Effect of quaternary ammonium salts on flotation behavior of aluminosilicate minerals

The electrokinetic properties and flotation of diaspore, kaolinite, pyrophyllite and illite with quaternary ammonium salts collectors were studied. The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order（from strong to weak） ofoctadecyl dimethyl benzyl ammonium chloride（ODBA）, cetyl trimethyl ammonium bromide（CTAB）, dodecyl trimethyl ammonium chloride（DTAC）. Under the condition of alkalescence, it is possible to separate the diaspore from the silicate minerals such as kaolinite, illite and pyrophyllite using quaternary ammonium salts as collector. Isoelectric points （IEP） of diaspore, kaolinite, pyrophyllite and illite are pH=6.0, 3.4, 2.3 and 3.2, respectively. Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously. The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum （FT-IR） measurements. The results demonstrate that only electrostatic interaction takes place between aluminosilicate minerals （diaspore, kaolinite, pyrophyllite and illite） and quaternary ammonium salts.

Flotation and adsorption of quaternary ammonium salts collectors on kaolinite of different particle size

The flotation behaviors of decyltrimethylammonium (103C), dodecyltrimethylammonium chloride (DTAC), tetradecyltrimethylammonium chloride (TTAC) and cetyltrimethylammonium chloride (CTAC) on kaolinite of different particle size fraction were studied. The adsorbed amount and adsorption isotherms of collectors on kaolinite were determined for painstaking investigation into the adsorption of quaternary amines at kaolinite-water interface by ultraviolet spectrophotometer methods. The flotation results show that the flotation recovery of kaolinite of different particle fraction increases with an increase in pH when 103C, DTAC, TTAC and CTAC are used as collectors. As the concentration of collectors increases, the flotation recovery increases. Particle size of kaolinite has a strong effect on flotation. The flotation recovery of fine kaolinite decreases with the carbon chain of quaternary ammonium salts collectors increasing, while coarse kaolinite is on the contrary. The adsorbed amount tests and adsorption isotherms show that adsorbed amount increases when the particle size of kaolinite increases or when the carbon chain length of quaternary ammonium salts increases. Within the range of flotation collector concentration, the longer the hydrocarbon chain, the more probable to be absolutely adsorbed by fine kaolinite particles and then the lower the collector concentration in the bulk, which leds to lower flotation recovery.

Aluminum-silicates flotation with quaternary ammonium salts

The zeta potential measurements show that the flotation separation of diaspore from kaolinite, illite and pyrophyllite could be achieved in the range of pH 46.5 with cationic collectors. A special quaternary ammonium salts(DTAL) shows better selectivity than that the dodecyl amine(DDA) does for the flotation of three silicates. The closed circuit flotation results show that the reverse flotation de silicate can be achieved with DTAL as collector, a new inorganic reagent(SFL) as depressant and MIBC as frother to obtain a bauxite concentrate m (Al 2O 3)/ m (SiO 2) >10, Al 2O 3 recovery>86%).

Synthesis of Chitosan Quaternary Ammonium Salts

A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiffs base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, (HNMR)-H-1 and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.

Wettability alteration of organo-vermiculites induced by layer charge and tailored bis-N-heterocyclic quaternary ammonium salts

Wettability is an important surface property that deserves to further explore the factors on its alteration.Series of bis-N-heterocyclic quaternary ammonium salts with different spacer length and N-heterocyclic headgroups(morpholinium(BMMB,BMMD and BMMH),piperidinium(BPMH)and piperazinium(BMPMH))have been synthesized and employed for altering the wettability of vermiculite and its derivates(Vts)treated by Li^(+)-saturated heating method.The results of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TG-DTG),scanning electron microscopy(SEM)and N_(2)adsorption/desorption isotherms indicate that all of the bis-N-heterocyclic quaternary ammonium salts have been successfully inserted into the vermiculite layers,leading to the organic monolayer.The results of capillary rise tests combined with Lipophilic to Hydrophilic Ratio(LHR)values unveil the wettability alteration of the organo-Vts.As the layer charge decreases,the hydrophilicity of the organo-Vts gradually increases,which is probably caused by the decline in binding sites.As the result of the change in spacer length of modifier,the wetting properties of morpholinium-based organo-Vts change in order of BMMD-Vts>BMMH-Vts>BMMB-Vts,and difference in N-heterocyclic headgroups leads to the sequence of wettability:BMPMH-Vts>BPMH-Vts>BMMH-Vts.Layer charge of Vt,spacer length and the type of the N-heterocyclic headgroup of modifier have the synergistic effect on the regulation of the wettability.

