Trimethoxysilyl Propyldimethyloctadecyl Ammonium Chloride Research Articles

Hybrid Polymer Particles with a Protective Shell: Synthesis, Structure, and Templating

The development of hybrid polymer particles formed by the hydrolytic condensation of octadecyldimethyl(3-trimethoxysilylpropyl)ammonium chloride (ODMACl) and the trisodium salt of the triacetic acid N-(trimethoxysilylpropyl)ethylenediamine (TANED) along with self-assembling with nonionic poly(ethylene glycol) (PEG) based surfactants containing a hydrophobic octadecyl tail (Brij) have been studied using liquid and solid-state NMR, dynamic light scattering (DLS), transmission electron microscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and small-angle X-ray scattering (SAXS). On the basis of DLS and NMR data, the mechanism of interaction of Brij, ODMACl, and TANED molecules in an aqueous solution has been suggested. The influence of the PEG chain length on the ability of surfactants to stabilize polymer particles has been established. The combination of DSC and XRD assessed the crystallinity and thermal properties of self-assembled hybrid materials in the solid state, while SAXS studies revealed that their morphology strikingly depends on the PEG chain length and reaction conditions determining the degree of Brij incorporation and the structure of the Brij−ODMACl complex. Because of the protective PEG shell, the hybrid polymer particles were successfully used as soluble templates for the formation of iron oxide nanoparticles.

Functional Polymer Colloids with Ordered Interior

Polymer colloids with internal ordering were synthesized using hydrolytic condensation of octadecyl-dimethyl(3-trimethoxysilylpropyl)ammonium chloride (ODMACl) and a mixture of ODMACl and the trisodium salt of the triacetic acid N-(trimethoxysilylpropyl)ethylenediamine (TANED). The structure and morphology of these colloids were studied with small-angle X-ray scattering, transmission electron microscopy, nuclear magnetic resonance, sedimentation in ultracentrifuge; and other methods. When polymer colloids are obtained from a single precursor (ODMACl), their local structure, molecular weight characteristics, and morphology strongly depend on the reaction conditions, while lamellar ordering remains nearly unaffected. Use of a mixture of cationic and anionic silanes (ODMACl and TANED) as precursors in hydrolytic condensation results in novel zwitterionic copolymer colloids with two-dimensional hexagonal packing. Interaction of the ODMACl quaternary ammonium groups with the three carboxy groups of TANED leads to replacement of sodium and chloride ions and formation of gegenions, resulting in a molar ratio ODMACl:TANED = 3:1 (each TANED molecule contains three carboxy groups). Due to their ordered interior, polyODMACl (PODMACl) and PODMACl-TANED colloids can be used as templates for controlled positioning of nanoparticles within these colloids. For example, lamellar ordering controls Pt nanoparticle formation within PODMACl colloids providing Pt nanoparticle alignment within the lamellar structure. Loading of PODMACl-TANED colloids with iron salts followed by pH increase results in the formation of iron oxide nanoparticles located within PODMACl-TANED cylinders.

Termite resistance of TMSAC or TMSAH added wood-inorganic composites prepared by the sol-gel process

Antimicrobial SiO2 wood-inorganic composites with 3-(trimethoxysilyl) propyl dimethyl octadecyl ammonium chloride (TMSAC) or 3-(trimethoxysilyl) propyl (carboxymethyl) decylmethyl ammonium hydroxide inner salt (TMSAH) were prepared by the sol-gel process. The obtained TMSAC-Si02 or TMSAH-Si02 composites were studied on their termite resistance to both Reticulitermes speratus (Kolbe) and Coptotermes formosanus Shiraki. Although TMSAC-Si02 composites could not attain the enhanced property in termite resistance, TMSAH-SiO2 only with at most 10% in weight percent gain revealed such a high termite resistance as the treated wood with boric acid which is well-known as a wood preservative against termites.

Survival of Mycobacteria on Hepa Filter Material

Mycobacterium tuberculosis (MTB) is transmitted through the air, and can be captured on ventilation air filters. People handling these filters may be exposed to infectious material. We studied the survival of strains of Mycobacterium on high efficiency particulate air (HEPA) filter material. We used a model ventilation system to evaluate survival over time of Mycobacterium chelonae and H37Ra (an avirulent stain of MTB) aerosolized and then captured on HEPA filter material. Survival curves for M. chelonae incubated at 55% and 75% RH under static conditions were not different with less than 4% survival at 24 hours. H37Ra was subjected to continuous airflow at the design airflow for the filter material following deposition on the HEPA filter material, and less than 0.1% of cells survived to 48 hours (RH not controlled). H37Ra was resistant to immobilized biocide (trimethoxysilylpropyl dimethyloctadecyl ammonium chloride) on HEPA filter material as well as the same biocide in solution. Finally, survival of H37Ra and virulent MTB strain (H37Rv) were not different following deposition onto HEPA filter material from liquid suspension and incubation under static conditions.

ANTIMICROBIAL TMSAC-ADDED WOOD-INORGANIC COMPOSITES PREPARED BY THE SOL-GEL PROCESS

One of the antimicrobial alkoxysilanes, 3-(trimethoxysilyl) propyl dimethyl octadecyl ammonium chloride (TMSAC), was applied to the sol-gel reaction to prepare the antimicrobial wood-inorganic composites from tetraethoxysilane (TEOS). The obtained TMSAC-SiO2 composites revealed some antimicrobial activities, but the use of the property-enhancer, 2-heptadeca-fluorooctylethyltrimethoxysilane (HFOETMOS) in a small quantity could provide water-repellency to the composites which has, further, improved its activities against both white-rot and brown-rot fungi. In addition, after a prolonged soil burial test, TMSAC woods have lost antimicrobial properties, whereas the TMSAC-SiO2, particularly, HFOETMOS-(TMSAC-SiO2) composites could have its high activities maintained. Therefore, it may be concluded that HFOETMOS-(TMSAC-SiO2) and TMSAC-SiO2 composites can provide sustainably high antimicrobial properties in wood.