不同表面活性剂对电喷镀Ni-P-β-SiC层的影响

不同的表面活性剂影响着Ni-P-β-SiC镀液中β-SiC微粒的团聚程度,进一步影响了金属与β-SiC的共沉积过程,最终反映在复合镀层的表面质量上。研究了聚乙烯醇(PVA-1750)、十二烷基苯磺酸钠(SDBS)、聚乙二醇(PEG-6000)、十六烷基三甲基溴化铵(CTAB)、十二烷基硫酸钠(SDS)等5种表面活性剂对电喷镀Ni-P-β-SiC复合层的影响。通过计算表面活性剂的亲水、疏水平衡值(HLB),检测镀液中β-SiC微粒的Zeta电位、Ni-P-β-SiC镀液的极化曲线、Ni-P-β-SiC复合镀层的显微硬度,对不同表面活性剂进行了综合评价。结果表明:在含十二烷基苯磺酸钠(SDBS)的Ni-P-β-SiC镀液中,β-SiC微粒的Zeta电位绝对值最大、镀液的极化度高,β-SiC微粒的团聚程度最小,相应的复合镀层的显微硬度最高,其HLB值也符合β-SiC微粒结构的要求。     

Thermal and mechanical properties of polyamide 11 based composites reinforced with surface modified titanate nanotubes

The preparation of polyamide 11 (PA11) based composites reinforced with pristine and surface-modified titanate nanotubes (TTNT) is reported. Twin-screw melt compounding was used to produce composites with up to 2 wt% of TTNT. To enhance dispersion and TTNT compatibility with the thermoplastic, these were modified with cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS). Fourier transform infrared spectroscopy and thermogravimetry were used to demonstrate that surface modification prior to composite processing was successful, while scanning transmission electron microscopy combined with energy-dispersive X-ray analysis confirmed the retention of surfactants on TTNT in composites. Nevertheless, scanning and transmission electron microscopy revealed incomplete dispersion of TTNT inside polyamide. The improved wettability on the TTNT–PA11 interface was observed for composites comprising surface-modified TTNT. Consequently, these composites exhibited better thermal and mechanical properties than those containing pristine TTNT. A significant rise of the decomposition temperature was detected in composites containing TTNT modified with CTAB, while the uppermost increment of the storage and Young’s modulus (of about 35% and 26%, respectively) was achieved in the composite comprising 0.5 wt% of TTNT modified with SDS. The increase of the nanofiller content improved the yield strength and led to the drop in the strain at break.     

表面活性剂对羟基磷灰石纤维形貌的影响

以Ca(NO₃)₂·4H₂O和(NH₄)₂HPO₄水溶液为前驱体, 采用水热均相沉淀法制备了结晶度较高的羟基磷灰石纤维, 研究了表面活性剂十六烷基三甲基溴化胺(CTAB)、十二烷基硫酸钠(SDS)和聚乙二醇(PEG)及其含量对产物形貌和相组成的影响。结果表明, 采用这三种表面活性剂制备的产物都是羟基磷灰石, 部分样品含有少量碳酸钙杂质。加入CTAB和SDS均会对纤维的生长起到抑制作用, 得到纤维与球形团聚体并存的产物, 而PEG的加入在一定程度上促进了纤维的生长。     

Preparation and characterization of polypropylene/sodium propionate (PP/SP) composite films for bread packaging application

To prolong the shelf life of bread, polypropylene/sodium propionate (PP/SP) composite films were prepared via a melt‐extrusion process. To investigate the feasibility of using PP/SP composite films as a bread packaging material, their chemical structure, morphology, mechanical properties, barrier properties against water, surface properties, and antimicrobial properties were investigated. A storage test for bread was also conducted. The mechanical and thermal stability of the PP/SP composite films enhanced with increasing SP content. Compared with pure PP, the PP/SP composites had increased hydrophilicity that increased with increasing SP content. These composite films showed enhanced antimicrobial activity against both Gram‐negative and Gram‐positive microorganisms. This was due to the interaction of SP and water originating from the bread, which modifies the pH of the bread and causes destruction of the cellular structures of fungi and also reduces the growth rate of bacteria. The enhanced thermal, mechanical, antifungal, and antimicrobial properties achieved by the addition of SP can be beneficial for maintaining the freshness of bread and prolonging its shelf life.     

