Development of environmentally friendly,antifouling coatings based on tethered quaternary ammonium salts in a crosslinked polydimethylsiloxane matrix

The concept of tethering quaternary ammonium salts (QASs) to a crosslinked polysiloxane matrix to produce a hybrid antifouling/fouling-release coating was investigated. A statistical experimental design was used to determine the effect of QAS concentration on biocidal activity toward a marine bacterium, Cellulophaga lytica (C. lytica). In addition to measuring biocidal activity, coating film quality as well as stability upon water immersion were evaluated. The results of the study showed that biocidal activity was strongly dependent on QAS concentration. For addition-curable coatings, the presence of 4 wt% QAS moieties resulted in approximately 50% reduction in C. lytica biofilm retention without any leachate toxicity. Attempts to increase the level of QAS moieties to increase biocidal activity resulted in coating delamination from the substrate and unacceptable film quality upon artificial seawater immersion due to excessive swelling. As a result, a moisture-curable system based on tethered QASs was investigated since moisture curing allows for higher crosslink densities to be achieved which would be expected to minimize swelling upon artificial seawater immersion. The moisture-curable coating developed showed enhanced stability upon artificial seawater immersion, greater than 80% reduction in C. lytica biofilm retention, and greater than 90% reduction in biofilm growth for the marine algae, Navicula incerta. Presented at 2007 FutureCoat! Conference, sponsored by Federation of Societies for Coatings Technology, October 3–5, 2007, in Toronto, Ont., Canada.     

Tuning of activity, induction period and polymer properties of double metal cyanide catalyzed ring-opening polymerizations of propylene oxide by using quaternary ammonium salts

Polymerizations of propylene oxide (PO) have been carried out by using double metal cyanide (DMC) catalyst prepared by reacting ZnCl₂ and K₃[Co(CN)₆] in the presence of tert-butyl alcohol (^tBuOH) as a complexing agent. The catalytic activity and the induction period for PO polymerizations catalyzed by DMC are tunable by using various quaternary ammonium salts (QAS) as external additives. The DMC/QAS binary catalyst improves polymer properties as well such as molecular weight, molecular weight distribution, viscosity, and unsaturation level.     

Cyanide ions transport from aqueous solutions by using quaternary ammonium salts through bulk liquid membranes

Extraction experiments were carried out to determine the suitable solvent and carrier type. Five different solvents and carriers were used and verified. Trichloromethane and tetraoctyl ammonium chlorides were found to be the most appropriate solvent and carrier type for this study. The coupled transport of cyanide ions in aqueous solutions through bulk liquid membrane (BLM) was investigated using various stirring speeds and temperatures. Cyanide ion transport through BLM technique was analyzed according to coupled non-steady state kinetics of two consecutive irreversible first order reactions. The influences of the kinetic parameters (k_1d, k_2m, k_2a, R_m^max, t_max, J_d^max, J_a^max) for the various stirring speeds in the system were established. The removal and recovery efficiencies of the cyanide ions transported from aqueous solutions in 360 min were 99.4 and 82%, respectively. As the stirring speed was increased, both the efficiency of transport and recovery of cyanide ions from aqueous solutions were increased. On the other hand, for maximum membrane entrance (J_d^max) and exit (J_a^max) fluxes the activation energies were calculated as 21.6 kcal/mol and 10.5 kcal/mol, respectively.     

季铵盐型抗菌纤维素纤维的辐射接枝聚合

固相表面接触抗菌材料应用于水的表面接触消毒是一项新的水处理技术,提高材料表面抗菌基团含量将有利于抗菌性能的提高。本研究采用直接辐射接枝和预辐射接枝两种方法,在纤维素纤维表面引入具有抗菌功能的季铵盐聚合物,详细探讨了两种辐射接枝聚合技术以及温度、时间、单体浓度、辐射剂量等具体辐射接枝聚合工艺参数对接枝聚合反应的影响。利用红外光谱（FTIR）、扫描电子显微镜（SEM）对接枝纤维素纤维进行了表征。结果表明,采用预辐射接枝技术可制得接枝率55%以上的高接枝率抗菌纤维素纤维。     

