改性沸石/TiO2的制备及光催化降解亚甲基蓝

使用碱液侵蚀加煅烧的方法对天然沸石改性,获得改性沸石.以改性沸石为载体,钛酸丁酯为前驱体,使用溶胶-凝胶法制备了改性沸石/TiO2催化剂.使用亚甲基蓝作为目标污染物,测试改性沸石/TiO2催化剂的降解性能.结果表明,采用改性沸石负载TiO2的方法有助于提高光催化剂的利用效率,当TiO2的负载率为6.08;时,对亚甲基蓝的降解效率高达0.935.XRD、SEM-EDS、BET、FTIR测试结果表明,TiO2以纳米尺度在改性沸石表面均匀分布,并且与改性沸石建立了较强的化学键连接,有利于改性沸石/TiO2催化剂的长期性能.     

磁性Fe3O4/膨胀石墨对亚甲基蓝的吸附性能研究

以膨胀石墨(EG)为载体,采用简单的水热法,制备出磁性Fe3O4/膨胀石墨(MEG).采用X-射线衍射仪(XRD)和扫描电子显微镜(SEM)对MEG的组成结构和形貌进行表征.以亚甲基蓝为目标污染物,探讨了溶液pH值、吸附时间、盐离子浓度和亚甲基蓝初始浓度对吸附性能的影响,并对吸附动力学和吸附等温线进行研究.结果表明:当亚甲基蓝初始浓度为50 mg·L-1,pH值为7,吸附时间为60 min时,对亚甲基蓝的去除率和吸附量分别为97.03;和48.52 mg·g-1,随着溶液中盐离子Na+和Ca2浓度的增加,MEG对亚甲基蓝的吸附性能降低;MEG对亚甲基蓝的吸附行为符合拟二级动力学模型和Langmuir等温吸附模型.MEG可以使用磁铁进行分离回收,回收率达95.71;.5次吸附-再生后,吸附量仍较高为41.72 mg·g-1,说明MEG吸附剂具有较稳定的重复使用能力.     

利用不同硅前体制备超疏水性白炭黑膜

以稻壳灰和水玻璃为前驱体,以氨基硅油(amino silicon oil-ASO)为改性剂,采用溶胶-凝胶法制备不同性能的超疏水性白炭黑及其膜.主要研究不同前驱体和改性剂用量对白炭黑疏水性膜性能的影响,通过扫描电子显微镜、傅里叶变换红外光谱仪和润湿接触角进行性能表征.研究结果表明,以稻壳灰或水玻璃为前驱体,采用改进的溶胶-凝胶法均能制备出接触角大于160°的SiO2超疏水膜;采用相同的改性剂,可以得到颗粒形态完全不同的SiO2膜;改性剂的作用对SiO2表面改性作用是一种接枝反应,将疏水性基团接枝替代SiO2表面的羟基,而使SiO2表面疏水,且能起到模板作用,引导水玻璃溶胶颗粒聚合成棒状或纤维状结构.     

表面活性剂改性碳气凝胶吸附亚甲基蓝性能的研究

以间苯二酚和甲醛为碳前体,分别以十二烷基苯磺酸钠、十二烷基硫酸钠、十六烷基三甲基溴化铵为模板剂,采用溶胶凝胶法制备碳气凝胶材料.采用TG、XRD、SEM、N2吸脱附法等技术手段对其结构、形貌及热稳定性进行表征,探讨了吸附时间、染料初始浓度等因素对亚甲基蓝吸附性能的影响.结果表明,表面活性剂改性后的碳气凝胶孔结构较原生的碳气凝胶丰富;以十二烷基苯磺酸钠作模板剂所制得的样品吸附性能最佳,吸附条件为:样品用量为25 mg、染料浓度为300 mg/mL、吸附时间为5 h.对吸附机理研究表明,吸附剂去除亚甲基蓝符合Langmuir吸附模型,吸附动力学研究表明吸附行为符合二级动力学模型.     

乙烯基三甲氧基硅烷对二氧化硅的超疏水改性研究

采用乙烯基三甲氧基硅烷(VTMO)为改性剂,以氨水为pH调节剂制备改性二氧化硅(SiO2)超疏水材料.通过CA、FTIR和SEM对材料接触角、组成和形貌进行表征.考察了VTMO与SiO2的比例、反应时间、干燥时间对改性二氧化硅超疏水材料接触角和形貌的影响.结果表明,VTMO可在较短时间内改性二氧化硅制备出超疏水二氧化硅粉体,VTMO与SiO2比例对改性SiO2粉体的水接触角和微观二重结构有明显影响,而反应时间和干燥时间的影响较小.     

