凹凸棒石/羧甲基纤维素钠复合材料的制备及其吸附性能

以凹凸棒石(Attapulgite,AT)和羧甲基纤维素钠(Sodium carboxymethyl cellulose,CMC-Na)为原料,采用溶液共混法制备了凹凸棒石/羧甲基纤维素钠复合材料.探讨了凹凸棒石和羧甲基纤维素钠质量比对复合材料吸附盐酸四环素的影响,结果表明,当凹凸棒石与羧甲基纤维素钠质量比为3∶20时,复合材料的吸附性能最佳,吸附量为132.59 mg/g.并利用傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、热重分析(TG)、扫描电子显微镜(SEM)和比表面积仪对复合材料进行了表征.考察了吸附时间、吸附温度和溶液pH值对复合材料吸附盐酸四环素的影响,研究了其吸附过程.结果 表明,当吸附温度为30℃、吸附时间为1.0h、pH值为3时,吸附能力较大,为157.55 mg/g,复合材料对盐酸四环素的吸附过程符合Langmuir吸附等温式和准二级动力学模型.     

改性黄腐酸/凹凸棒石复合材料的制备及其抑菌性能

黄腐酸(FA)具有抑菌消炎和促进动物生长的功效.为了进一步提升FA的广谱抑菌性,以凹凸棒石(APT)为载体,通过吸附法将FA负载于APT,同时进行十六烷基三甲基溴化铵(CTAB)改性.结果表明,FA和APT主要以静电吸附形式结合,CTAB的引入实现了FA/APT复合材料的电荷调控.复合材料对大肠杆菌和金黄色葡萄球菌的最...     

CuO/腐植酸复合材料的制备及其吸附性能

采用水热法合成了CuO-腐植酸（HA）纳米复合材料,研究了其对亚甲基蓝的初始吸附性能及再生吸附性能。运用扫描电镜/能谱仪（SEM/EDS）、傅里叶变换红外光谱仪（FTIR）、X射线粉末衍射仪（XRD）、激光粒度分析仪和比表面积测定仪（BET）对其结构进行了表征。研究了pH、亚甲基蓝初始浓度和反应温度等因素对CuO/HA吸附亚甲基蓝的影响,采用多种模型研究了CuO/HA复合材料对亚甲基蓝的吸附动力学和热力学行为。结果表明：合成的CuO/HA平均粒径约为135.0nm,比表面积为188.15m²/g。CuO/HA对亚甲基蓝（MB）的吸附动力学行为符合拟一级动力学模型,在60min内达到吸附平衡,较好地符合Frendlich吸附模型。在室温下pH=7时,CuO/HA复合材料初始饱和吸附量达172.01mg/g;循环使用8次,可保持初始吸附能力的89.27%,表明有较好的吸附性能,可作为一种有效除去水体中亚甲基蓝污染物的高容量吸附材料。     

凹凸棒-TiO_2复合材料的制备及其吸附性能的研究

文章选择凹凸棒土作为TiO2的载体,采用溶胶--凝胶法制备凹凸棒-TiO2复合材料光催化剂,以亚甲基蓝为底物进行有机物降解实验,探讨染料废水处理的新途径。结果表明随着凹凸棒粘土目数的增大复合材料对苯酚的吸附能力亦增大;复合材料中凹凸棒粘土所占比例增大,其吸附能力先增大后减小;采用超声条件反应复合材料的吸附性能有所下降。     

凹凸棒石黏土的提纯及其吸附性能的研究

考察了凹凸棒石黏土原矿的粒径、液固比、分散剂种类及用量对江苏盱眙凹凸棒石提纯土吸附性能的影响,并进行了激光粒度检测、X射线衍射及扫描电镜等分析。结果表明,对醇类发酵废水吸附效果最佳的凹凸棒石黏土提纯条件为:常温常压下,纯水和凹凸棒石黏土的液固比为9 m L/g,分散剂为六偏磷酸钠,用量为凹凸棒石黏土质量的4%,凹凸棒石黏土的粒度为100目。提纯过程可以有效的去除白云石和石英等杂质,提高凹凸棒石黏土的纯度;在分散剂的分散作用下,可以减小凹凸棒石黏土的粒径,使其棒晶变细变短;提纯后的凹凸棒石黏土对醇类发酵废水的吸附性能得到了明显的提高。     

凹凸棒石/Ce1–xZrxO2纳米复合材料的制备及其催化氧化性能

采用共沉淀法制备出凹凸棒石/Ce1–xZrxO2纳米复合材料。通过X射线衍射和透射电子显微镜对复合材料的微观结构与形貌进行表征。考查了不同Zr4＋掺杂量对复合材料结构的影响。结果表明：Zr4＋的掺杂未使CeO2的萤石结构发生变化,活性组分以固溶态负载于凹凸棒表面。当x=0.2,苯酚溶液pH=5.73时,该复合材料对苯酚...     