两种含羟基双季铵盐杀菌剂的合成与固定化

合成了可固定化双季铵盐1,5-双(二甲基烷基碘化铵)-3-戊醇(An,n为烷基侧链碳原子数,n=6、8、10、12、14、16、18)和4,5-双(二甲基烷基溴化铵)-1-戊醇(Bn)。通过比较性试验证明游离态A14和B12的各种抗菌特性(抗菌活性,对温度、pH等环境因素的稳定性)不但优于目前传统的单季铵盐洁尔灭(BAC)抗菌剂,而且抗真菌也优于噻苯咪唑(TBZ)。并初步证明了A14和B12的可固定性。     

高分子季铵盐型抗菌材料的制备

通过γ-氯丙基三甲氧基硅烷的偶联,将水溶性聚乙烯亚胺(PEI)接枝在纳米SiO2表面,随后分别用1-溴己烷和碘甲烷对接枝的PEI进行N-烷基化修饰,使PEI中的部分氨基转变成季铵盐,得到水不溶性QPEI/SiO2微粒。通过测定PEI/SiO2上PEI的接枝量,考察了各种反应条件对QPEI/SiO2微粒制备的影响规律。研究结果表明,纳米SiO2表面接枝PEI的适宜条件为:反应溶剂为DMF,反应温度90~100℃,反应时间8 h,氯丙基化SiO2与PEI质量比为4∶1,在此条件下制备的QPEI/SiO2微粒中PEI接枝量为14.8%。QPEI/SiO2微粒经甲基化修饰后,季铵盐含量由0.96%增加到3.37%,其抗菌性能显著增强。     

几种新型吡啶卟啉季铵盐化合物的合成

采用了以吡咯和吡啶甲醛为原料,二甲苯为溶剂,水杨酸为催化剂的新反应体系合成了meso-四（4-吡啶基）卟啉.再与不同链长的溴代烃作用,合成了3种新型吡啶卟啉季铵盐化合物.其结构通过元素分析、紫外可见光谱、红外光谱、核磁共振谱和质谱确证.     

Syntheses of long-chain quaternary ammonium salts from fatty alcohols by microwave irradiation

The phase-transfer catalysts, long-chain quaternary ammonium salts, were rapidly synthesized from fatty alcohols by the reactions with hydrogen halides in the presence of trialkyl amines under microwave irradiation. The catalysts could be widely applied in a variety of quick and new organic reactions, whether by conventional heating or under microwave irradiation. The reaction efficiencies under microwave irradiation were higher than those obtained with conventional heating.     

Synthesis of novel quaternary ammonium salts from 1, 2-benzothiazine derivatives

A series of novel 1,2-benzothiazine based quaternary ammonium salts were successfully prepared through different organic transformations. Products of all transformations and final salts were separated out and purified. The product yields were good to excellent for all transformations. Resultant 1,2-benzothiazine based cationic amphiphilic systems were stabilized using different counter anions. All final products were confirmed by ¹HNMR and ¹³CNMR analyses. 1,2-benzothiazine based quaternary ammonium salts have a potential to be employed as a phase transfer catalyst for various reactions in future.     

含有机反离子的双子季铵盐的合成与性能

以十二烷基二甲基叔胺、环氧氯丙烷和对甲基苯磺酸为原料,合成了一种反离子含有机酸根的异丙醇基双子季铵盐GC-S.通过正交实验优化了合成工艺.利用FTIR、1HNMR和ESI-MS对产物结构进行鉴定.在最佳反应时间为10 h、反应温度100℃、n(十二烷基二甲基叔胺):n(对甲苯磺酸)=2:1.00的条件下,合成的GC-S...     

Synthesis and antimicrobial activities of polysiloxane-containing quaternary ammonium salts on bacteria and phytopathogenic fungi

A series of dimethylaminopropyl benzyl chloride grafted polysiloxanes (PDMS-g-BCs) with tunable molecular weights and cationic content were synthesized, and the effect of polymer structure on the antimicrobial activities against bacteria (Escherichia coli (E. coli) and Staphylococcus albus (S. albus)) and phytopathogenic fungi (Rhizoctonia solani (R. solani) and Fusarium oxysporum f. sp. cubense race 4 (Foc4)) were systematically assessed. The antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC) against E. coli and S. albus by the broth dilution method, and the antifungal activity was measured by mycelia growth inhibition as well as by the MIC and minimum fungicidal concentration (MFC) values. The molecular weight and cationic content were major determinants of the activities of PDMS-g-BCs; when the molecular weight was approximately 2500 g/mol and the cationic content was approximately 20 mol% of the total siloxane units, PDMS-g-BCs gained strong antimicrobial activities toward both E. coli and Foc4, comparable to those of a commonly used broad-spectrum microbicide benzalkonium chloride, making PDMS-g-BCs promising fungicidal agents for plant disease control.     

