell death. The development of DTAC microcapsules reduced the amount of DTAC required to maintain the high standards of cleanliness and hygiene required in the food processing industries.