溴烷铵改良膨胀土性能试验研究

针对膨胀土不利的工程特性,结合膨胀土地区路基边坡防护工程,采用溴烷铵进行膨胀土化学改良试验。试验研究改良土的液塑限、膨胀性、力学强度、水稳定性。结果表明,溴烷铵改良膨胀土的液限减小、塑限增加、塑性指数明显降低,自由膨胀率、膨胀力较素土有较大降低,膨胀速率减小,土体力学强度指标、地基承载力有明显提高,水稳定性显著改善。膨胀土地区路基边坡防护工程中,采用溴烷铵改良膨胀土工程性质,是较经济且施工简单的改良方法。

CTAB法制备超螺旋质粒DNA

研究了基因治疗用载体质粒DNA的一种非色谱的大规模纯化方法—CTAB沉淀法,并对其进行了工艺优化．首先采用高纯过滤介质CelPure去除大量杂质,并利用CTAB浓度梯度溶液研究了不同形式DNA(超螺旋质粒DNA、切口质粒DNA、线性质粒DNA、染色体DNA)沉淀能力的差异,选择性地从蛋白质、RNA及其他形式DNA中提取超螺旋质粒DNA．针对含有pcDNA3的DH5α菌株,确定CTAB完全沉淀超螺旋质粒DNA的浓度为2．0g/L,由NaCl对不同沉淀的溶解能力,确定溶解沉淀的最优盐浓度为0．75 mol/L．用此方法得到的超螺旋质粒DNA的纯度达90％以上,收率为78．94％．RNA、蛋白质残量以及内毒素均符合药品质量标准要求．CTAB对质粒DNA的沉淀效果与质粒DNA的初始浓度有关,并且超螺旋质粒DNA浓度的降低与CTAB的添加量呈一定的线性关系．超螺旋质粒的分子量越小越不易被分离,并且结构特性比分子量在分离过程中更据主导作用．

Binding tendency with oligonucleotides and cell toxicity of cetyltrimethyl ammonium bromide-coated single-walled carbon nanotubes

Functionalized carbon nanotubes （CNTs） were made for the delivery of genes and drugs and CNT-based biosensors. The basis of CNTs is for binding with biomolecules in biomedical applications. The binding tendency with small interfering RNA oligonucleotides and cytotoxicity of cetyltrimethyl ammonium bromide （CTAB）-coated single-walled carbon nanotubes （SWNTs） were studied. The field emission scanning electron microscopy and transmission electron microscopy results show that a SWNT suspension in CTAB solution was well-dispersed and stable. CTAB is the cross-linker between SWNTs and oligonucleotides. The CTAB-coated SWNTs have less cytotoxicity to human umbilical vein endothelial cells than single SWNTs and the cytotoxicity of CTAB-coated SWNTs depended on the concentration of CTAB-coated SWNTs.

Effect of cetyltrimethylammonium bromide on morphology and porous structure of mesoporous hydroxyapatite

The mesoporous hydroxyapatite （HA） was synthesized by hydrothermal method utilizing cationic surfactant cetyltrimethylammonium bromide （CTAB） as template. The crystalline phase, morphology and porous structure were characterized respectively by different detecting techniques. The results reveal that the particles are highly crystalline hydroxyapatite phase. The surfactant has little influence on the morphology of the crystals, but affects the porous structure obviously. The sample without CTAB has a low surface area not exceeding 33 m^2/g, and no distinct pores can be observed by TEM. While the samples obtained with the surfactant get better parameters. Numerous open-ended pores centered at 2-7 nm spread unequally on the surface of the hydroxyapatite nanorods. The N2 adsorption-desorption experiments show type IV isotherms with distinct hysteresis loops, illustrating the presence of mesoporous structure. When the mole ratio of CTAB to HA is 1：2, the sample has the largest surface area of 97.1 m^2/g and pore volume of 0.466 cm^3/g.

0.1%新洁而灭液消毒效力的初步探讨

目前医疗卫生单位大都采用0.1%新洁而灭溶液作为器械消毒剂。新洁而灭比酒精便宜,杀菌谱较广,对革兰氏阳性菌(G^+)及革兰氏阴性菌(G^-)如:葡萄球菌、伤寒、副伤寒、痢疾、大肠杆菌以及结核、芽胞、霉菌等均有杀灭效力而得以广泛应用。药液更换时间各不相同。以广西为例:有30天换一次,有15天的,也有7天的。我院是7天换一次。究竟多长时间更换为好?器械的数量及应用次数与灭菌效果之间关系如何?不同的科室有无差别?

