Myristyltrimethylammonium Bromide Research Articles

Sulfur quantum dots stabilized by myristyl trimethylammonium bromide

For the first time, sulfur quantum dots (SQDs) were obtained in the presence of the cationic surfactant myristyl trimethylammonium bromide (MTAB) using two approaches: “bottom-up” and “top-down”. The synthesis of SQDs from sodium thiosulfate in presence of MTAB required 2 h heating at 70 °C resulting in a solution with stable photoluminescence (quantum yield 18 %). SQDs from sulfur were fabricated during 12 h heating only after etching by hydrogen peroxide. It has been established that the hydrogen peroxide is ineffective agent for SQDs syntheses from sodium thiosulfate (“bottom-up” technique).

Tailoring poly(2-ethyl-2-oxazoline) towards effective mitigation of chloride-induced dissolution of S235JR steel: The synergistic contributions of potassium iodide and myristyl trimethylammonium bromide

Organic compounds that exhibit little or no toxicity, have high solubility properties, and are affordable are highly sought after as metal corrosion inhibitors. The key to formulating an effective and economically viable corrosion inhibitor is the identification of compounds with strong synergistic effects. The synergistic inhibition of S235JR carbon steel in 1 M HCl by poly(2-ethyl-2-oxazoline) (PO), KI, and myristyl trimethylammonium bromide (MTAB) is studied. The durability of the PO + KI + MTAB blend is examined for up to 72 h. Results reveal an average inhibition efficiency (η) of 80 % for PO at 1000 mg/L. Adding 5 mg/L KI or MTAB to 1000 mg/L PO raised η to 97 % or 94 % from EIS measurements. PO(1000 mg/L) + KI(5 mg/L) + MTAB(5 mg/L) produced ∼ 99 % inhibition and kept the corrosion rate at 0.09 mm/y for up to 72 h. Spectroscopic and computational studies reveal PO interacted with the steel surface making use of the carbonyl functional group. The DFT calculations and MD simulations confirm the favorable tendency of the PO molecule to adsorb on the metal surface and the synergistic adsorption with KI and MTAB. Furthermore, SEM and AFM results confirm the high inhibitive performance of the blend. PO + KI + MTAB blend is highly recommended for long-term acid pickling of a metal surface and acid cleaning of plants.

Spectroscopic and Microestructural Evidence for T-2 Toxin Adsorption Mechanism by Natural Bentonite Modified with Organic Cations

Aluminosilicates are adsorbents able to bind mycotoxins, and their chemical modification increases their affinity to adsorb low-polarity mycotoxins. To further investigate if the inclusion of salts in bentonite modifies its adsorptive capacity, we studied T-2 toxin adsorption in natural bentonite (NB) and when modified with quaternary ammonium salts differing in polarity and chain length: myristyl trimethyl ammonium bromide (B14), cetyl trimethyl ammonium bromide (B16) and benzyl dimethyl stearyl ammonium chloride (B18). The results showed that quaternary salts made bentonite: displace monovalent (Na+1, K+1) and divalent (Mg+2, Ca+2) ions; reduce its porosity; change its compaction and structure, becoming more crystalline and ordered; and modify the charge balance of sheets. T-2 adsorption was higher in all modified materials compared to NB (p ≤ 0.0001), and B16 (42.96%) better adsorbed T-2 compared to B18 (35.80%; p = 0.0066). B14 (38.40%) showed no differences compared to B16 and B18 (p > 0.05). We described the T-2 adsorption mechanism in B16, in which hydrogen bond interactions, Van der Waals forces and the replacement of the salt by T-2 were found. Our results showed that interaction types due to the inclusion in B16 might be more important than the hydrocarbon chain length to improve the adsorptive capacity of bentonite.

Experimental Composite Resin with Myristyltrimethylammonium Bromide (MYTAB) and Alpha-Tricalcium Phosphate (α-TCP): Antibacterial and Remineralizing Effect.