Synthesis and conductive properties of polypyrrole nanocomposites

This paper studies the impact on the different surfactants and capacity of the oxidant for the synthesis of polypyrrole (PPy). The soluble PPy has also been studied. PPy was characterized mainly from the surface morphology, Fourier transform infrared spectroscopy, and conductivity sigma. First, using cetyltrimethylammonium bromide (CTAB) as the surfactant doped in an acid doping environment and without using ammonium persulfate (APS) as an oxidant, we determined the different capacities of the oxidant to synthesize the PPy. Scanning electron microscopy, Fourier transform infrared spectroscopy, and a four-probe conductivity meter were used to characterize the PPy. The acid doping conductivity was found to be 25 S/cm higher. Then, the solubility of polypyrrole was studied by doping with sodium dodecyl benzene sulfonate (SDBS), polyethylene glycol (PEG), and poly(styrene sulfonate) (PSS), proceeding the above-mentioned characterization.     

树枝状与球状PbS纳米结构的组装合成及其形成机理研究

以醋酸铅为铅源,硫代乙酰胺为硫源,在表面活性剂SDS单独作用和表面活性剂SDS和CTAB共同作用下可选择性地组装合成出颗粒以相同晶面粘连组装成的单晶树枝状PbS纳米结构和颗粒以不相同晶面粘连组装成的多晶球状PbS纳米结构,而且提高反应物浓度能起到调节树枝状和球状PbS纳米结构尺寸的作用.对树枝状和球状PbS纳米结构的形成机理进行了初探,发现SDS单独作用时其烷基链起到的软模板作用有利于PbS小颗粒组装成树枝状的PbS纳米结构.当反应溶液中再加入适量的CTAB时,它在溶液中形成微胶束起到了软模板作用,迫使颗粒粘连组装成球状PbS纳米结构,有效地限制树枝状结构的生长.     

High performance natural rubber/thermally reduced graphite oxide nanocomposites by latex technology

The latex technology is an innovative alternative for the preparation of composites of natural rubber (NR) and thermally reduced graphite oxide (TRGO). To achieve an improvement of material properties is indispensable to prepare stable suspensions of TRGO. In this work the influence of two surfactants, such as sodium dodecyl sulfate (SDS), as ionic, and Pluronic F 127 as non-ionic surfactant, on the dispersion of TRGO in NR latex and the mechanical and physical properties of the composites were studied. The results showed that the SDS surfactant is ideal for preparing latex NR/TRGO nanocomposite. An optimum dispersion of the nanoparticles in the polymer matrix was achieved in the presence of SDS, as reflected in a considerable improvement of the physical and mechanical properties of the material. Thus, the nanocomposites with 3 phr of TRGO exhibited an improvement of nearly 400% in the maximum strength and an electrical percolation threshold with values around 10⁻⁶ S/cm, above the static limit.     

超声诱导CTAB/SDS溶液中纳米Pd粒子的形貌控制及对甲醛的电催化氧化

在十六烷基三甲基溴化铵(CTAB)-十二烷基硫酸钠(SDS)混合乙醇水溶液中,超声辐射PdCl2,合成了纳米Pd粒子,用XRD、TEM、选区电子衍射(SAED)、HRTEM和低温氮吸附-脱附等技术进行了表征,考察了CTAB/SDS组成对纳米粒子形貌的影响,纳米Pd粒子修饰玻碳电极对甲醛的电催化活性也通过循环伏安法进行了研究。结果表明:通过改变CTAB/SDS组成可以调控纳米Pd粒子的粒径和形貌;当CTAB与SDS物质的量之比为1∶1、超声反应60min时,得到呈多边形的纳米Pd粒子,粒径范围在10～20nm之间,比未添加表面活性剂样品的比表面积增大了14m2.g-1,对甲醛有较高的电催化活性。     

BaTiO3–P(VDF-HFP) nanocomposite dielectrics—Influence of surface modification and dispersion additives