Catalytic performance of quaternary ammonium salts in the reaction of butyl glycidyl ether and carbon dioxide

The synthesis of cyclic carbonate from butyl glycidyl ether (BGE) and carbon dioxide was performed in the presence of quaternary ammonium salt catalysts. Quaternary ammonium salts of different alkyl group (C₃, C₄, C₆ and C₈) and anions (Cl⁻, Br⁻ and I⁻) were used for this reaction carried out in a batch autoclave reactor at 60–120 °C. The catalytic activity increased with increasing alkyl chain length in the order of C₃ < C₄ < C₆. But, the quaternary ammonium salt with longer alkyl chain length (C₈) decreased the conversion of BGE because it is too bulky to form an intermediate with BGE. For the counter anion of the tetrabutyl ammonium salt catalysts, the BGE conversion decreased in the order Cl⁻ > Br⁻ > I⁻. The effects of carbon dioxide pressure and reaction temperature on this reaction were also studied to better understand the reaction mechanism.     

双烷基季铵盐的制备与杀菌性能研究

以溴代烷为原料制备了双烷基二甲基溴化铵系列产品。在产品制备的胺化步骤,作者彩和乙醇作为溶剂或加入相转移催化剂,明显缩短了合成时间,使产品双烷基二甲基溴化铵的产率得到了进一步提高。另外针对双烷基二甲茏溴化铵的杀菌性能进行了一系列评价实验,并与１２２７杀菌剂进行了对比。结果表明：双辛基二甲基溴化铵是较理想的杀菌剂,在较低的浓度下（３０ｍｇ／Ｌ）,其对硫酸盐还原菌（ＳＲＢ）及腐生菌（ＴＧＢ）的杀菌率达１     

含氟季铵盐的动态界面张力性能和润湿铺展性能的研究

含氟季铵盐表面活性剂是一类具有高表面活性、高耐热稳定性、高化学稳定性和憎水、憎油等特殊性能的表面活性剂。该文通过测定不同时间、不同种类的油相、不同质量分数的表面活性剂以及不同无机盐添加比例对油水界面张力的影响以及不同浓度的含氟季铵盐表面活性剂水溶液在石蜡、金属铁等不同固体表面上的接触角,对其动态界面张力以及润湿铺展性能进行了研究。结果表明：界面张力值通常在10min后基本达到平衡,且用渤61#油做油相时,界面张力值较低,效果比较好;随着表面活性剂质量分数的增加,界面张力先减小,达到一个最低值后渐渐趋于平缓;无机盐的加入使得界面张力先降后升,在NaCl质量浓度为50~80g/L内均降至低界面张力,最低值达到0.0531mN/m;同时,在典型的具有强疏水性的低能表面石蜡上的铺展性能优良。该研究为其在水溶性场合的应用提供了实验数据。     

Preparation and antimicrobial activity of terpene-based polyurethane coatings with carbamate group-containing quaternary ammonium salts

A series of novel carbamate group-containing quaternary ammonium salts (QASs) have been synthesized, which were subsequently used as antimicrobial agent and incorporated into polyurethane coatings through crosslinking with terpene-based polyol and polyisocyanate. The chemical structures of QASs were characterized by FT-IR, ¹H NMR, and ¹³C NMR. The effects of QASs on the properties of coatings were investigated. The results showed that the resulting coatings exhibited significant antimicrobial activity against both Staphylococcus aureus and Escherichia coli by introducing QASs into the polyurethane networks. Furthermore, with the increasing of QAS content, the antimicrobial activity and adhesion of the coatings were enhanced, while the pencil hardness, water resistance and thermal stability of the coatings were decreased.     

抗菌纤维素纤维对金黄色葡萄球菌的抗菌过程

通过表面接枝的方法,在纤维素纤维表面引入具有抗菌功能的季铵盐聚合物,考察了抗菌纤维对金黄色葡萄球菌的抗菌过程特性.接枝抗菌材料可在短时间内迅速降低溶液中细菌的活菌量.采用TTC活性和菌体耗氧测定法与扫描电镜观察法研究了抗菌过程.结果表明,其抗菌过程由吸附、抑制活性和破裂杀灭3个步骤构成,被抗菌纤维吸附的金黄色葡萄球菌不具有繁殖能力.     