The aim of this study was to develop an experimental composite resin with the addition of myristyltrimethylammonium bromide (MYTAB) and α -tricalcium phosphate (α-TCP) as an antibacterial and remineralizing material. Experimental composite resins composed of 75 wt% Bisphenol A-Glycidyl Methacrylate (BisGMA) and 25 wt% Triethylene Glycol Dimethacrylate (TEGDMA) were produced. Some 1 mol% Trimethyl benzoyl-diphenylphosphine oxide (TPO) was used as a photoinitiator, and butylated hydroxytoluene (BTH) was added as a polymerization inhibitor. Silica (1.5 wt%) and barium glass (65 wt%) particles were added as inorganic fillers. For remineralizing and antibacterial effect, α-TCP (10 wt%) and MYTAB (5 wt%) were incorporated into the resin matrix (α-TCP/MYTAB group). A group without the addition of α-TCP/MYTAB was used as a control. Resins were evaluated for their degree of conversion (n = 3) by Fourier Transform Infrared Spectroscopy (FTIR). The flexural strength (n = 5) was assessed based on ISO 4049:2019 requirements. Microhardness was assessed to calculate softening in solvent (n = 3) after ethanol immersion. The mineral deposition (n = 3) was evaluated after immersion in SBF, while cytotoxicity was tested with HaCaT cells (n = 5). Antimicrobial activity (n = 3) was analyzed against S. mutans. The degree of conversion was not influenced by the antibacterial and remineralizing compounds, and all groups reached values > 60%. The α-TCP/MYTAB addition promoted increased softening of polymers after immersion in ethanol and reduced their flexural strength and the viability of cells in vitro. A reduction in S. mutans viability was observed for the α-TCP/MYTAB group in biofilm formation and planktonic bacteria, with an antibacterial effect > 3log10 for the developed materials. Higher intensity of phosphate compounds on the sample's surface was detected in the α-TCP/MYTAB group. The addition of α-TCP and MYTAB promoted remineralizing and antibacterial effects on the developed resins and may be a strategy for bioactive composites.

Characteristics of MSNs synthesized by structure directing method

The high specific surface area (SSA) mesoporous silica nanoparticles (MSNs) are synthesized and characterized in this work. The structure directing method combined with the co-condensation and bi-phasic processes are employed to fabricate the porous particles. Myristyltrimethylammonium bromide (MTAB) is utilized as the major structure directing agent. Triton X-100 and triethanolamine (TEA) are employed as the co-structure directing agents. In order to generate a bi-phasic environment and increase the reaction rate, cyclohexane (CHX) and L-Arginine (LAG) are used, respectively. To swelling of the structure directing agents, the solution of structure directing agents, solvent and catalyst is subjected to sonicate by ultrasonic wave with the frequency of 40 kHz. In the research, as synthesized sample of particles are characterized by different scientific techniques. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are utilized to analyze the morphology and pore formed on the obtained particles. The N2 adsorption-desorption isotherm testing integrated with the BET and BJH calculation techniques are employed to determine the SSA, mean pore diameter and total pore volume of the resultant particles at relative pressure of 0.99. Results from the tests as mentioned revealed that SSA of particles synthesized by using only MTAB as a structure directing agent, is about 672.30 m2/g while SSA of particles fabricated by using MTAB+TEA and MTAB+triton X-100 is 691.45 and 651.93 m2/g, respectively. A mean pore diameter and total pore volume of the obtained particles are 4.9, 7.5, 3.9 nm and 0.83, 1.30, 0.63 cm3/g when MTAB, MTAB+TEA and MTAB+X-100 are used as structure directing agents, respectively. Porous particles with uniform size distribution are successfully synthesized and confirmed by SEM and TEM micrographs, respectively. Finally, TEM-EDX confirmed that the synthesized particles are silica (SiO2) nanoparticles.

Amino-Functionalized Pore-Expanded MCM-41 for CO2 Adsorption: Effect of Alkyl Chain Length of the Template

Solid adsorbents modified with N-containing functional groups have been extensively studied due to their excellent CO2 adsorption performance. In this work, an adsorbent was obtained to capture CO2 by impregnating polyethylenimine (PEI) into MCM-41 with a reserved template that had different alkyl chain lengths [myristyltrimethylammonium bromide (C14), cetyltrimethylammonium bromide (C16), and stearyltrimethylammonium bromide (C18)]. The thermogravimetric analysis, small-angle X-ray diffraction, N2 adsorption–desorption, Fourier transform infrared (FTIR) spectroscopy analysis, and in situ FTIR spectra were employed to study the properties of adsorbents. The results showed that the template had been successfully introduced into the supports in the synthetic process, and the CO2 adsorption performance was quite sensitive to the alkyl chain length of the template. Besides, the adsorbent with the template (C16) exhibited the highest CO2 adsorption capacity (2.49 mmol/g) and amine utilization rate (0.28 mmol CO2/mmol N) under 25 °C and pure CO2. It is believed that the appropriate alkyl chain length of the template could act as an important role in the enhancement of PEI distribution and decrease the CO2 transfer resistance, thereby improving the CO2 adsorption capacity.