We report on BaTiO₃–polymer composites as dielectrics for film capacitors. BaTiO₃ was synthesized by a sol–gel soft-chemistry method leading to spherical nanoparticles with a high degree of surface hydroxyl groups which turned out to be important for the bonding of surfactant molecules. As surfactants, n-octylphosphonic acid and 2,3,4,5,6-pentafluorobenzyl phosphonic acid were used to inhibit particle agglomeration and to improve the wetting behaviour with the polymer. The phosphonic acid-coated BaTiO₃ nanoparticles were dispersed in solutions of poly(vinylidefluoride-co-hexafluoropropylene). Composite films were prepared by the spin-coating technique. A systematic study was performed on the influence of varying oxide fractions, different surfactants and the effect of additional dispersion aids such as sodium dodecyl sulphate or BYK-W 9010 on the quality and dielectric properties of the films obtained. The chemical adjustment of the 2,3,4,5,6-pentaflourobenzyl phosphonic acid within the fluorinated organic host form a more uniform particle distribution and increase relative permittivity of the resulting composite material compared to the unflourinated surfactant. Additionally, an enhancement of the relative permittivity can be realized by adding of dispersants. These two components can increase the relative permittivity by factor 5 compared to the pure polymer material.     

纳米TiO2/涤纶海岛丝针刺无纺布光催化复合材料的制备及性能

以德固赛P25纳米TiO₂为光催化材料、去离子水为介质,分别以十二烷基硫酸钠（SDS）、十二烷基苯磺酸钠（DBS）、聚乙烯毗咯烷酮（PVP）、十六烷基三甲基溴化铵（CTAB）、聚丙烯酸钠（PAAS）为分散助剂,制得系列纳米TiO₂光催化分散液。用纳米TiO₂光催化分散液对涤纶海岛丝针刺无纺布（PFN-NWF）进行二浸二轧后整理,得到TiO₂负载的PFN-NWF （TiO₂/PFN-NWF）光催化复合材料。采用激光粒度仪、TEM、SEM、拉伸、透气等表征测试,通过静置、光催化降解辣椒油和甲醛溶液等方法评价。结果表明：分散助剂自身的酸碱属性及分子结构对纳米TiO₂分散体系有重要影响,其中PAAS分散效果最佳;纳米TiO₂在PFN-NWF上包覆均匀,负载率为4.79%,负载牢度高;自然光照射60 min,试样上2 mL油污达到完全自清洁效果;300 W氙灯照射2 h,TiO₂/PFN-NWF光催化复合材料试样对甲醛的降解率达到95.98%,5次循环使用后,降解率为90.19%。     

表面活性剂辅助农药在锂皂石中的插层及其性能

利用两性表面活性剂十六烷基磺基甜菜碱(SB)的辅助作用实现了农药功夫菊酯(LCT)在锂皂石(LAP)中的插层。先用离子交换法将SB、十二烷基羧基甜菜碱(DCB)、十二烷基氧化胺(OA)和阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)分别插层LAP,然后用SB胶束将LCT引入层间,得到LCT/SB-LAP、LCT/DCB-SB-LAP、LCT/OA-SB-LAP和LCT/CTAB-SB-LAP复合材料。采用X射线衍射(XRD)、液体核磁共振(¹HNMR)、电感耦合等离子发射光谱(ICP-OES)、傅里叶变换红外光谱(FT-IR)、热重/差热分析(TGA/DTA)和扫描电镜(SEM)对复合材料进行了表征。结果表明,LCT/SB-LAP、LCT/DCB-SB-LAP、LCT/OA-SB-LAP和LCT/CTAB-SB-LAP的层间高度分别为3.61、3.13、3.13和3.41 nm;LCT伴随SB分子成功进入LAP层间。提出了LCT在LAP中的插层机理。对复合材料中LCT释放行为的研究结果表明,释放速率和累积释放量主要依赖表面活性剂类型及其在层间的排列方式。     

碳纤维负载NaTaO3光催化复合材料的制备及其性能碳纤维负载NaTaO3光催化复合材料的制备及其性能

以聚丙烯腈基碳纤维（CF）为基体,TaCl₅和乙酸钠为原料,十六烷基三甲基溴化铵（CTAB）为表面活性剂,通过溶胶-凝胶法和浸渍提拉法将纳米NaTaO₃薄膜负载于CF上,制备得到高效光催化特性的复合材料。采用SEM、TEM、XRD等表征了NaTaO₃-CF的形貌和结构,以罗丹明B （RhB）溶液为目标降解物,测试了NaTaO₃-CF复合材料的光催化性能。结果表明:所制备的NaTaO₃-CF复合材料具备良好光催化活性和重复使用稳定性,暗中吸附30 min、光照80 min时,对RhB的去除率为99.35%,5次循环使用后,去除率为89.17%,其光催化反应过程符合伪一级反应动力学模型。      