Inclusion Complex of β-cyclodextrin with CTAB in Aqueous Solution

Cetyltrimethylammonium bromide （CTAB）/potassium bromide （KBr） micellar system has been used as a viscosity probe to study the inclusion complexation between β-cyclodextrin （β-CD） and CTAB. Viscosity measurements show that the inclusion complexation between β-CD and CTAB may cause the breakdown of CTAB/KBr wormlike micelles, resulting in the decrease of the solution viscosity. The viscosity minimum at Cβ-CD/CCTAB=2 indicate the molecular ratio of host molecule to guest molecule is 2：1 in the β-CD/CTAB inclusion complex.

Determination of Chlordiazepoxide by Sodium Tetraphenylboron Method

This paper describes an effective method for determining chlordiazepoxide. An excess of sodium tetraphenylboron is added to precipitate chlordiazepoxide in HAc NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate is titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied for the determination of chlordiazepoxide raw materials with satisfactory results. The recovery is between 99.58% and 100.4%, the relative error is less than ± 0.50% . Experiments show that the method gives the same results as the approach using nonaqueous titration (ChP).

Determination of Ciprofloxacin Lactate by Sodium Tetraphenylboron Method

This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate was titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied to the determination of ciprofloxacin lactate raw material with satisfactory results. The recovery was between 99.66% and 100.2%, the relative error was less than ±0.40%. Experiments showed that the method gave the same results as the approach using nonaqueous titration (ChP).

Cu(Ⅱ),Ni(Ⅱ)Complexation with Acid Alizarine Blue B in the Presence of Cetyltrimethylammonium Bromide

The coordination reactions of Cu（Ⅱ） and Ni（Ⅱ） with acid alizarine blue B （AABB） in the presence of cetyltrimethylammonium bromide （CTAB） micelle were investigated using the microsurface adsorptionspectral correction technique （MSASC）. The aggregation of AABB on CTAB followed the Langmuir isothermal adsorption law. The enrichment of AABB on CTAB sensitized the complexation between Cu（Ⅱ） or Ni（Ⅱ）and AABB. The binding ratio of AABB to CTAB was 1：2.5, and monomeric aggregate, AABB2CTAB5, was formed with an adsorption constant of 5.95×10^5 at 20 ℃ or 2.48×10^5 at 40 ℃. In the ternary complexation, the ratio of AABB：Cu and AABB：Ni were 1：1 and 1：2.5, respectively. Two types of aggregates, Cu2.AABB2·CTAB80 and Ni5.AABB2.CTAB80, were formed.

Synthesis and characterization of porous cobalt oxide/copper oxide nanoplate as novel electrode material for supercapacitors

A promising Co3O4/Cu O composite electrode material was successfully synthesized through a facile hydrothermal and calcination process. Effects of the surfactants hexadecyltrimethyl ammonium bromide（CTAB） and polyvinylpyrrolidone（PVP） on the morphology and electrochemical performance of the composite were investigated. Powder X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and nitrogen adsorption-desorption experiment were employed to characterize the microstructures and morphologies of the composite. Meanwhile, the electrochemical performances of the samples were studied using cyclic voltammetry（CV）, galvanostatic charge-discharge test and electrochemical impedance spectroscopy（EIS）. The results show that the porous Co3O4/Cu O-CTAB nanoplates own the best performance and exhibits a high specific capacitance of 398 F/g at 1 A/g with almost 100% capacitance retention over 2000 cycles, and it retains 90% of capacitance at 10 A/g.

铁氰化钾化学发光体系测定维生素B_1的研究

基于在NaOH碱性中，铁氰化钾可以直接氧化维生素Bl产生化学发光，而十六烷基三甲基溴化铵（CTAB）的存在可以大大增强这一化学发光强度，结合流动注射分析技术，在研究并优化化学发光条件的基础上，建立了测定维生素B1的化学发光分析方法。该方法测定VB1的线性范围为0．06-360mg／L，检出限（30）为0．045mg／L，对0．6mg／LVB1溶液连续11次平行测定的相对标准偏差为1．44％。该法已成功应用于维生素B1片剂及针剂中VB1的含量测定。

Synthesis, characterization, and catalytic performance of hierarchical ZSM-11 zeolite synthesized via dual-template route