Stability of Two-Dimensional Liquid Foams under Externally Applied Electric Fields.

Liquid foams are highly complex systems consisting of gas bubbles trapped within a solution of surfactant. Electroosmotic effects may be employed to induce fluid flows within the foam structure and impact its stability. The impact of external electric fields on the stability of a horizontally oriented monolayer of foam (2D foam) composed of anionic, cationic, non-ionic, and zwitterionic surfactants was investigated, probing the effects of changing the gas–liquid and solid–liquid interfaces. Time-lapse recordings were analyzed to investigate the evolution of foam over time subject to varying electric field strengths. Numerical simulations of electroosmotic flow of the same system were performed using the finite element method. Foam stability was affected by the presence of an external electric field in all cases and depended on the surfactant type, strength of the electric field, and the solid material used to construct the foam cell. For the myristyltrimethylammonium bromide (MTAB) foam in a glass cell, the time to collapse 50% of the foam was increased from ∼25 min under no electric field to ∼85 min under an electric field strength of 2000 V/m. In comparison, all other surfactants trialed exhibited faster foam collapse under external electric fields. Numerical simulations provided insight as to how different zeta potentials at the gas–liquid and solid–liquid interfaces affect fluid flow in different elements of the foam structure under external electric fields, leading to a more stable or unstable foam.

In Situ Growth Synthesis of the CNTs@AC Hybrid Material for Efficient Nitrate-Nitrogen Adsorption.

Nitrate-nitrogen (NO3–N) is a common pollutant in aquatic environments and causes many environmental issues and health problems. This study successfully applied the activated AC@CNT composite synthesized by CNTs in-situ growth and post-treated by myristyltrimethylammonium bromide (MTAB) for NO3–N adsorption from wastewater. The results show that the highest NO3–N adsorption capacity of AC@CNTs-M was 14.59 mg·g–1. The in-situ growth of CNTs gave a higher specific surface area and more mesoporous volume, while MTAB uniformly occupied part of the pore structure after the modification process. The AC@CNTs-M had more surface functional groups of hydroxyl and carboxyl, which are favorable for the adsorption of NO3–N. The NO3–N adsorption on AC@CNTs-M was best defined by the pseudo-second-order model, and the isothermal analysis shows that NO3–N adsorption is a multiple process with a maximum adsorption capacity of 27.07 mg·g–1. All the results demonstrate the great potential of AC@CNTs-M for NO3–N adsorption from water, especially in acidic wastewater.

Interaction of hairy carboxyalkyl cellulose nanocrystals with cationic surfactant: Effect of carbon spacer

Tuning the surface chemistry of nanocellulose is essential for developing its end-use applications. Herein, different carboxyalkylated cellulose nanocrystals (CNC) with similar charge densities but with tunable hairy structures were produced. The effect of carbon spacer of the grafted groups on the interaction of the CNC and a cationic surfactant, myristyl trimethyl ammonium bromide (MTAB), at different pH and salinity was explored. The CNC with longer grafted chain length was more hydrophobic, adsorbed more MTAB, and formed a more compact MTAB adlayer than did CNC with the shorter chain length. Also, the adsorption was higher at neutral pH, implying a high electrostatic attraction and hydrophobic interaction between substrates. The hydrophobic interaction of MTAB and hairy CNC in saline systems improved its adsorption. Although MTAB adsorbed more when its concentration was higher than its critical micelle concentration (CMC), the adsorbed adlayer had a less compact structure on the CNC surfaces.