Biodegradable Quaternary Ammonium Salts for Processing Iron Ores

Two biodegradable quaternary ammonium salts were synthesized and used as cationic collectors in processing iron ores by froth flotation. The flotation behaviors of iron minerals with the new biodegradable quaternary ammonium collectors were investigated by micro-flotation tests of quartz (SiO2) and magnetite (Fe3O4). It was observed that the new biodegradable collectors were effective in separating quartz from magnetite by flotation. At the collector concentration of 1 × 10﹣4 mol/L, the recovery of quartz using the M301 and M302 collectors can reach its maximum of 67.97% and 91.18%, respectively. For a wide pH range, they also show good selectivity. By the measuring zeta potentials of the new quaternary ammonium salts, the results show that quaternary ammonium salt is preferred to adsorb on the surface of quartz. The two quaternary ammonium collectors are also determined as readily biodegradable collectors, according to the OECD301B evaluation standard.

Studies on a Cationically Modified Quaternary Ammonium Salt of Lignin

A new quaternary ammonium salt monomer was synthesized and a quaternary amination of lignin（ noted as QL）, with the monomer was carried out by grafting copolymerization. The products were characterized by Fourier Transform Infrared spectroscopy（ FTIR）. The experimental results indicate that the yield of the monomer was 99.06%, and the conversion of the monomer and the grafting yield of QL were 93.69% and 185.78%, respectively. The feasibility of QL as the flocculant to be applied in color removal of five artificial dyes, erioehrome black T（dye A）, gongo red（dye B ）, direct fast black G （dye C ）, cuprofix blue green B （dye D ）, and acid black ATT （dye E ） was examined. Results show that OL exhihits the favorable flocculation nerformance and high stability.

Superoxide Anion Radical Scavenging Ability of Quaternary Ammonium Salt of Chitosan

A series of N-alkyl or N-aryl chitosan quaternary ammonium salt were prepared using 96% deacetylated chitosan. Their scavenging activities against superoxide anion radical were investigated by chemiluminescence. The IC50 values of these compounds range from 280 to 880 μg/mL, which should be attributed to their different substitutes.

Dimethyl carbonate synthesis via transesterification catalyzed by quaternary ammonium salt functionalized chitosan

A quaternary ammonium salt covalently linked to chitosan was first used as a catalyst for dimethyl carbonate （DMC） synthesis by the transesterification of propylene carbonate （PC） with methanol. The effects of various reaction variables like reaction time, temperature and pressure on the catalytic performance were also investigated. 54% DMC yield and 71% PC conversion were obtained under the optimal reaction conditions. Notably, the catalyst was able to be reused with retention of high catalytic activity and selectivity. Consequently, the process presented here has great potential for industrial application due to its advantages such as stability, easy preparation from renewable biopolymer, and simple separation from products.

Preparation of spiro-type quaternary ammonium salt via economical and efficient synthetic route as electrolyte for electric double-layer capacitor

A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-dibromobutane and pyrrolidine, and subsequent ion exchange pathway with KOH followed by neutralization reaction via HBF4 in the system of ethanol solution. 1H NMR, 13 C NMR, FI-IR and XPS analyses showed the structure of SBP-BF4. The as-obtained SBP-BF4 was dissolved in AN and used as the electrolyte for supercapacitor. Electrochemical measurements demonstrate that, compared with commercial electrolyte TEMA-BF4/AN, SBP-BF4/AN exhibits high ionic conductivity, lower resistance and improved cycling performance, which is due to its smaller ion size and stable symmetry structure.