MCM-41固载牛血清白蛋白复合材料的制备、表征及发光

本研究首先利用水热法制备出了纳米分子筛MCM-41,然后把牛血清白蛋白(Bovine serum albumin,BSA)物理吸附法固载在主体MCM-41中,制备出(MCM-41)-BSA复合材料.化学分析表明,BSA已进入上述主体材料中,固载量为55.68 mg (BSA)/g(MCM-41).粉末X射线衍射(XRD)结果表明,复合材料的结晶度保持良好,分子筛的基本骨架保存完好没有由于BSA的引入而遭到破坏.77 K低温N2吸附-解吸附的研究结果说明,BSA部分进入了分子筛孔道中.扫描电镜(SEM)测量结果显示,(MCM-41)-BSA样品的直径为100±10 nm.发光研究表明,(MCM-41)-BSA样品中BSA的构象未发生变化.     

以稻壳灰为硅源制备超疏水性白炭黑

以稻壳为原料,采用自蔓延燃烧法制备高活性的稻壳灰.以稻壳灰为原料,采用碱溶煮-酸反应法制备较高纯度的白炭黑.以六甲基二硅氮烷(HMS)为改性剂,采用溶胶-凝胶法制备超疏水性的白炭黑及其膜.主要研究酸反应过程中的pH值和反应时间对白炭黑中SiO2含量的影响,以及六甲基二硅氮烷改性剂对白炭黑(SiO2)膜疏水性能的影响,通过XRD、SEM、IR和润湿接触角进行性能表征.研究结果表明,将稻壳灰在NaOH溶液中加热到90℃后溶煮2h,再用硫酸调节溶液的pH值为3,反应时间控制在2h时,白炭黑SiO2的含量可达98.48;.当六甲基二硅氮烷用.量为0.15(与硅钠溶液的质量之比)时,可以获得接触角为166.3.的SiO2的SiO2超疏水膜.而改性剂对SiO2表面改性作用是一种接枝反应,将疏水性基团接枝替代SiO2表面的羟基,而使SiO2表面疏水.     

Ag修饰纳米氧化锌的制备及光催化活性分析

以二水合醋酸锌和一缩二乙二醇为原料,在非水体系中超声辅助获得纳米氧化锌光催化剂.采用亚甲基蓝水溶液为模拟研究对象,结合羟基自由基(·OH)清除剂叔丁醇、超氧自由基抑制剂(O·-2)对苯醌以及光催化助剂H2 O2,分析了纳米氧化锌光催化降解亚甲基蓝体系中活性氧物种主要有·OH和O·-2.同时,对氧化锌进行了银修饰研究,结果表明:金属Ag单质均匀分散于ZnO基底表面,修饰后的样品光响应范围拓宽至可见光区,Ag修饰提高了光生空穴和电子的分离效率,改善了催化剂的光催化性能.     

利用稻壳制备X型分子筛及性能研究

以稻壳为硅源,采用水热法成功合成出了X型分子筛,并对亚甲基蓝染料进行吸附.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见光谱和钙离子交换能力对样品的性能进行表征与测试.研究结果表明,提纯后稻壳灰为无定型态,其主要成分SiO2含量高达98.96;;水热法合成X分子筛的最佳配比为n(SiO2)/n(Al2O3) =3.8、n(Na2O)/n(SiO2)=1.4、n(H2O)/n(Na2O) =40,最佳水热晶化温度为100℃,最佳晶化时间为8h.在此条件下,合成产物无杂相,晶形发育完好,结晶度高,钙离子交换能力高达310.3 mg·g-1.亚甲基蓝溶液初始pH值在11 ～12范围内,初始浓度小于30 mg·L-1,分子筛用量在0.10～0.25 g范围内时,产物对亚甲基蓝有较好的吸附效果.     

四方体MgO的制备及对有机染料的吸附

以六水氯化镁和六次甲基四胺为原料,采用水热法合成四方体MgO,考察其对有机染料甲基橙和亚甲基蓝的吸附行为.通过TGA-DTA、SEM、XRD、N2-sorption和FT-IR等手段表征样品.结果表明,原料浓度、温度和表面活性剂对四方体MgO结构的形成影响较小,而反应时间的延长有助于有序结构的组装.温度170℃、时间24h、MgCl2·6H2O与C6H12N4浓度比为1∶2和表面活性剂PVP是制备四方体MgO的最佳条件.在溶液浓度10mg · L-1的单一吸附实验过程中,四方体MgO对甲基橙和亚甲基蓝的去除率分别为91.3;和22.3;,吸附过程均为单层吸附且符合Langmuir等温吸附模型和伪二级吸附动力学方程.在溶液浓度40 mg·L-1、甲基橙和亚甲基蓝浓度比3∶1的混合溶液吸附过程中,四方体MgO对甲基橙和亚甲基蓝的去除率分别为80.1;和97.9;.     