The “molecule diode” effect caused by adsorbed surfactant layers improves evaporation efficiency in the bubble column evaporator (BCE) for seawater desalination

The bubble column evaporator (BCE) can be used as an improved thermal desalination technology simply based on pumping a heated gas, such as helium, through a porous sinter to produce hot gas bubbles to transfer heat and mass across the water-gas interface. In this paper, a “molecule diode” effect caused by surfactant monolayers has been proposed, because adding surfactants into the column solution produced an improved evaporation efficiency. The mechanism involved appears to be based on enhancing water molecule transport across the bubble surfaces from the column solution via the hydrophilic headgroups, whilst restricting water vapour molecules returning to the solution because of the layer of hydrophobic tails coating the inside bubble surface. In this paper, the enthalpy of vaporization (△Hv) was estimated, and the bubble saturation period and the bubbling and foaming behaviour was observed, to study the performance of surfactants on improving the evaporation efficiency achieved by the BCE process. Myristyltrimethylammonium bromide (MAB), a typical cationic surfactant, combined with the moderately heated helium bubbles generated in the BCE column, performed best by reducing the apparent △Hv value for water by 15 % and increasing the evaporation efficiency by 2.3 times, compared with the value for non-surfactant column solutions pumped with air, which demonstrates the potential for a low cost thermal desalination technology based on this sub-boiling process.

Abnormal behaviors in the calibration curves of liquid chromatography-tandem mass spectrometry occurring in the quantitative analysis of surfactants near critical micelle concentrations.

Surfactants, including quaternary ammonium compounds, are widely used in daily life as part of consumer chemical products and, more recently, in the shale oil industry. Because of their unique amphiphilic properties, surfactants form micelles at concentrations above a certain threshold known as the critical micelle concentration (CMC). A previous electrospray ionization mass spectrometry studies conducted by Siuzdak et al. and others presented indirect evidence regarding micelle formation. Herein, we have used liquid chromatography-tandem mass spectrometry to explore how such micelle formations affect the quantitative analysis of surfactants. Results reveal abnormal behaviors in the calibration plots of a few selected anionic and cationic surfactants, such as sodium decyl sulfate (SDeS), sodium dodecyl sulfate (SDS), myristyltrimethylammonium bromide (MTAB), and benzyldimethyloctadecylammonium chloride (BAC-18). At concentrations close to the respective CMCs of these surfactants, the calibration plot for MTAB flattened, whereas the slopes of the calibration plots for SDeS, SDS, and BAC-18 suddenly changed. These abnormal behaviors can be related to micelle formation. From a practical perspective, the above observations suggest that in the quantitative analysis of surfactants, high micelle concentrations close to the CMC should be avoided to obtain accurate surfactant measurements.

Evaluation of surfactant templates for one-pot hydrothermal synthesis of hierarchical SAPO-5

Abstract Hierarchical SAPO-5 molecular sieves were synthesized with three different mesopore structure-directing agents (meso-SDAs) (cetyltrimethylammonium bromide (CTAB), myristyltrimethylammonium bromide (MTMAB) and [3-(trimethoxysilyl)propyl] dimethyloctadecylammonium chloride (TPOAC)) based on a soft-template hydrothermal synthesis procedure. To investigate the modified porosity of the hierarchical SAPO-5s, they were characterized thoroughly with the results being compared to the conventional microporous SAPO-5. Nitrogen sorption measurements revealed considerable hysteresis loops for the hierarchical SAPO-5s as well as larger mesopore volumes (≥0.15 cm3 g-1) compared to the conventional SAPO-5 (0.05 cm3 g-1). The relative number of acid sites for each sample was calculated from FTIR adsorption data and was in the order of C-SAPO-5>H-CTAB>H-MTMAB>H-TPOAC. The hierarchical SAPO-5s had a significantly increased lifetime (>150 h) in the methanol to hydrocarbons (MTH) model reaction compared to the conventional SAPO-5 (

Hydrophobic ion pair loaded self-emulsifying drug delivery system (SEDDS): A novel oral drug delivery approach of cromolyn sodium for management of bronchial asthma.

