The New Quaternary Ammonium Salts With Organic Couterion And Its Compound Behavior

Quaternary ammonium salts (QAS) are versatile in many application fields including printing and dyeing, construction, mining industry, daily chemical industry, oil exploitation and etc., due to the positive charged character causing it special antimicrobial and anti-static properties. Nowadays,the QAS applies to industry applications and science research are usually containing traditional inorganic counterion, such as Cl-? Br- and CH3SO4-. However,with the development of industry and the technology progress, these traditional QAS are difficult to meet with the requirement of modern green chemical industry. It is the development trend to enhance the quality and profound the species of QAS. Nowadays, some research works have demonstrated that counterion influence the physicochemical and application properties of ionic surfactants, and the organic counterion have a more obvious impact on its properties. Therefore, the structure-activity relationship of counterion and properties in QAS need a further investigation. In addition, the industry application of surfactants commonly used in a mixed systems. To expand the application properties and fields, the compound systems of QAS with newly organic counterion (QAS-NC) should systematically investigated.This paper selects QAS with newly organic counterions (QAS-NCs) as research objects,which were synthesized by a green synthesis route from our research group. The structure-activity relationship between alkyl-chain-length of counterion and its physicochemical properties or application property were investigated. Furtherly, the surface activity,application properties, detergency and antimicrobial property in mixtures of QAS-NC with other surfactants were also studied. The main research contents are as the follows:(1) The surface adsorption and micelle aggregation behaviors of cetyltrimethyl quaternary ammonium salts are investigated. The surface tension measurement of QAS-NC indicates that surface tension parameters CMC, ycmc and Amin all have a regular of increasing firstly and then decreasing, while the parameters of ?CMC, pC20, CMC/C20 and tmax have the regular of the opposite. Interestingly,a same inflection point is observed when the chain length of the counterion is equal to 2 (C16NC2). Conductivity measurement shows the value of ?,?G0mic and ?G0ads have regular of decreasing first and increasing as the increasing alkyl-chain-length of counterion. The micelle aggregate number measurement shows the critical aggregates ([Nagg], aggregation number (Nagg) at CMC) decreases with the increasing alkyl-chain-length of counterion, but the Nagg at a higher concentration (5.0 X 10"3 mol/L,approximately to 5 times of CMC and above), which decreases first and then increases with the increasing alkyl-chain-length of the counterion in QAS-NC. The spontaneous forming vesicle structure is only observed in C16NC10 with a long chain length of counterion at a certain concentration, and also the theory calculation of packing parameter (P) confirm that C16NC10 is more likely to form vesicles in a certain condition. Dynamic surface tension demonstrates there exists different adsorption mechanism with the time: for short time,the monomer concentration and steric obstacle are the main driving force, but for long time, the surface potential energy barrier is the primary influence factor.(2) The application properties of QAS-NC are investigated, and it demonstrates that the wetting ability measured by dynamic contact angle enhanced as the increasing counterion alkyl-chain-length. The emulsification ability decrease first and then increase as the growth of counterion alkyl-chain-length in QAS-NC. The foam volume and its stability achieve the best when alkyl-length of counterion come to 6-8. The antimicrobial activity of QAS-NCs is mainly affected by the hydrophobic chain length of the cationic part, while the chain length of counterion has a limited influence on it. Only when the hydrocarbon chain length of cationic headgroup exceeds C12 does the QAS-NCs have an effective antibacterial activity(antibacterial rate > 50%),and the antibacterial activity of QAS-NC is slightly lower for the long chain counterions than that of the short ones. The minimum concentration for antibacterial rate of 100% (E. coil) is 50 mg/L (2 min). The antibacterial ability of QAS-NC to different bacteria or fungi has this order: Staphylococcus aureus (S. A.) = Monilia albican(M. A.) > Escherichia coli (E. coil) > Bacillus subtilis (B. S.) > Pseudomonas aeruginosa (P.A.).(3) The synergistic effect of the binary mixed surfactants containing C16NC1 has also been conducted. It indicates that the intermicellar interaction has the following order (from strong to weak): cationic/ anionic > cationic/nonionic (APG) > cationic/zwitterionic >cationic/nonionic (AEOn types, with polyoxyethylene ether (EO) structure). The stability measurement shows that the mixtures of cationic/nonionic and cationic/zwitterionic both have strong stability,but for anionic/cationic mixed system, the compatibility and stability of the anionic surfactants containing the EO structure are better than those without EO. In terms of anionic/cationic mixtures,the foaming ability decreased,but its stability of the foam and emulsifying performance and wetting property on parafilm surface enhanced (contact angle reduced). As for the cationic/nonionic mixed systems, its foaming ability increased,but its emulsifying performance and wetting property on parafilm surface decreased(equilibrium contact angle increased).(4) Finally, the detergency ability and antibacterial properties in mixtures of QAS-NC and other surfactants has been carried out. The detergent performance test shows that the mixed system which consists of the anionic or nonionic surfactants containing the EO structure and a small amount of C16NC1,has synergistic effect in washing ability for the carbon black soil cloth (JB-01) and the sebum cloth (JB-03). Besides the detergency ability is better than that of the standard detergent. Besides, the addition of small content (1%-3%) of QAS-NC to standard detergent has less influence on detergency performance of JB-01, but decrease the detergency ability as the increasing content of QAS-NC for JB-03. The antimicrobial activity of QAS-NC has less been affected within cationic/nonionic and cationic/zwitterionic systems,but there is no antimicrobial activity in cationic/anionic systems. Furtherly,it has demonstrated that the mixed-order has a significant influence on antibacterial activity among mixed system of anionic/ cationic/nonionic surfactants (nonionic as the main components),and the advisable mixing order is never mixed anionic and cationic surfactants together before addition other components.In summary, the surface activity and application properties increases with the increasing alkyl-chain-length of organic counterions of QAS-NC, and there is different extent of synergism effect on binary systems containing QAS-NC, but the application properties relates to the types of the mixtures; and it is feasibility to use QAS-NC as antibacterial agents in detergency product of both owing antibacterial and detergent ability.