核壳结构AlOOH的制备、表征及其生长机制

在柠檬酸钠和硝酸铝水溶液体系中, 通过一步水热法制备了蜷缩刺猬状和核壳结构的AlOOH微球, 并用X射线衍射(XRD)、Fourier变换红外(FTIR)光谱、扫描电镜(SEM)、透射电镜(TEM)、氮气吸脱附和光致发光等分析手段对制备的样品进行了形貌和结构表征. 对反应时间、反应物浓度等影响因素进行了研究. 实验结果表明: 反应时间和反应物柠檬酸钠的浓度对所得AlOOH微球结构的尺寸和形貌具有重要影响; 蜷缩刺猬状和核壳结构AlOOH微球都具有较大的比表面积, 分别为171.5和178.6 m2·g-1; 不同形貌的AlOOH具有不同的荧光发射峰. 并初步探讨了核壳结构AlOOH微球的生长机制.     

超声化学法制备SrF2纳米片自组装微球

通过简单的超声化学方法制备了SrF2纳米片自组装微球.合成的产物通过粉末X射线衍射仪、场发射扫描电子显微镜、透射电子显微镜进行了表征和分析.结果表明这些微球是由规则、有序的纳米片组成.而这些纳米片互相垂直连接组装成微球.研究还发现反应物的浓度.配位剂和pH值对产物的形貌和尺寸有着重要的作用.     

回流法可控合成BiPO4纳米棒及其光催化性能

采用回流法合成了BiPO₄纳米棒光催化剂, 探讨了反应时间、反应物比例、pH值和反应物浓度对BiPO₄晶相结构和形貌尺寸的影响, 利用粉末X射线衍射(XRD)、透射电镜(TEM)、比表面积分析(BET)和紫外-可见漫反射光谱(UV-Vis DRS)等对产物进行了表征, 以亚甲基蓝(MB)为探针研究了其光催化活性. 反应时间和反应物浓度对产物的形貌尺寸影响较大, 反应物比例和pH值对产物晶相结构和形貌尺寸均有较大的影响, 进一步影响BiPO₄光催化剂的活性. 调控各种因素后可合成出具有单斜相独居石/六方相混晶结构的高紫外光活性BiPO₄纳米棒光催化剂.     

CuC_2O_4多孔球的可控合成

采用温和水溶液法,以CuCl2.2H2O和H2C2O4.2H2O为原料合成了新颖结构的CuC2O4多孔球。产物结构与形貌用X射线衍射、扫描电子显微镜测试技术进行了表征。研究了反应温度、反应物浓度、不同体积阴离子等对产物形貌与尺寸的影响。结果表明,单斜结构的CuC2O4多孔球直径为400～540nm,每个多孔球由50～80nm的纳米粒子自组装而成。反应物浓度及阴离子体积能调节纳米粒子的团聚尺寸,而反应温度可有效地调节多孔球的尺寸。刻蚀过程解释了CuC2O4多孔球的形成机理。     

P(St-GMA)/Fe3O4磁性聚合物微球的制备及表征

采用沉淀法制备了Fe3O4纳米粒子, 以苯乙烯(St)、甲基丙烯酸缩水甘油酯(GMA)为聚合单体, 使用分散聚合法制备了P(St-GMA)/Fe3O4磁性聚合物微球. 分析了Fe3O4粒子的形貌和结构. 研究了制备条件对磁性聚合物微球磁含量的影响. 采用FTIR, XRD, TG及TEM等手段对磁性聚合物微球的微观结构及形貌、磁含量等进行了分析表征. 研究结果表明, 制备的磁性聚合物微球粒径均一, 磁含量高达74%.     

十二烷基硫酸钠辅助下低温合成碱式碳酸镁微球

在SDS辅助下,利用氯化镁和碳酸钠溶液在较低温度下(<55℃)反应结晶直接合成碱式碳酸镁微球。利用XRD、FTIR,SEM等技术研究了SDS加入量,反应温度,反应物浓度以及NaCl浓度等合成条件对产物的影响。结果表明:在反应温度低于55℃时,控制反应物浓度小于0.20 mol.L-1,加入一定量的SDS,可以有效抑制无定形颗粒向MgCO3.3H2O生长,促使无定形纳米颗粒通过相转移与自组装直接向碱式碳酸镁4MgCO3.Mg(OH)2.4H2O转变。SDS加入量,反应温度,反应物浓度以及NaCl浓度对碱式碳酸镁微球尺寸和微观形貌均起到调节作用。     