Effect of small cation addition on the conductivity of quaternary ammonium ionic liquids

Several quaternary ammonium or lithium bis(trifluoromethane sulfone) imide (TFSI) salts were dissolved into N,N,N,N-hexyltrimethyl ammonium TFSI ionic liquid, and the conductivities of the resulting solutions were measured. Some asymmetric quaternary ammonium salts contributed to increase the conductivity of the solution, while cyano-containing quaternary ammonium and lithium salts decreased the conductivity. Based on the results of differential scanning calorimetry (DSC) measurements, such conductivity behaviors appeared to be related to the intrinsic miscibility of the ionic liquid solutions.     

Quaternary ammonium salts ionic liquids for immobilization of chiral Ru-BINAP complexes in asymmetric hydrogenation of β-ketoesters

Chiral catalytic complex (R)—[RuCl(binap)(p-cymene)]Cl was used in asymmetric hydrogenation of methyl acetoacetate to methyl-3-hydroxybutyrate in the mixed methanol-ionic liquid phase. Quaternary ammonium salts ionic liquids, namely n-alkyl-triethylammonium bis(trifluoromethane sulfonyl) imides (N_R222Tf₂N, R = 6, 7, 8, 10, 12, 14), were prepared and employed in this transformation. Enough evidence was provided that only a small amount of this type of IL in a conventional solvent was necessary to accommodate the catalytic complex and that the reaction could be carried out with very high enantioselectivity. Similarly it was proved that under optimized conditions the catalytic complex immobilized in this manner could be used repeatedly. A part of the work was focused on the role of the alkyl chain length in the N_R222Tf₂N ionic liquid which was found as very essential. Role of the reaction impurities with origin in the synthesis of the employed ILs was also investigated.     

Synthesis, structure, thermal and mechanical properties of nanocomposites based on linear polymers and layered silicates modified by polymeric quaternary ammonium salts (ionenes)

Polymer–clay composites has been prepared by melt blending an organo-bentonite with linear polymers (polyamide, polysterene and polypropylene) in a disk-screw extruder. In first time organo-clay was prepared by surface treatment of Na-forms bentonite with polymeric quaternary ammonium salts (PQAS). XRD indicated that organo-bentonite layers were exfoliated and dispersed into polyamide and polystyrene. Addition of 2 wt% organo-bentonites (optimal concentration) to polyamide increased tensile strength by 53% and Sharpy impact by 140%. With the incorporation of 2 wt% organo-bentonites (optimal concentration) into polystyrene the tensile strength increased to 28% and the Sharpy impact increased to 25%. For polypropylyne–organo-bentonites composites we did not observe delamination of layered structure, and as result absence of reinforcements. TGA showed that the polyamide and polystyrene nanocomposites have higher decomposition temperature in comparison with the original polymers.     

Synthesis and antimicrobial activities of acrylamide polymers containing quaternary ammonium salts on bacteria and phytopathogenic fungi

Three series of acrylamide monomers/polymers containing quaternary ammonium salts (QASs), i.e., acrylamide QAS monomers (QDs), homopolymers of QDs (PQDs) and copolymers of QDs with acrylate monomer (PQDCs), were synthesized and employed in antimicrobial tests against both bacteria (Escherichia coli (E. coli) and Staphylococcus albus (S. albus)) and phytopathogenic fungi (Rhizoctonia solani (R. solani) and Fusarium oxysporum f. sp. cubense race 4 (Foc4)). The antibacterial activity of the QASs was evaluated by determining the minimum inhibitory concentration (MIC) against E. coli and S. albus by the TTC coloration method, and the antifungal activity was measured by mycelia growth inhibition as well as MIC and the minimum fungicidal concentration (MFC) values. The results indicated that PQD homopolymers and PQDC copolymers showed far better antimicrobial activities than QD monomers. PQDC copolymers by incorporating hydrophobic acrylate units into the main chain of polyacrylamide backbone displayed even better antimicrobial activities, depending on QAS structure and hydrophobic content. Moreover, polymers with benzyl group attached to nitrogen atom showed better inhibitory effect on bacteria and phytopathogenic fungi. The results could assist understanding and development of future design of antimicrobial polymers as potential fungicide agents to control plant disease.