Hierarchical zeolite materials were prepared via one‐pot synthesis of ZSM‐11zeolites with different molar ratios(R)of a mesoporogen,i.e.,cetyltrimethylammonium bromide template(CTAB),to a microporogen,i.e.,tetra‐n‐butylammonium bromide(TBABr).The structures,morphologies,and textural properties of the resultant materials were investigated.Initially,with increasing R,the crystal size of the synthesized product decreased,the number of intercrystalline mesopores increased,and a pure ZSM‐11zeolite phase was present.Then an MCM‐41‐like phase was produced and embedded in the ZSM‐11zeolite phase.Finally,an MCM‐41‐like phase was obtained.The alkalinity had important effects on the physicochemical and textural properties of the prepared samples.A possible mechanism of formation of the hierarchical ZSM‐11zeolite was proposed on the basis of a combination of various characterization results.The role of CTAB varied depending on the R value,and it showed a capping effect,micellar effect,and template effect.These effects of CTAB were synergetic in ZSM‐11synthesis,but they were competitive with the structure‐directing effect of TBABr.In addition,the impact of the acidic properties and porosities of the hierarchical ZSM‐11catalysts on their performances in the alkylation of benzene with dimethyl ether was investigated.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Mechanism of separating muscovite and quartz by flotation

Flotation experiments were performed to investigate the separation of muscovite and quartz in the presence of dodecylamine(DDA), tallow amine(TTA) and dodecyltrimethylammonium bromide(DTAC). The adsorption mechanisms of these three kinds of amines on muscovite and quartz were studied by FT-IR spectrum analysis, contact angle measurement and molecular dynamics(MD) simulation. The results reveal that the separation of muscovite from quartz is feasible at strong acid pulp condition using amine collectors. TTA and DTAC show poorer collecting ability for flotation of the two minerals compared with DDA. Physical adsorption is found to be the main adsorption module of amine collectors on muscovite and quartz by FT-IR analysis. MD simulation results show a strong physical adsorption ability of DDA+ cation on muscovite and quartz(muscovite(001):-117.31 kJ/mol, quartz(100):-89.43 kJ/mol), while neutral DDA molecular can hardly absorb onto the surface of these two minerals. These findings provide a novel explanation for the flotation mechanism from the perspective of MD simulation.

Cytotoxicity effect assessment of acid purified carbon nanotubes modified with cetyltrimethyl ammonium bromide

The cytotoxicities of single-walled carbon nanotubes （SWNTs） and acid purified single-walled carbon nanotubes （SWNT-COOH） were investigated by spectroscopic analysis. Cell viability and cell apoptosis were applied to assessing the cytotoxicity of SWNT-COOH, cetyltrimethyl ammonium bromide （CTAB） and acid purified carbon nanotubes modified with cetyltrimethyl ammonium bromide （SWNT-COOH/CTAB）. The results indicate that SWNTs are more toxic than SWNT-COOH. Concentration and time-curve analyses indicate that cytotoxicity of SWNT-COOH/CTAB is more related to the toxicity of the surfactant CTAB. The cytotoxicity effect of CTAB and SWNT-COOH/CTAB is acceptable at low concentrations （0.5-25μg/mL）. The cytotoxicity observation suggests that SWNT-COOH/CTAB can safely applied to biomedical field at low concentrations （0.5-25μg/mL）.

Sol-gel Transition of Methylcellulose Solution in the Coexistence of Hexadecyltrimethylammonium Bromide and Sodium Chloride

The sol-gel transition of methylcellulose （MC） solution in the presence of NaCl and hexade- cyltrimethylammonium bromide （HTAB）, together with MC/NaCl solution in the presence of HTAB and MC/HATB solution in the presence of NaCl, was investigated by the rheological measurements. It has been found that the sol-gel transition temperature of MC solution decreases linearly with the concentration of NaCl in solution but increases linearly with the concentration of HTAB in solution, respectively. However, the sol-gel transition temperature of MC/NaCl solution in the presence of HTAB keeps the same value, independent of the concentration of HTAB in solution. On the other hand, the sol-gel transition temperature of MC/HTAB solution decreases linearly with the concentration of NaCl in solution. The experimental results suggest that, for MC/NaCl solution in the presence of HTAB, the salt- induced spherical micelles of HTAB should have formed in bulk solution. For MC solution in the absence of NaC1, no spherical micelles have been formed in bulk solution, though the concentration of HTAB in our experiment is almost one order of magnitude higher than the critical mieelle concentration of HTAB in polymer-free solution. In fact, due to adsorption of HTAB on MC chains, the realconcentration of HTAB in bulk solution, is much less than the apparent concentration of HTAB dissolved in MC solution.

Thermal stability and long-acting antibacterial activity of phosphonium montmorillonites

Na-montruorillonite （Na-MMT） was exchanged with three quaternary atkylphosphonium salts： decyl tributylphosphonium bromide （DTBPBr）, dodecyl tributylphosphonium bromide （DDTBPBr） and hexadecyl tributylphosphonium bromide （HDTBPBr）, to investigate the effects of phosphonium salts species and relative molecular mass on the characteristics, morphology, thermal stability and long-acting antibacterial property of phosphonium montmorillonites. The resulting modified montmorillonites were characterized by the FTIR, XRD, TEM, and TG/DTG techniques. And minimum inhibitory concentration （MIC） was used to investigate antibacterial activity. The results show that the phosphonium salts are intercalated into Na-MMT, and the basal spacing of P-MMTs is enlarged with the increase of phosphonium salt content or the growth of alkyl chain length. DDTBP-MMT-3 with 19.83% （mass fraction of dodecyl tributylphosphonium salts, displays excellent thermal stability and long-acting antibacterial activity.