碱金属盐LiCl对聚酰亚胺微球化的影响

以两步法为基础,采用非水乳液体系,先通过单体聚合得到聚酰胺酸溶液(PAA),然后经酰亚胺化使PI微球化,成功得到PI微球。利用傅立叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、热失重分析仪(TGA)等手段表征了PI微球的化学结构和微观形貌,探讨了在制备过程中加入碱金属盐LiCl对PI微球化形态的影响。研究结果表明,LiCl的加入使得PI微球聚集态形貌出现孔隙结构,而当LiCl浓度达到临界点时,聚合物基体的孔隙率增加,形貌呈均匀的微孔状"海绵"结构。此外,通过热分析得出,Li盐的加入对微球的热稳定性几乎没有影响。     

通过调控表面活性剂的HLB值制备具有拓扑结构的磁性聚合物微球

具有不同形貌的聚合物微球在生物和材料等领域应用广泛。目前,越来越多的研究选择以微流控技术为平台来制备聚合物微球。在这里,本文介绍了一种基于微流控技术,通过调节表面活性剂的HLB值从而制备具有拓扑结构磁性聚合物微球的方法。结果表明,不同表面活性剂的HLB值能够调控液滴的演变行为和目标微球的形貌特征。同时,该方法具备一定的普适性。这可作为制备聚合物微球的有效补充工具。     

一维CuO纳米棒的微乳-均匀沉淀耦合法制备与结构表征

以CuSO4和NH3·H2O为原料,采用微乳-均匀沉淀耦合法制备了一维CuO纳米棒。用XRD、SEM、TEM、HRTEM和FTIR对产物的结构和形貌进行了表征。结果表明:产物为单斜晶相结构的CuO纳米棒,内部具有孔洞结构,其直径为40～110nm,长度为800～3000nm。可通过改变水核比(ω)、反应物的浓度、反应时间、反应温度等条件实现对CuO纳米棒形貌和尺寸的调控。探讨了可能的反应机理,并用热分析方法考察了CuO纳米棒对高氯酸铵(AP)分解的催化作用。     

Cu2ZnSnS4纳米晶微球的制备及其表征

以乙二醇为溶剂,采用溶剂热法合成出由纳米晶组装而成的Cu2ZnSnS4(CZTS)微球。采用X射线衍射仪(XRD)、拉曼光谱仪(Raman)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见漫反射光谱(DRS)对所得微球的结构与成分、颗粒大小与形貌和光学性质进行了测试分析。研究结果表明:溶剂热法制得的CZTS粉体具有四方晶相结构,微球由纳米晶组装而成,对可见光有良好的吸收;随着反应时间的增加,颗粒尺寸逐渐增大,且对形貌有一定影响;此外,文中还对CZTS微球的形成机理做了推测。     

Synthesis, characterization and magnetic properties of hollow microspheres with micro-mesoporous shells assembled from cobalt-based ferrocenyl coordination polymers

Hollow magnetic microspheres with micro-mesoporous shells were constructed with layered cobalt-based ferrocenyl coordination polymers (Co-Fc-HCPS) through a one-step Ostwald ripening process. The diameters of microspheres and corresponding cavities were controlled in the range of several microns by tuning the reaction time and reactant concentration, which would attribute the microspheres with high loading, and enhanced mass diffusion and transfer efficiency. The high crystallinity of hollow microspheres allowed determination of the crystal structure of cobalt-based ferrocenyl coordination polymer, which crystallized in Brucite-type layered structure with the formula of Co(4)(OH)(4)(FcDC)(2), (H(2)FcDC=1,1'-ferrocenedicarboxylic acid), by combination of powder X-ray diffraction (PXRD), energy-dispersive X-ray spectroscopy (EDX), element analysis (EA), and Fourier transform infrared spectroscopy (FT-IR). N(2) adsorption/desorption investigation revealed the existence of both mesopores around 3.81 nm and micropores of ca. 1 nm in the shells. The hollow microspheres exhibited spin-canted antiferromagnetism with weak ferromagnetic ordering below ~52 K, which showed a remanent magnetization (Mr) of 1.0 μ(B) and a large coercive field (Hc) of 5 kOe at 7 K.     