改性凹凸棒石黏土纳米纤维吸附溶液中痕量Hg~(2+)

在HCl的体系中,采用原位聚合法将聚苯胺接枝到凹凸棒黏土得到改性的凹凸棒石黏土(PANI/ATP)。用傅里叶红外光谱和扫描电子显微镜对PANI/ATP的化学结构和形貌特征进行了表征。研究了PANI/ATP对含痕量Hg2+的模拟废水的吸附性能,并考查了影响Hg2+吸附性能的主要因素,以及吸附过程符合的吸附热力学模型。结果表明,当苯胺和凹土的物料配比为m(An):m(ATP)=1:1时得到的PANI/ATP吸附性能较好;吸附实验中,吸附剂用量为0.2 g,吸附时间120 min时,对汞离子的吸附率达到89.73%;对Hg2+的吸附热力学数据拟合结果符合Langmuir吸附等温方程。     

聚丙烯酸/聚丙烯酰胺/凹凸棒复合材料对亚甲基蓝的吸附性能

将聚(丙烯酸-co-丙烯酰胺)/凹凸棒复合吸附剂用于亚甲蓝的吸附,研究了时间、浓度、酸度、表面活性剂和离子强度等因素对吸附性能的影响。复合吸附剂对亚甲蓝的吸附是吸热过程,60℃时吸附量达到1 273.3 mg.g-1,吸附过程符合Langmuir单分子层吸附等温模式,并计算了热力学常数ΔG、ΔH和ΔS。在实验考察范围内吸附过程均符合准二级动力学特征。该复合吸附剂具有高吸附容量和较快的吸附速率,是良好的亚甲蓝吸附剂。     

凹凸棒石/PES复合膜吸附材料的制备及其吸附Pb2+性能研究

以凹凸棒石和PES(聚醚砜)为原料,采用共混法制备了凹凸棒石/PES复合膜吸附材料,用以吸附溶液中的pb2+.用傅立叶红外光谱和扫描电子显微镜对复合膜的结构进行表征,并测试了复合膜的机械性能.考察了吸附时间、溶液初始浓度和pH对吸附效果的影响,并探讨了吸附过程的热力学和动力学.结果表明:凹凸棒石含量为21％时综合性能最佳.25℃条件下,对pb2+的吸附5h达到平衡,最大吸附量为65.06 mg/g,弱酸性和中性条件下吸附效果较佳,吸附过程符合Langmuir吸附等温式和伪二级动力学模型.复合膜可以用盐酸洗脱再生,三次再生产物对Pb2+仍具有较高的吸附量.     

凹凸棒土/石墨复合材料电极的制备及性质

以酸化处理的凹凸棒土粉和膨胀处理的石墨粉为原料、环氧树脂为粘合剂,制得凹凸棒土/石墨复合材料电极。采用扫描电镜、红外光谱等对其形貌和结构进行表征。探讨了电极材料类型、富集时间、平行测定次数对模拟苯酚废水峰电流的影响。研究结果表明,凹凸棒土/石墨复合材料电极比普通石墨电极对峰电流的响应更明显,且稳定性好,无二次污染。     

纳米二氧化硅/凹土复合材料的制备以及吸附性能

以硅酸钠为主要原料,用硫酸调节pH,通过液相沉淀法在凹土单晶表面原位生成纳米粒状二氧化硅,制备纳米二氧化硅/凹土复合粉体。利用XRD、TEM、TG-DTG、氮气吸附脱附曲线等方法对复合粉体进行表征。XRD表明,二氧化硅以非晶态的形式包覆在凹土表面,防止了凹土的团聚。TEM照片显示,包覆后的纳米二氧化硅粒径减小,粒度分布均匀,表面光滑。     