Preparation of Mesoporous ZSM-5 Zeolite under Double Ester Base Long Carbon Chains Organosilane Quaternary Ammonium Salt Template Agent

The pore sizes of traditional zeolites are in the range of0. 3-1. 5 nm,which strongly hinder the diffusion of large reactant and product molecules within the zeolite pores. To compensate for it,we tried to create mesopores in traditional microporous zeolites and retain all advantages of microporous zeolites. Mesoporous Zeolite Socony Mobile-Five( ZSM-5) zeolite was synthesized by a new double ester base long carbon chains organosilane quaternary ammonium salt as the soft template agent in hydrothermal method.The structure of the acquired zeolite crystals was confirmed by fieldemission scanning electron microscopy( FE-SEM), transmission electron microscopy( TEM), nitrogen adsorption-desorption measurements and X-ray diffraction( XRD),which indicated that their structure had the same characteristics as traditional ZSM-5 zeolites. Compared with traditional ZSM-5 zeolite,there were 4 nm and 15 nm mesopores in the crystal. The prepared hierarchical porous ZSM-5 zeolite was expected to be effective catalytic materials for chemical reactions involving large molecules.

POLYMER-SUPPORTED SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS AS CATALYSTS FOR PHASE-TRANSFER REACTIONS

In this study was to investigate, by phase-transfer catalysis, the activity of single and mixed ammonium and phosphonium salts grafted on a 揼el-type?styrene-7% divinylbenzene copolymer in the oxidation of benzyl alcohol with hydrogen peroxide. A wide variety of catalysts with different quaternary groups and different quaternary chain length substituents were examined. The activity of single 搊nium?salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support. The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the onium and of the functionalization degree with phosphonium groups.

ANTIBACTERIAL ACTIVITY OF SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS GRAFTED ON "GEL-TYPE" STYRENE-DIVINYLBENZENE COPOLYMERS

A systematic study on the synthesis and antibacterial activity of the quaternary "onium" salts grafted on an insoluble "gel-type" styrene-7% divinylbenzene copolymer by polymer-analogous reactions is showed. Antibacterial activity of quaternary ammonium and/or phosphonium salts grafted on polymer-supports has been studied against Staphylococcus aureus and Escherichia coli. A wide variety of "onium" salts bound to macromolecular supports with different quaternary groups and different quaternary chain length substituents were examined. The antibacterial activity of mixed "onium" salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support.

PREPARATION AND PHOTOSENSITIVITY OF WATER SOLUBLE PHENOLIC RESINS CONTAINING ACRYLOYL AND QUATERNARY AMMONIUM CHLORIDE GROUPS

New water soluble and photocrosslinkable prepolymers containing acrylate and quaternary ammonium salt groups were synthesized from epoxy phenolic resin via ring-opening reaction with acrylic acid and with aqueous solution of triethylamine hydrochloride successively. The second reaction needs no phase transfer catalyst to accelerate, since the product formed can act as a phase transfer catalyst. The prepolymer obtained contains both photocrosslinkable acrylate groups and hydrophilic quaternary ammonium salt groups. Optimum conditions for these reactions were studied. The photosensitivity of the prepolymer was also investigated. The effects of different photoinitiators, different crosslinkable diluent monomers and amine accelerator on the photosensitivity of the prepolymer were compared. The photoinitiator of hydrogen abstraction type is still effective without using amine or alcohol as accelerator, because the prepolymer contains a H beside the OH groups formed in the ring-opening reactions.