First-principles coexistence simulations of supercooled liquid silicon

We perform first-principles coexistence simulations of the low-density and the high-density phases of supercooled liquid silicon and find a negative slope for the coexisting line in the temperature-pressure plane. Electron density maps and electron-localization function plots of the two phases of silicon show marked differences. The calculated differences suggest more localized electrons in the low-density liquid compared to the high-density liquid, coming from an increased population of covalent bonds, which further explain the calculated negative slope in the two phase coexistence regime. This is consistent with the presence of a pseudo-gap in low-density liquid silicon, absent in the high-density liquid which shows a metallic behavior.     

Triethyl ammonium salt of O,O′-bis(p-tolyl)dithiophosphate, [Et3NH]+[(4-MeC6H4O)2PS2]−

Triethyl ammonium Salt of O,O′-bis(p-tolyl)dithiophosphate and O,O′-bis(m-tolyl)dithiophosphate have been obtained by reaction of p- and m-cresol, respectively with P₂S₅ in toluene and have been characterized by elemental analysis, IR, ¹H and ³¹P NMR spectroscopy. The molecular structure of O,O′-bis(p-tolyl)dithiophosphate has been determined. Crystal data: [Et₃NH]⁺[(4-MeC₆H₄O)₂PS₂]⁻: Monoclinic, P2₁/c, a=15.2441(9) ?, b=10.415(2) ?, c=3.9726(9) ?, β=91.709(7)°, V=2217.5(1) ?⁻³, Z=4.Supplementary materials Additional material available from the Cambridge Crystallographic Data Centre (CCDC no. 600927 for [Et₃NH]⁺[(4-MeC₆H₄O)₂PS₂]⁻ comprises the final atomic coordinates for all atoms, thermal parameters, and a complete listing of bond distances and angles. Copies of this information may be obtained free of charge on application to The Director, 12 Union Road, Cambridge CB2 2EZ, UK (fax: +44-1223-336033; email: deposit@ccdc.cam.ac.uk or www:http://www.ccdc.cam.ac.uk).     

Crystal structures of thecis andtrans isomers of dithiahexahydro[3.3]metacyclophane

Structures of both thecis andtrans isomers of dithiahexahydro[3.3]metacyclophane, ?C₆H₄?CH₂SCH₂?C₆H₁₀?CH₂SCH₂?, have been determined, wherecis andtrans refer to the attachments to the cyclohexane ring. Thecis form crystallizes in the monoclinic space groupP2₁/c witha=8.4299(11)Å,b=21.772(2)Å,c=8.9724(13)Å, β=116.574(11)^o, andZ=4. Thetrans isomer packs into the monoclinic space groupP2₁ witha=8.159(16)Å,b=10.185(5)Å,c=9.558(2)Å, β=112.435(18)^o, andZ=2. The cyclohexane ring of thecis isomer is in the chair conformation, while the cyclohexane of thetrans isomer is found in a twisted boat conformation.     

CTAB与SDBS对碳酸锶粒子生长形态调控及机理研究

以表面活性剂CTAB和SDBS为化学添加剂,采用化学共沉淀法对碳酸锶晶体的生长形态进行调控,成功地制备出了实心的树枝状和花瓣为空心的花状碳酸锶粉体,并用X射线衍射(XRD)、扫描电子显微镜(SEM)和傅里叶变换红外光谱(FT-IR)等分析手段对样品进行了表征;最后重点对化学添加剂可能产生的影响机理进行了初步的探讨.结果表明,CTAB和SDBS在晶体生长的过程中能起到显著的影响作用,两者对粒子分散性能的作用效果相反,而且后者对晶体(013)和(213)晶面表面能降低的贡献明显大于前者.     

Crystal structures of the cis and trans isomers of a tetrathia[3.3.3.3]cyclophane

Both the cis and trans isomers of 3,11,18,26-tetrathiatricyclo[26.2.2.1^5,9.2^13,16.1^20,24] hexatriaconta-5,7,9,20,22,24-hexene have been prepared and structurally characterized. Each of these centrosymmetric tetrathia dimers includes two cyclohexane rings in chair conformations with either 1,4-cis or 1,4-trans bonding and two meta-substituted benzene rings. The cis isomer packs into the monoclinic space group P2₁/a with a = 10.485(3)Å, b = 10.3956(18)Å, c = 14.1343(10)Å, = 105.200(13)°, Z = 2 and refined to an R factor of 0.046. The trans isomer crystallizes in the monoclinic space group P2₁/c with a = 10.7217(12)Å, b = 5.6797(7)Å, c = 25.415(5)Å, = 96.001(12)°, Z = 2 and refined to an R factor of 0.043. In the cis structure each benzene ring faces a cyclohexane ring while in the trans structure the cyclohexane rings face one another.     