Synthesis and characterization of polysaccharide-maghemite composite nanoparticles and their antibacterial properties

The aim of this study was to obtain saccharide (dextran and sucrose)-coated maghemite nanoparticles with antibacterial activity. The polysaccharide-coated maghemite nanoparticles were synthesized by an adapted coprecipitation method. X-ray diffraction (XRD) studies demonstrate that the obtained polysaccharide-coated maghemite nanoparticles can be indexed into the spinel cubic lattice with a lattice parameter of 8.35 Å. The refinement of XRD spectra indicated that no other phases except the maghemite are detectable. The characterization of the polysaccharide-coated maghemite nanoparticles by various techniques is described. The antibacterial activity of these polysaccharide-coated maghemite nanoparticles (NPs) was tested against Pseudomonas aeruginosa 1397, Enterococcus faecalis ATCC 29212, Candida krusei 963, and Escherichia coli ATCC 25922 and was found to be dependent on the polysaccharide type. The antibacterial activity of dextran-coated maghemite was significantly higher than that of sucrose-coated maghemite. The antibacterial studies showed the potential of dextran-coated iron oxide NPs to be used in a wide range of medical infections.     

Synthesis of CuO/MXene nanocomposite to study its photocatalytic and antibacterial properties

In this work, bare copper oxide CuO nanoparticles, MXene nanosheets and their CuO/MXene nanocomposite were synthesized for enhanced photocatalytic activity. CuO nanoparticles were prepared hydrothermally, MXene was synthesized via HF etching, and their nanocomposite was formed via a simple ultrasonication route. The as-prepared materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques to analyse their structural and functional group features. Scanning electron microscopy (SEM) analysis was used to evaluate the surface morphologies of all the samples. UV–visible spectroscopic analysis was used to calculate the band gap energies of CuO, MXene and CuO/MXene. The enhanced surface area of the synthesized nanocomposite supported excellent photocatalytic activity. The maximum degradation of methylene blue by CuO/MXene was recorded at approximately 1 h. The higher degradation rate of methylene blue by the nanocomposite is due to the effective intercalation of nanoparticles between the MXene nanosheets, resulting in increased electron trapping ability of the photocatalyst.     

凹凸棒石/CoFe_2O_4磁性复合材料制备及对亚甲基蓝吸附性能

通过低温回流法制备具有吸附和磁性能的凹凸棒石/CoFe2O4磁性复合材料(MAT),利用傅里叶红外光谱(FTIR)、振动样品磁强计(VSM)、扫描电镜(SEM)、X射线衍射(XRD)等对MAT进行表征,并研究了MAT对亚甲基蓝(MB)的吸附性能。结果表明,磁性粒子CoFe2O4以简单的物理沉积负载于凹凸棒石表面;MAT饱和比磁化强度14 emu/g,磁性较强,易于磁分离;比表面积175.85 m2/g,略大于凹凸棒石。对于25 m L浓度100 mg/L MB溶液,MAT最佳投加量为0.050 g;在pH 3⁹范围内,MAT吸附量随pH值的增大而增大;当温度在2939范围内,MAT吸附量随pH值的增大而增大;当温度在293³38 K,MAT的吸附等温线符合Langmuir方程,吸附焓变1.61 k J/mol,Gibbs自由能变-28.51338 K,MAT的吸附等温线符合Langmuir方程,吸附焓变1.61 k J/mol,Gibbs自由能变-28.51³3.16 k J/mol,吸附熵变102.4833.16 k J/mol,吸附熵变102.48¹02.87 k J/mol,表明该吸附是个吸热、自发且熵增过程;MAT对MB的吸附动力学符合准二级动力学方程,是外表面吸附。     

凹凸棒石/CoFe_2O_4磁性复合材料制备及对亚甲基蓝吸附性能

通过低温回流法制备具有吸附和磁性能的凹凸棒石/CoFe2O4磁性复合材料(MAT),利用傅里叶红外光谱(FTIR)、振动样品磁强计(VSM)、扫描电镜(SEM)、X射线衍射(XRD)等对MAT进行表征,并研究了MAT对亚甲基蓝(MB)的吸附性能。结果表明,磁性粒子CoFe2O4以简单的物理沉积负载于凹凸棒石表面;MAT饱和比磁化强度14 emu/g,磁性较强,易于磁分离;比表面积175.85 m2/g,略大于凹凸棒石。对于25 m L浓度100 mg/L MB溶液,MAT最佳投加量为0.050 g;在pH 3~9范围内,MAT吸附量随pH值的增大而增大;当温度在293~338 K,MAT的吸附等温线符合Langmuir方程,吸附焓变1.61 k J/mol,Gibbs自由能变-28.51~33.16 k J/mol,吸附熵变102.48~102.87 k J/mol,表明该吸附是个吸热、自发且熵增过程;MAT对MB的吸附动力学符合准二级动力学方程,是外表面吸附。     