Electronic and vibrational spectra of Mn rich sursassite

The optical spectrum of Mn2+ in octahedral coordination for sursassite is characterized by well resolved bands at 580, 515, 470, 390, 340, and 295 nm (17240, 19420, 21280, 25640, 29410 and 33900 cm-1). Crystal field parameters evaluated from the observed bands are Dq=690, B=680 and C=2800 cm-1. A broad band centred around 13000 cm-1 attributed to Fe(III) ion is an impurity in sursassite confirmed from EDX analysis. Vibrational spectra have been investigated both by IR and Raman spectroscopy. The correlation between vibrational modes and the structural properties of the manganese silicate, sursassite, is made and compared with other silicates. Two vibrational modes of CO(3)2- observed; the antisymmetric stretching mode (nu3) at 1420 cm-1 (IR active) and the out-of-plane bending mode (nu2) (IR and Raman active) at approximately 875 cm-1. This confirms the Mn rich phases in sursassite as observed from SEM probably an Mn carbonate-rhodochrosite.     

Studies on Monodispersed Microspheres of Zinc Sulfide Doped with Mn^2＋

In this paper,zinc acetate,manganese acetate and thiacetamide are used as raw materials to successfully synthesize monodispersed ZnS:Mn2+ microspheres by using hydrothermal method and taking P123 surfactant as a template. The products were characterized by XRD,STEM,FT-IR and N2 adsorption-desorption. And the results show that the diameter of this microsphere is 1.0 μm or so,which is larger than that of ZnS microsphere without Mn2+ doping,and it has monodispersion,smooth surface and uniform size. The doping of Mn2+ does not obviously change the structure of monodispersed ZnS microsphere. The photoluminescence peak lies in a wide band ranging from 450 to 650 nm,and the microspheres emit orange light; with the increase of Mn2+ concentration,fluorescence intensity of ZnS:Mn2+ microsphere changes,and when the mole ratio of Mn2+:Zn2+ is 0.3:1,the fluorescence intensity is the strongest.     

Synthesis, Crystal Structure and Electrochemical Properties of a One-dimensional Chain Coordination Polymer [Mn(NAA)_2(4,4’-bipy)(H_2O)_4]_n

A novel one-dimensional chain coordination polymer [Mn(NAA)2(4,4’-bipy)(H2O)4]n has been synthesized with α-naphthaleneacetic acid, 4,4’-bipy and manganese(II) sulfate as raw ma-terials. Crystal data for this complex: monoclinic, space group P21/c, a = 1.1421(2), b = 1.6337(3), c = 0.94177(19) nm, β = 112.15(3)o, V = 1.6275(6) nm3, Dc = 1.407 g/cm3, Z = 2, μ(MoKα) = 0.467 mm-1, F(000) = 722, S = 1.007, R = 0.0412 and wR = 0.1022. The crystal structure shows that two neighboring manganese(II) ions are linked together by one 4,4?-bipy molecule, and the whole complex molecule forms a one-dimensional chain structure. Each manganese(II) ion is coordinated with two oxygen atoms of two α-naphthaleneacetic acid molecules, two nitrogen atoms of two 4,4?-bipy molecules and two oxygen atoms from two water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were also analyzed.     

N -oxide bridged manganese(II) coordination polymers

A simple method for synthesis of manganese(II) coordination polymers with different benzoate ligands and pyridine N-oxide having general composition [Mn(RC₆H₄CO₂)₂(PyO)] _n is presented (where PyO = pyridine N-oxide and R = H, 1a; R = 4-NO₂, 1b; R = 4-Cl, 1c; R = 4-OH, 1d; R = 2-NO₂, 1e). All these polymers are characterized by X-ray crystallography and other spectroscopic techniques. The coordination polymers have similar structures, but the positions of the manganese atoms differ. For example, 1c is highly symmetric and a mirror plane exists between each manganese site (2/m). In 1d, the manganese centers are related by an inversion center (?1) whereas in 1e the manganese centers are related by C₁ rotation (1). Reaction of manganese(II) acetate tetrahydrate with 4-chlorobenzoic acid and PyO upon crystallization from methanol/pyridine gave crystals of coordination polymer 1c along with aqua-bis-pyridine bis-4-chlorobenzoato manganese(II) (2). The structure of 2 also determined by single-crystal X-ray diffraction has a 1-D hydrogen bonded chain structure. Temperature-dependent zero-field cooled and field-cooled magnetization data of 1a–1c measured at 20 Oe and 1000 Oe show field-dependent magnetization spread over a wide temperature range from 5 to 300 K. These coordination polymers show anti-ferromagnetic behavior below 20 K.     