The aim of the present study is to develop a self-emulsifying drug delivery system (SEDDS) for the hydrophobic ion pair (HIP) complex of cromolyn sodium (CS), in order to enhance its intestinal absorption and biological activity. Two ion pairing agents (IPAs) were investigated: hexadecyl pyridininum chloride (HPC) and myristyl trimethyl ammonium bromide (MTAB). The optimum binding efficiency for complexation between investigated IPAs and CS was observed at a molar ratio of 1.5:1, where CS binding efficiency was found to be 76.10±2.12 and 91.37±1.73% for MTAB and HPC, respectively. The two prepared complexes exhibited a significant increase in partition coefficient indicating increased lipophilicity. The optimized CS-HIP complex was incorporated into SEDDS formulations. SEDDS formulations F2 (40% oleic acid, 40% BrijTM98, 20% propylene glycol) and F3 (25% oleic acid, 50% BrijTM98, 25% propylene glycol) exhibited nanometric droplet diameters with monodisperse distribution and nearly neutral zeta potential values. Ex vivo intestinal permeation study, using the non-everted gut sac technique, revealed a significantly higher cumulative amount of permeated drug, after 2h, for F2 and F3 (53.836 and 77.617µg/cm2, respectively) compared to 8.649µg/cm2 for plain CS solution. The in vivo evaluation of plain CS solution compared to F2 and F3 was conducted in an ovalbumin sensitization-induced bronchial asthma rat model. Lung function parameters (tidal volume and peak expiratory flow), biochemical parameters (interleukin-5, immunoglobulin-E, myeloperoxidase and airway remodelling parameters) were assessed in addition to histopathological examination. The results indicated the superiority of F3 followed by F2 compared to plain CS solution for prophylaxis of bronchial asthma in rats.

Myristyltrimethylammonium Bromide (MYTAB) as a Cationic Surface Agent to Inhibit Streptococcus mutans Grown over Dental Resins: An In Vitro Study.

This in vitro study evaluated the effect of myristyltrimethylammonium bromide (MYTAB) on the physical, chemical, and biological properties of an experimental dental resin. The resin was formulated with dental dimetacrylate monomers and a photoinitiator/co-initiator system. MYTAB was added at 0.5 (G0.5%), 1 (G1%), and 2 (G2%) wt %, and one group remained without MYTAB and was used as the control (GCtrl). The resins were analyzed for the polymerization kinetics, degree of conversion, ultimate tensile strength (UTS), antibacterial activity against Streptococcus mutans, and cytotoxicity against human keratinocytes. Changes in the polymerization kinetics profiling were observed, and the degree of conversion ranged from 57.36% (±2.50%) for G2% to 61.88% (±1.91%) for G0.5%, without a statistically significant difference among groups (p > 0.05). The UTS values ranged from 32.85 (±6.08) MPa for G0.5% to 35.12 (±5.74) MPa for GCtrl (p > 0.05). MYTAB groups showed antibacterial activity against biofilm formation from 0.5 wt % (p < 0.05) and against planktonic bacteria from 1 wt % (p < 0.05). The higher the MYTAB concentration, the higher the cytotoxic effect, without differences between GCtrl e G0.5% (p > 0.05). In conclusion, the addition of 0.5 wt % of MYTAB did not alter the physical and chemical properties of the dental resin and provided antibacterial activity without cytotoxic effect.

Changes in the CMC/ZrO2 system properties in the presence of hydrocarbon, fluorocarbon and silicone surfactants

The influence of cationic surfactants: hydrocarbon - myristyltrimethylammonium bromide (MTAB), silicone - Silquat J2 (C-Si) and fluorine one (S-106A) on the stabilizing properties of the carboxymethyl cellulose (CMC)/zirconia (ZrO2) system was studied using the spectrophotometric measurements. The obtained results prove that all used polysaccharide/surfactant mixtures can be used as stabilizers of zirconia suspensions, however, the CMC/S-106A mixture is the most effective. The reason for that is formation of the CMC/S-106A complexes with 1:2 stoichiometry and their adsorption on the metal oxide surface. In order to find possible mechanisms of stabilization the CMC adsorption on the ZrO2 was studied. To obtain some information on the structure of the polysaccharide/surfactant/oxide adsorption layer, the surface charge density measurements were conducted. The obtained results can be applied in the fields of ceramics and catalysis.