Synthesis of polyaniline nanostructures in different lamellar liquid crystals and application to lubrication

Polyaniline (PANI) nanostructures were synthesized in lamellar liquid crystal (LLC) formed by different surfactants. It was found that PANI presented lamellar nanostructures by using the template of LLC formed by ionic surfactant of sodium dodecyl sulfonate (SDS) or hexadecyltrimethylammonium bromide (CTAB), whereas PANI spheric nanostructures were obtained within the LLC template formed by the nonionic surfactant of Triton X-100. The formation mechanisms of PANI nanostructures were discussed. Besides, the lubricating effect of PANI in LLC template was also investigated, and the results showed that spheric PANI had better lubricative performance than lamellar PANI.     

Modulation of the wettability of excipients by surfactant and its impacts on the disintegration and release of tablets

Objective: To investigate the modulation of the wettability of excipients by different types of surfactants and its impacts on the disintegration of tablets and drug release.

Materials and methods: The critical micelle concentration (CMC) of surfactants, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), dodecyl trimethyl ammonium bromide (DTAB), cetyltrimethyl ammonium bromide (CTAB) and polysorbate (Tween-20 and Tween-80), was obtained using the platinum ring method. Contact angles of surfactant solutions on the excipient compacts and double-distilled water on the mixture of surfactant and the other excipient (magnesium stearate (MgSt) or sodium alginate (SA)) were measured by the sessile drop technique. Besides, surface free energy of excipients was calculated by the Owens method. Finally, the disintegration of tablets and in vitro dissolution testing were performed according to the method described in USP.

Results and discussion: The wettability of excipients could be enhanced to different extent with low concentration of surfactant solutions and maintained stable basically after CMC. For MgSt (hydrophobic excipient), the shorter the hydrophobic chain (C₁₂, including SDS and DTAB), the better the wettability with the addition of surfactant in the formulation, leading to the shorter disintegration time of tablets and higher drug release rate. In contrast, the wettability of SA (hydrophilic excipient) was reduced by adding surfactant, resulting in the longer disintegration time of tablets and lower release rate.

Conclusion: The modulation of the wetting of pharmaceutical excipients by surfactant had changed the disintegration time of tablets and drug release rate to a greater extent.     

Surfactant-assisted synthesis of reduced graphene oxide/polyaniline composites by gamma irradiation for supercapacitors

A series of graphene materials are prepared by intercalation of graphene oxide (GO) with different surfactants, cetyltrimethylammonium bromide (CTAB), n-octyltrimethylammonium bromide, tetramethylammonium bromide, and sodium dodecylbenzene sulfonate, subsequently by γ-ray induced reduction in N-methyl-2-pyrrolidone (NMP) at room temperature. GO can be reduced by the electrons generated from the radiolysis of NMP under γ-ray irradiation, and reduced GO is simultaneously functionalized by the radiolytic product of NMP. Cationic surfactant CTAB with longer alkyl chains can effectively promote the reduction process of GO by preventing the aggregation of graphene sheets, which has been testified by X-ray photoelectron spectroscopy, X-ray diffraction, thermogravimetric analysis, Raman spectroscopy, and Fourier transform infrared spectroscopy analyses. Furthermore, when the as-prepared graphene/polyaniline composites are used for supercapacitor electrode materials, there is a highest specific capacitance of 484 F g^?1 at a current density of 0.1 A g^?1 for the graphene produced in the presence of cationic surfactant CTAB.     

CTAB辅助水热合成球状纳米花MoS2/C复合材料及其电化学性能研究

以钼酸钠(Na₂MoO₄·2H₂O)、硫脲(NH₂CSNH₂)、CTAB为原料, 利用水热法合成了MoS₂/C球状纳米花复合材料。通过XRD、SEM、TEM、TG等分析测试方法, 研究了不同CTAB添加量对MoS₂/C复合材料的微观结构、表面形貌的影响规律, 结果显示, 有部分无定形碳嵌入了MoS₂层间, 并抑制了MoS₂(002)面的堆积。电化学测试表明: 与纯MoS₂相比, MoS₂/C复合材料具有更好的电化学性能, 当加入0.025 g CTAB时首次放电比容量达到730 mAh/g, 在100 mA/g的电流密度下经过100次循环比容量稳定在415 mAh/g。在此基础上讨论了MoS₂/C球状纳米花复合材料的可能生长机理以及对材料电化学性能的影响规律。     