Selective Affinity Separation of Yeast Alcohol Dehydrogenase by Reverse Micelles with Unbound Triazine Dye

The reversed micelles were formed with cationic cetyltrimethylammonium bromide (CTAB) as surfactant and n-hexanol as cosolvent in the CTAB (50mmol.L-1)/hexanol (15% by volume)/hexane system. Cibacron Blue 3GA (CB) as an affinity ligand in the aqueous phase was directly introduced to the reversed micelles with electrostatic interaction between anionic CB and cationic surfactant. High molecular weight (Mr) protein, yeast alcohol dehydrogenase (YADH, Mr = 141000) from baker's yeast, has been purified using the affinity reversed micelles by the phase transfer method. Various parameters, such as CB concentration, pH and ionic strength, on YADH forward and backward transfer were studied. YADH can be transferred into and out from the reversed micelles under mild conditions (only by regulation of solution pH and salt concentration) with the successful recovery of most YADH activity. Both forward and backward extractions occurred when the aqueous phase pH＞pI with electrostatic attraction between YADH and CTAB. The recovery of YADH activity and purification factor have been improved with addition of a small amount of affinity CB. The recovery of YADH activity obtained was ～99% and the purification factor was about 4.0-fold after one cycle of full forward and backward extraction. The low ionic strength in the initial aqueous phase might be responsible for the YADH transfer into the reversed micellar phase.

利用RAPD标记鉴定山葡萄种质

采用修改后的CTAB法获得了高质量的基因组DNA.利用随机扩增多态性即RAPD标记对山葡萄7份种质进行鉴定,用4个引物(从30个引物中筛选)对试材进行PCR扩增,共扩增出30条谱带,平均每条引物产生7.5条谱带,其中21条谱带为多态性谱带,占总谱带数的70%.不同引物扩增的谱带数不同,范围在6～9条之间.利用4个引物扩增出的多态性谱带可以将7份山葡萄种质区分.

Adsorption of sulfate in aqueous solutions by organo-nano-clay:Adsorption equilibrium and kinetic studies

The adsorption of sulfate in aqueous solutions onto organo-nano-clay prepared by natural zeolite and cationic surfactant cetyltrimethylammonium bromide （CTAB） was studied.Parameters such as adsorbent dosage,contact time and temperature were investigated using batch adsorption studies.The results show that the uptake of sulfate increases with the increase of contact time and temperature,and decreases with the increase of dosage.The Freundlich isotherm model is fit to explain the sulfate adsorption onto organo-nano-clay.The maximum adsorption capacity is found to be 38.02 mg/g at 40 ℃.The kinetic data fit well the pseudo-second-order and Elovich models with a R2 more than 0.98.It is suggested that chemisorption is the rate-controlling step for adsorption of sulfate onto organo-nano-clay,meanwhile both intraparticle diffusion and boundary layer diffusion also contribute as well.Ion-exchange between sulfate anions and bromide ions and complexation between sulfate anions and CTAB cations are responsible for the mechanism of sulfate adsorption.Keywords：organo-nano-clay; cetyltrimethylammonium bromide （CTAB）; modification; sulfate; adsorption

Membrane preconcentration of iron in seawater samples and on-site determination in spectrophotometry

A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe（II）-ferrozine complex was reacted with cetyltrimethylammonium bromide （CTAB） to form a Fe（II）-ferrozine-CTAB paired compound, which was collected on a membrane by filtration under vacuum. The membrane was immersed in 2 mL of ethanol-nitric acid and the absorbance of the solution measured for quantitative analysis. Various factors affecting the iron collection and determination were investigated. With different sample preconcentration volumes, the range of determination was broadened to 0.5-120 ~tg/L. The detection limit of this method reached 0.19 ktg/L and the recoveries were between 97.2 and 109% when the concentration enrichment was about 45. The relative standard deviation （n = 7） was 1.9% for samples containing 10 ~g/L Fe. Twelve seawater samples were analyzed on-site using the proposed method, and two were also analyzed in inductively coupled plasma mass spectrometry. No significant difference was shown between the two methods by the Student＇s t-test. The method has also been used on-site for iron enrichment experiments with phytoplankton and concluded to be simple, accurate and inexpensive.