Chromatographic behavior and characterization of polydisperse surfactants using Ultra-High-Performance Liquid Chromatography hyphenated to High-Resolution Mass Spectrometry

Surfactants are widely used in various petrochemical applications. Thus, it is essential to have highly efficient analytical tools to monitor the different classes of surfactants commonly used. Three among the four known classes of surfactants were studied in the present work: anionic (i.e. alkylbenzene sulfonate, alkyl ether carboxylic acid), nonionic (i.e. alkylcyclohexyl alcohol ethoxylated, alkyl alcohol ethoxylated) and cationic (i.e. alkyl trimethylammonium). Thanks to high-resolution mass spectrometry (HRMS), a useful mass list was created including 119 m/z values (error in mass around 5 ppm). This list was the foundation of a HRMS database, which, for the sake of simplicity, will be further denoted only “database”. To avoid ion competition and streamline attribution of structural formulas for isobar molecules, a suitable chromatographic method was used before MS. The retention behavior of six surfactants (trimethyloctadecylammonium bromide, myristyltrimethylammonium bromide, Brij®C10, Triton X-100 reduced, glycolic acid ethoxylate lauryl ether, 4-dodecylbenzenesulfonic acid) was evaluated under three separation modes: reversed-phase liquid chromatography (RPLC), hydrophilic interaction chromatography (HILIC) and mixed-mode chromatography (combination of anion-exchange and reversed-phase mechanisms). In RPLC mode, six columns were tested including C4, C18, C30, polar-embedded C18, PFP and phenyl chemistries. Two HILIC columns were also tested including bare silica and urea chemistries. An anion-exchange combined with RPLC mechanism was investigated as mixed-mode mechanism. Using ammonium formate at 10 mM as buffer provided the best signal in HRMS. In liquid chromatography, acid conditions (pH 3.5) were preferred, to avoid peak tailing due to residual silanols. The mixed-mode separation mode clearly appears as the best compromise for the characterization of the three surfactants classes. Nevertheless, the orthogonality observed for the separations obtained in HILIC and RPLC modes offers some possibilities for further multidimensional separations.

Synthesis of polymer hybrid latex polystyrene methylmethacrylate-co-butylacrylate with organo-montmorillonite as filler through miniemulsion polymerization for barrier paper application

Nanocomposite have a huge potential in the future technologies and scientific communities. It is possible to design new materials with a simple modification and new materials have different properties and improvement in its mechanical properties and application fields. Hybrid latex based on monomer styrene (St), butyl acrylate (BA) and methylmethacrylate (MMA) have been studied and used for barrier paper applications in food industries in order to replace polypropylene (PP), polyethylene (PE) or polyethylene terephthalate (PET) materials. To achieve better hybrid materials, various techniques and materials have been utilized, montmorillonite (MMT) from smectite family have been selected as filler in order to synthesize polymer clay nanocomposites (PCNs). The selection of MMT as filler due to its high aspect ratio, high modulus and high cation exchange capacity (CEC). MMT was not susceptible to common polymer due to its organophobicity, low basal spacing, and incompatible to common monomers phase. Surface modification of MMT with traditional ion exchange method can be done through ion exchange with quaternary alkyl ammonium surfactants. The objective of surface modification of MMT are to change its nature hydrophilicity to organophilicity, in the same time to increase its basal spacing. Various quaternary alkylammonium cationic surfactants have been used; in this study, three type of alkylammonium were selected to be used due to its different in alkyl carbon chain lengths. Intercalation of surfactants cation in MMT depend on the layer-charge alkyl carbon chains, selection of myristyltrimethylammonium bromide (MTAB) with C17 carbon chains, cetyltrimethylammonium bromide (CTAB) with C19 carbon chains and octadecyltrimethylammonium bromide (OTAB) with C21 carbon chains could give an answer of the selection of organoclay that compatible with St, BA and MMA. This study focuses on the microstructure of organo montmorillonite (OMMT) after surface modification and the potential to be used as filler in synthesis of hybrid latex through miniemulsion polymerization technique. The intercalation or exfoliation of MMT through ion exchange with alkylammonium surfactant were studied, interlayer spacing of OMMT were analysed with X-ray diffraction, small angle X-ray scanning (SAXS) technique, presence of cationic surfactant in the interlayer space and bond character and arrangement of surfactant ions were analysed by Fourier Transform Infrared (FTIR), Thermogravimetric analysis (TGA) and Transmission Electron Microscope (TEM). Synthesis of hybrid latex was done by miniemulsion polymerization technique with selected OMMT filler. Series of experiments were performed to study the polymerization variables such as filler loading, role of surfactant/cosurfactant and filler solubility in monomer emulsions. The results shown that water soluble surfactant SDS in miniemulsion polymerization resulted lower coagulum and smaller particle size compare to non-ionic surfactant (TX405) and cationic surfactant (OTAB). Combination of non-ionic surfactant (TX405) with ionic surfactant (SDS) with ration 1:2 showed the better results than SDS alone, with lowest coagulum, narrow particle size distribution, and lowest Broekfield Viscosity. Scale up loading level of OMMT filler in miniemulsion to 5.0 wt%, resulting instability before and after polymerization with regard to high coagulum content and low monomer conversion rate (<90%). The hybrid latex resulted from miniemulsion polymerization will be applied on paperboard with hand rod coater with coating weight 15-20 gsm. The coated paperboard tested on its water vapour transmission rate (WVTR) together with paperboard coated with PE from melt blending process. Paperboard coated with hybrid latex comparable to paperboard coated with PE, indicated improvement in its WVTR value compare to paperboard coated with latex without filler addition. The main target of this research was to synthesis polymer hybrid latex for super barrier material for food packaging in order to replace unrecyclable PP, PE or PET. The utilization of polymer hybrid latex could benefit paper and paperboard packaging industries.