Synthesis and swelling properties of silk sericin-g-poly(acrylic acid/attapulgite) composite superabsorbent

Polymer Bulletin - A composite superabsorbent silk sericin-g-poly(acrylic acid/attapulgite) was synthesized by the aqueous solution copolymerization method with potassium persulfate–sodium...     

改性凹凸棒土的制备及其对SO_2气体的吸附

利用盐酸对凹凸棒土进行改性,改性过程中用正交实验法研究了盐酸改性凹凸棒土的最佳条件,实验证明:盐酸浓度为1 mol/L,盐酸浸泡时间为1 h,热活化温度为250℃时凹凸棒土的改性效果最好。然后将改性好的凹凸棒土制作成复合分子筛,用以吸附SO_2气体,并比较其吸附效果的优劣。实验发现:改性后的凹凸棒土、活性炭、硅烷偶联剂、4A分子筛和氧化铝混合制得的复合分子筛吸附性能最佳。并对凹凸棒土、改性凹凸棒土和复合分子筛的BET、XRD、红外光谱和热重分析进行了测试。结果表明:凹凸棒土的复合分子筛对于吸附SO_2气体具有很好的效果。     

Drawing and ultimate tenacity properties of polyamide 6/attapulgite composite fibers

The drawing and ultimate tenacity properties of the Polyamide 6 (PA6)/Attapulgite (ATP) composite fiber specimens prepared at varying modified ATP (mATP) contents and drawing condition were systematically investigated. As evidenced by Fourier transform infrared (FTIR) and morphological analysis, demarcated translucent resins were found firmly attached on the surfaces of ATP nanofibers. The specific surface areas of the mATP specimens reached a maximum value at 381 m²/g as the weight ratios of silane coupling agents to ATP nanofibers reached an optimum value at 1.0. The percentage crystallinity and melt shear viscosity values measured at varying shear rates of PA6_x(mATP)_y specimens increased consistently as their mATP contents increased. In contrast, melting temperatures of PA6_x(mATP)_y specimens reduced slightly as their mATP contents increased. At a fixed drawing temperature and rate, the achievable draw ratio (D_ra) values of PA6_x(mATP)_y as‐spun fiber specimens approach a maximum value, as their mATP contents are close to the 0.2 wt % optimum value. The maximum D_ra values obtained for PA6_99.8(mATP)_0.2 as‐spun fiber specimens reached another maximum, when their drawing temperatures and rates approached the optimum values at 120°C and 50 mm/min, respectively. At a fixed draw ratio, the tenacity values of PA6_x(mATP)_y drawn fiber specimens drawn at the optimum drawing temperature and rate reached a maximum value, as their mATP contents approached the 0.2 wt % optimum value. Possible reasons accounting for the interesting morphological, specific surface area, drawing, orientation, and ultimate tenacity properties found for the PA6_x(mATP)_y fiber specimens are proposed. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis of Na-doped ZnO nanowires and their antibacterial properties

Na-doped ZnO nanowires with an average diameter of ~ 40 nm have been fabricated by a thermal decomposition route at temperatures around 400 °C. Their properties have been investigated using X-ray diffraction, field emission scanning electron microscope, Raman spectra, photoluminescence spectra and X-ray photoelectron spectra. Photoluminescence spectra showed that the as-synthesized ZnO samples exhibited strong visible emission with a major peak at 420 nm. Furthermore, intensity of the visible emission at 420 nm enhanced as the increase of Na concentration. The improvement of visible emission in the Na-doped ZnO samples should be a result of the surface defects increased by doping of Na in ZnO. Their antibacterial activities were also evaluated by determination of minimum inhibitory concentration (MIC) against Escherichia coli 25922 in vitro. Antibacterial tests indicated these nanomaterials showed good antibacterial properties after UV illumination for a short time.