Treating chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation process with surfactant

The effect of surfactants on the treatment of chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation (ECF) process was studied. Two surfactants, cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) were employed in this study to compare the effect of cationic (CTAB) and anodic (SDS) surfactants on ECF. The cationic surfactant can enhance the removal of the turbidity, but anodic surfactant cannot. It can be explained by the hetero-coagulation theory. Moreover, the addition of CTAB in CMP wastewater can reduce the sludge volume and the flotation/sedimentation time in ECF process. The residual turbidity and dissolved silicon dropped with the increase of charge loading. No CTAB pollution problem exists after the ECF process.     

表面活性剂对镁合金化学复合镀Ni-P-SiC的影响

本工作系统地考察了十二烷基苯磺酸钠(ABS-Na)、十二烷基硫酸钠(DS)、聚乙二醇(6000)(PEG(6000))、吐温-80(Tween-80)等表面活性剂及其组合对镁合金化学复合镀Ni-P-SiC的镀液稳定性、镀速、镀层表面形貌和性能的影响,并优选了适合镁合金化学复合镀Ni-P-SiC镀层的表面活性剂。结果表明:随着表面活性剂加入,镀液稳定性明显改善;表面活性剂的种类对镀速有重要影响,含十二烷基苯磺酸钠+聚乙二醇(6000)复合型表面活性剂的镀液镀速最快。综合考虑复合镀层的表面质量、显微硬度和耐腐蚀性能,优选的适于镁合金化学复合镀Ni-P-SiC的表面活性剂是十二烷基硫酸钠+聚乙二醇(6000)的复合物。     

Surfactant-mediated growth of nanostructured zinc oxide thin films via electrodeposition and their photoelectrochemical performance

Zinc oxide (ZnO) thin films were electrodeposited from an aqueous zinc acetate solution onto fluorine-doped thin oxide (FTO) coated conducting glass substrates. The effect of organic surfactants like polyvinyl pyrrolidone (PVP), sodium dodecyl sulfate (SDS), polyethylene glycol (PEG), ethylene glycol (EG) and polyvinyl alcohol (PVA) on their structural, morphological, optical and photoelectrochemical properties was studied. The x-ray diffraction patterns revealed the formation of phase-pure ZnO thin films. The films deposited using organic surfactants exhibit different surface morphologies. It was observed that the organic surfactants play important roles in modifying the surface morphology and size of the crystallites. A compact granular morphology was observed for the ZnO samples grown without organic surfactants. The films exhibit nanoparticles of size 100-150?nm for PVP, EG and PVA mediated growth. The vertically aligned thin and compact hexagonal crystallites stem from the SDS, whereas microporous corrugated morphology is observed for PEG-mediated growth. All the samples exhibit room temperature photoluminescence (PL). Oxygen vacancies contribute to the active luminescent centers for the emission of green light in ZnO thin films. PL gets quenched for the SDS surfactant. All the samples were post-treated with ethanol to remove stray surfactant molecules. FTIR study was used to confirm the removal of adsorbed surfactant molecules from the samples. Moreover the samples are photoelectrochemically (PEC) active and exhibit the highest photocurrent of 231?μA, a photovoltage of 492?mV and 0.42 fill factor for the ZnO:SDS films.     

Synthesis and characterization of monodisperse hematite nanoparticles modified by surfactants via hydrothermal approach

Monodisperse rhombohedral α-Fe₂O₃ nanoparticles modified by four different surfactants, sodium dodecylsulfonate (SDS), sodium dodecylebenzene sulphonate (DBS), cetyltrimethyl ammonium bromide (CTAB) and hexadecyipyridinium chloride (HPC), have been synthesized via hydrothermal method, using FeC₂O₄ and NaOH as starting precursors. Meanwhile, monodisperse rodlike α-Fe₂O₃ nanoparticles without surfactant are also prepared under the same conditions for comparison. The products were characterized by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron micrograph (TEM) and magnetization measurements. The products with and without surfactant all exhibit weak ferromagnetic properties at room temperature, except somewhat variation in coercivity values. The experimental results suggest that the surfactants can significantly influence the size and shape of the particles, but cannot affect their magnetic nature.