Self-Retraction of Surfactant Droplets on a Superhydrophilic Surface.

In the present work, an interesting droplet self-retraction phenomenon of myristyltrimethylammonium bromide (C14TAB) solution on the superhydrophilic mica surface was observed. The self-retraction could only occur within a concentration range from 0.01 to 16 cmc. The maximum variation of the contact angle (from 24.99 to 76.85°) was observed in droplets with a concentration of 0.1 cmc. The self-retraction mechanism was studied based on high-speed photography, surface analyses, surface energy calculation, and model fitting. It was proved that there was a monolayer of C14TAB molecules adsorbed on the mica surface, which formed through the electrostatic interaction between the negative mica and the positively charged headgroups. The formation of this monolayer took only a short time of <67 ms since the droplet touched the surface, and the monolayer was well-distributed and hydrophobic with a surface free energy of 76.041 mJ/m2 (20% of mica's surface free energy). The reduction of surface tension led to an imbalance at the borderline of the droplet, causing self-retraction. A model was established to simulate the self-retraction process and it agreed with the experimental data well. This study has significant implication in understanding the surface modification caused by surfactant molecules.

Synthesis of polymer hybrid latex poly(methyl methacrylate-co-butyl acrylate) with organo montmorillonite via miniemulsion polymerization method for barrier paper

Hybrid polymer latex based on combination of organic-inorganic materials, poly(methyl methacrylate-co-butyl acrylate) (PMMBA) and organo-montmorillonite (OMMT) were synthesized via miniemulsion polymerization technique. Modification of montmorillonite (MMT) through the incorporation of myristyltrimethylammonium bromide (MTAB) into the clay’s interlayer spaces were investigated by Small-Angle X-ray Scattering (SAXS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). Barrier property and thermal stability of polymer latex film sample were investigated through its Water Vapor Transmission Rate (WVTR) and Thermogravimetric Analysis (TGA). The results indicated that addition of OMMT as filler in PMMBA increased the barrier property and thermal stability of the latex film. Addition of 8.0% (wt) OMMT increased the barrier property and thermal stability. Miniemusion polymerization process with higher addition (>8.0 wt%) of OMMT resulting in high latex viscosity, particle size, and high amount of coagulum. The utilization of this hybrid polymer could benefits paper and board industries to produce high quality barrier paper for food packaging.

A study of the bubble column evaporator method for improved thermal desalination

A bubble column evaporator (BCE) was used to study the enhanced evaporation of water from 0.5m NaCl solutions, using a range of pre-heated carrier gases (air, CO2, Ar and He), each at an inlet temperature of 150°C. Surprisingly, the use of hot helium as a carrier gas substantially improved water evaporation efficiency, by a factor of about 3 times, compared with, for example, dry air. It is suggested that this higher efficiency could be due to a slightly reduced water hydrogen bonding, and hence enthalpy of vaporisation, due to the continuous sparging of hot He gas atoms into the aqueous solution. These results suggest that this process could form a basis for the development of a more efficient, sub-boiling desalination process. The effect of added cationic and anionic surfactants on BCE water evaporation rate was also studied. The cationic surfactant myristyltrimethylammonium bromide (MAB) and the anionic surfactant Sodium dodecyl sulfate (SDS) each gave a slightly enhanced water evaporation rates, in agreement with previous studies, probably due to enhanced water vapor retention within surfactant coated bubbles.