Crystal structure of Zn4Na(OH)6SO4Cl·6H2O

The structure of Zn₄Na(OH)₆SO₄Cl·6H₂O, a secondary mineral from Hettstedt, Germany, was determined by single-crystal X-ray diffraction. The crystals are hexagonal,a=8.413(8),c=13.095(24) Å, space group $P\bar 3$ , Z=2. The structure was refined to R=0.0554 and R_w=0.0903 for 970 reflections with I≥3σ(I). The structure can be described as zinc hydroxide layers perpendicular toc, from which sulfates and chlorides extend. The layers are held together by a system of hydrogen bonds involving hexaaquo Na⁺ ions which occupy the interlayer space.     

Synthesis and Crystal Structure of 5-[2-(6-bromonaphthalenyloxymethyl)]-3-(4-morpholinomethyl)-1,3,4-oxadiazole-2(3<Emphasis Type="Italic">H</Emphasis>)-thione

Abstract  The title compound, C₁₈H₁₈BrN₃O₃S, a derivative of 1,3,4-oxadiazole, crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.8731(3), b = 8.9994(4), c = 15.7099(6) ?, α = 92.779(3)°, β = 130.575(3)°, γ = 107.868(4)°, Z = 2. The dihedral angle between the mean planes of the planar naphthyl and morpholine (chair) rings with the planar oxadiazol ring is 50.1(8) and 76.8(6)°, respectively. The planar naphthyl ring is twisted 52.2(5)° with the mean plane of the morpholine ring. A group of four intermolecular close contacts are observed between a bromine atom and hydrogen atoms from the closely packed naphthyl, morpholine and oxy–methyl groups in the unit cell. These molecular interactions in concert with an additional series of π–π stacking interactions that occur between the center of gravity of the two 6-membered rings of the naphthalene group influence the twist angles of each of these three groups. A MOPAC AM1 calculation of the conformation energy of the crystal structure [226.0128(9) kcal] compared to that of the minimum energy structure after geometry optimization [29.9744(1) kcal] reveals a significantly reduced value. The twist angles of the three groups above also change after the AM1 calculation giving support to the influence of both intermolecular C–H···Br short-range interactions and Cg π–π stacking interactions on these angles which therefore play a role in stabilizing crystal packing. Graphical Abstract  Crystal structure of 5-{[(6-bromonaphthalen-2-yl)oxy]methyl}-3-(morpholin-4-ylmethyl)-1,3,4-oxadiazole-2(3H)-thione, C₁₈H₁₈BrN₃O₃S, is reported and its geometric and packing parameters described and compared to a MOPAC computational calculation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

电沉积法制备ZnO纳米棒阵列及其发光特性

本文以掺F的SnO2导电玻璃为基板,以硝酸锌水溶液为电解液,采用三电极恒电位体系电沉积制备ZnO纳米棒阵列,系统考察了硝酸锌浓度和沉积电位等工艺参数对ZnO纳米棒阵列的微观形貌及其发光性能的影响规律.结果表明,硝酸锌浓度和沉积电位对纳米棒阵列的形貌有显著影响,控制适宜的工艺条件可以制备出直径分布均匀、结晶性好且纯度高的六方纤锌矿ZnO纳米棒阵列.荧光光谱分析表明,电沉积制备出的ZnO纳米棒阵列在385 nm附近有一个强荧光发射峰,且发光性能稳定、对纳米棒阵列微观形貌的细微变化不敏感,使其在发光二极管和激光器等领域具有广阔的应用前景.     

Crystal structure of irisolidone from the flowers of Pueraia lobata

Irisolidone (5,7-dihydroxy-6,4′-dimethoxyisoflavone) was isolated from the flowers of Pueraia lobata and its crystal structure was examined by X-ray single crystal diffraction. The crystal structure of irisolidone is monoclinic, space group P2₁/c with a = 15.491(9) ?, b = 7.895(4) ?, c = 13.321(7) ?, β = 110.546(9)° and Z = 4. Hydrogen bonding and aromatic π–π stacking assemble the title compound into a three-dimensional networking structure.