Mn(Ⅱ)配位聚合物的合成、结构及光物理性能

采用水热方法合成了2种结构新颖的Mn(Ⅱ)配位聚合物,[Mn(m-tpha)(phen)]_n(1),{[Mn₃(m-tpha)₂(m-Htpha)₂(bipy)₂]·3H₂O}_n (2),(m-H₂tpha=间苯二甲酸,phen=1,10-邻菲咯啉,bipy=2,2′-联吡啶)。通过X-射线单晶衍射、红外光谱(IR)、紫外光谱(UV-Vis)、表面光电压光谱(SPS)和场诱导表面光电压光谱(FISPS)等方法对配聚物进行了表征。结构分析表明:配聚物(1)和(2)均是通过间苯二甲酸根桥连的具有1D无限结构的Mn(Ⅱ)配聚物。不同的是(1)的不对称单元中只包含1个Mn(Ⅱ)离子,它采取了N₂O₄的配位模式;而(2)的重复单元中,包含3个Mn(Ⅱ)离子,其中有2个Mn(Ⅱ)离子是晶体学等效的,它们也采取了N₂O₄的配位模式,另1个Mn(Ⅱ)离子处于一个几乎规则的正八面体场的配位环境中,6个配位原子均为O。配聚物的表面光电压光谱测试表明,它们在300～800 nm范围内都呈现正的表面光伏响应(SPV),但是光伏响应带的强度、数量是明显不同的。这是它们的结构、中心金属Mn(Ⅱ)离子的配位微环境不同所致。将配聚物的SPS与其UV-Vis光谱进行对比,可以看出SPS响应带与UV-Vis吸收峰基本是对应的。     

尺寸可控的聚苯胺复合微球的电纺制备与表征

以十二烷基苯磺酸(DBSA)掺杂的导电聚苯胺与聚乙二醇(PEG)及Fe3O4的混合氯仿溶液,采用静电纺丝(spinning technology)方法制备含Fe3O4纳米颗粒的导电聚苯胺(PANI)/PEG/Fe3O4复合微球.SEM结果表明,电纺所得的PANI/PEG/Fe3O4复合微球结构依赖于PEG聚合物浓度、静...     

沉淀聚合法制备窄分散聚(甲基丙烯酸缩水甘油酯-co-乙二醇二甲基丙烯酸酯)功能聚合物微球

以偶氮二异丁腈(AIBN)为引发剂,甲基丙烯酸缩水甘油酯(GMA)和乙二醇二甲基丙烯酸酯(EGDMA)为共聚单体,采用沉淀聚合法制备了不同交联度的窄分散聚合物微球,考察了共聚单体对聚合物微球粒度、分散性以及产率的影响,并用扫描电镜(SEM)和红外光谱对微球进行了表征,SEM结果显示当EGDMA的比例在40mol%～70mol%之间时,可得到单分散的poly-(GMA-co-EGDMA)微球.     

Synthesis and Structure of Manganese Coordinated Polymer with Regular X-shaped Cavity

A coordination polymer [Mn(IDA)2(H2o)47, (H2IDA=N-iminodiacetic acid) was synthesized and char-acterized by single crystal X-ray diffraction. The crystal belongs to the tetragonal system, the space group is P-421C with the crystal cell parameters a=0.81120(8) nm, b=0.81120(8)nm, c=0.96196(4)nm, V=0.6330(1)nm^3, Mr=355.17, R=0.0224, ωR=0.061. The four carboxylic oxygen atoms of the differentN-iminodiacetic acid ligands and two water molecules coordinate to the manganese atom. The manganeseatom is in an approximates octahedral coordination sphere. Each carboxylic acid ligand bridges two man-ganese atoms, forming two zig-zag supramolecular chains. The twisted chains construct a two-dimension lay-er structure with regularly arranged X-shaped window cavity. The three-dimension supramolecular networkis formed by coordination bonds and hydrogen bonds.     

聚苯乙烯微球表面接枝丙烯腈的研究

采用分散聚合法制备出平均粒径为3.85 μm的窄分布聚苯乙烯微球， 并在此基础上引入第二单体丙烯腈进行共聚反应， 制备出平均粒径为4.02 μm的窄分布苯乙烯-丙烯腈共聚物微球. 对聚苯乙烯微球和苯乙烯-丙烯腈共聚物微球进行了形貌及粒径、红外光谱、差示扫描量热法(DSC)分析， 结果表明丙烯腈基团均匀分布在聚苯乙烯微球表面， 提高了聚苯乙烯微球表面的极性.