GO-QAS/棉复合纱线的构建及其性能

针对现有抗菌纺织品加工方法存在问题,利用静电纺喷技术,将接枝有机硅季铵盐的氧化石墨烯(GO-QAS)均匀喷射在棉网表面,经后序集聚加捻,构建GO-QAS/棉复合纱线。结果表明:当纺丝电压为35 kV、棉网厚度为3 mm、GO-QAS质量浓度为4 mg/mL时,GO-QAS在静电力作用下能够稳定喷射在棉网表面,同时GO-QAS包裹卷绕在棉纤维表面;进一步集聚加捻获得的GO-QAS/棉复合纱线也显示了优异的力学性能,并对大肠杆菌和金黄葡萄球菌具有大于99.99%的抗菌性。基于静电纺喷工艺路线,通过对氧化石墨烯不同的功能改性,还可制备多重功能因子组合的复合纱线,从而实现纱线的多功能改性。

QAX224捕收剂反浮选分离一水硬铝石和高岭石的试验研究

通过浮选试验、动电位和红外光谱测定,考察了以季铵盐QAX224为捕收剂,淀粉为抑制剂,一水硬铝石与高岭石反浮选分离的作用效果和机理。浮选试验表明,在pH=8～9的范围内,随着抑制剂用量的增加,一水硬铝石几乎全部被抑制,而高岭石则可出现轻微的活化作用。将一水硬铝石和高岭石的人工混合矿反浮选试验后,铝硅比提高到30.79。机理分析表明,捕收剂和抑制剂与高龄石除了物理作用,还出现了化学键合,一水硬铝石与捕收剂主要为静电吸附,与淀粉主要是化学吸附。

有机硅季铵盐HSQA的合成及性能研究

以十二烷基叔胺、γ-氯丙基三甲氧基硅烷为原料,合成了3-(三甲氧基硅烷基)丙基十二烷基二甲基氯化铵(HSQA),并用硝酸银滴定其产率;讨论了反应温度、反应时间、溶剂种类、反应物物质的量比对产率的影响.优化反应条件为:n(十二烷基叔胺)∶n(γ-氯丙基三甲氧基硅烷)为1.1∶1,120℃反应9 h,溶剂为N,N-二甲基甲酰胺与异丙醇的混合溶液,KI为催化剂.测定产物的表面张力,并用红外光谱研究合成产物结构.

季铵盐端氨基超支化聚合物HBP-QAC改性蚕丝织物的研制及用真菌色素染色的性能

用端氨基为季铵盐的超支化聚合物HBP-QAC对蚕丝织物接枝改性,以利于改善蚕丝织物使用真菌色素染料染色的性能。以染色K/S值为考核指标,进行HBP-QAC对蚕丝织物改性工艺条件的单因素优化试验,得到较佳的改性工艺条件为：改性剂HBP-QAC用量8 g/L,碳酸钠用量1.5 g/L,改性温度50℃,改性时间40 min。蚕丝织物在此工艺条件下用HBP-QAC进行改性后,可以明显提高其用银杏叶内生真菌分泌的红色素染色的K/S值,且耐皂洗色牢度和耐日晒色牢度提高至3级,耐摩擦色牢度提高至4-5级。利用动态光散射纳米粒度仪及Zeta电位分析仪测定改性后蚕丝织物表面的Zeta电位由-7.18提高到19.98,由于蚕丝织物表面的正电荷增加,使其与真菌色素染料之间的离子键作用力增强,所以染色K/S值及色牢度提高。

Modified gelatin with quaternary ammonium salts containing epoxide groups

An EPDDMAC-GE polymer （hydrophilic molecule） has been synthesized based on epoxypropyl dodecyl dimethyl ammonium chloride （EPDDMAC） and gelatin. A DEEPSAC-GE polymer （hydrophobic molecule） has been synthesized based on diethyl-2,3-epoxypropyl-[3-methyldimethoxyl] silpropyl ammonium chloride （DEEPSAC） and gelatin. Compared with initial gelatin, the gelatin modified with quaternary ammonium salts containing epoxide groups exhibits stronger antibacterial activity.

Synthesis of chiral spirocyclo-quaternary ammonium salts from L-proline and their application as phase-transfer catalysts in asymmetric alkylation

A new series of chiral phase-transfer catalysts 7a-7h were designed and synthesized from L-proline with moderate to good yields.＇The catalytic activity of 7a-Th for the asymmetric alkylation of glycine Schiff bases was evaluated, and some interesting relationships between structure and catalytic activity were revealed.