胆固醇(Cholesterol)嵌入卵磷脂(PC)有序体后对其中CaCO3晶型结构的影响

在PC和Chol/PC有序体中进行CaCO₃沉淀反应,用X射线衍射和扫描电镜方法表征了反应物结构,研究了作为有机模板剂的不同分子有序体对CaCO₃的晶型和形态的指导作用.在反胶束合成中出纳米级CaCO₃颗粒.胆固醇对有序体有显著影响,进而影响此体系中形成的CaCO₃晶型,可诱导生成3种CaCO₃异构体:胶体CaCO₃、球霰石和方解石.方解石含量随胆固醇含量增加减少.     

胆固醇对卵磷脂有序体中生成CaCO3晶型的影响

报道了在卵磷脂、胆固醇、橄榄油、电解质溶液组成的分子有序组合体中,胆固醇的加入影响了有序体的膜结构、表面特性,从而也影响到有序体微环境中所生成的CaCO₃晶体结构。随着胆固醇含量增加,在一定范围内球霰石的相对含量增大;油包水体系中生成的球霰石相对含量远大于水包油体系中生成的球霰石相对含量。     

2,2’-联苯二酸和温度对CaCO_3晶型的影响

分别在90℃和120℃下,用2,2’-联苯二酸(bpdca)作为调控剂合成了具有不同晶型和形状Ca CO3晶体,研究羧酸浓度和温度对Ca CO3晶型和形貌的影响。用粉末衍射XRD、FT-IR表征了合成的产物,用扫描电子显微镜(SEM)观察研究了产物粒子的形状,调查研究了温度和bpdca浓度对Ca CO3粒子形貌和晶型的影响。结果表明,bpdca和温度均会对Ca CO3的晶型和形状有影响。     

溶剂和溶液酸碱性对碳酸钙晶型和形状影响研究

<正>CaCO3主要有三种晶型:方解石,文石和球霰石[1-3],方解石是CaCO3晶体最稳定的晶型,球霰石是最不稳定的,文石的稳定性介于两者之间。在生物矿物中经常发现有文石和方解石的存在,具有结构功能和光学等性能[4],是生物体硬组织中的主要无机成份之一。在珍珠、贝壳、甲壳、动物骨骼等生物组织中CaCO3与少量有机基质(生物大分子)结合,形成具有特定性质的有机/无机杂化材料[5],例如,方解石存在于骨头,牙齿等硬组织中,另外还具有在神经束中的光聚焦功能;     

卵磷脂-水-油酸体系液晶对胆固醇的增溶作用

Formation and structure of liquid crystal in lecithin-water-oleic acid system were studied. It was found that different from the lecithin-water system, there are two types of liquid crystal present. The lamellar liquid crystal was formed at lower content of oleic acid, the values of interlayer spacing are larger than the values in the corresponding liquid crystal without oleic acid. The inverse hexangonal liquid crysta1 was formed at higher content of oleic acid. In lecithin-water-oleic acid(containing 15℅ cholesterol) system the phase behavior of liquid crystal is similar to that in the lecithin-water-oleic acid system. The solubilization rate of solid cholesterol in lamellar liquid crystal of lecithin-water-oleic acid system is more faster than that of lecithin-water system.     

鲫鱼牙齿提取液对碳酸钙晶型和形貌的影响

25℃下,在鲫鱼牙齿提取液存在时,用Na_2CO_3和Ca(NO_3)_2·4H_2O作为原料合成碳酸钙,研究提取液的浓度和反应时间对产物组成和粒子形貌的影响。用粉末X-射线衍射仪(XRD)和红外光谱仪(FT-IR)对合成的产品进行了表征,用扫描电子显微镜(SEM)观察了粒子的形貌。研究结果显示,在反应时间是30s时,合成得到的产物是球霰石晶型和方解石晶型的混合物,并且随着提取液浓度的增加,球霰石所占比例呈现增加趋势;随着反应时间的增加,球霰石的含量会降低,但是产物粒子的形貌没有明显变化。结果说明,提取液的确能够影响碳酸钙的晶型和粒子形貌。     

W/O、O/W型卵磷脂乳状液对CaCO3晶型的影响

Ｗ／Ｏ、Ｏ／Ｗ型卵磷脂乳状液对ＣａＣＯ３晶型的影响姚松年＊缪炜童华张操墨熊海涛（武汉大学分析测试科学系，武汉４３００７２）关键词：卵磷脂乳状液ＣａＣＯ３碳酸钙可以方解石、霰石、球霰石、胶状碳酸钙等形态存在且依次稳定性降低。珍珠是生物矿化产物，除氨基酸...     

醇-水混合溶剂中双亲水嵌段共聚物对CaCO3粒子形貌的调控

合成形态、大小及结构受到人为调控的无机材料是现代材料科学的一个重要研究方向, 通过生物模拟方法可望实现各类有机添加剂及模板对无机物形貌与结构的有效调控[1,2]. 近年来, 一类新型的无机晶体生长调控剂--双亲水嵌段共聚物[3]已成功地用于多种无机粒子形貌的有效调控. 双亲水嵌段共聚物由2个与无机表面亲和作用不同的亲水链段构成, 在其水溶液中, 已实现了具有一系列特殊形貌的碳酸钙[4~6]、磷酸钙[7]及硫酸钡[8]粒子的生物模拟合成. 人们已陆续报道了在多种有机添加剂及模板作用下典型的生物矿物CaCO3的生物模拟合成[9,10]. 我们曾系统地研究了水溶液中双亲水嵌段共聚物对CaCO3粒子形貌的调控作用[6],最近又在双亲水嵌段共聚物-表面活性剂混合溶液中合成出具有新颖形貌(如空壳状等)的CaCO3粒子[11]. 本文考察了醇-水混合溶剂中双亲水嵌段共聚物对CaCO3粒子形貌的调控作用, 初步揭示了溶剂特性对该调控作用的显著影响.     

纳米CaCO3改性对医用胶乳制品的影响

纳米CaCO3是20世纪80年代发展起来的一种新型超细固体材料。由于纳米CaCO3的超细微化，其晶体结构和表面电子结构发生变化，产生普通碳酸钙所不具有的量子尺寸效应、小尺寸效应、表面效应和宏观量子效应。也由于纳米CaCO3的超细微化，使其自身存在难以克服的缺点——附聚形成二次结构。如果附聚粒子最终不能被碾碎后分散，就会潜伏下来，成为应力集中点，最终导致改性材料性能的下降，欲充分发挥纳米CaCO3的纳米效应，有必要研究其填充改性的影响因素，从而确立纳米CaCO3填充改性的最佳参数。实验证明：纳米CaCO3表面状态、含量、表面处理剂用量、纳米CaCO3表面活化改性时搅拌时间都对纳米CaCO3填充改性的效果产生影响。     

双亲水性嵌段共聚物对CaCO3结晶的影响

以合成的带有磺酸基为端基的线型-超支化二嵌段共聚物PEG-b-PEI-SO3H为模板,探讨了其对CaCO3结晶的影响,并用FTIR、XRD、SEM、TEM等对产物进行了表征.结果表明,带有—SO3H端基的线型-超支化双亲水性嵌段共聚物PEG-b-PEI-SO3H对CaCO3晶体形貌和晶型表现出较强的调控能力.培养1天时得到空心环状方解石型CaCO3晶体,但当培养时间为3天和5天时,得到的CaCO3晶体形貌既有河蚌状也有类球状,同时其晶型既有方解石也有球霰石,而当培养时间达到7天后,得到的就只有球状球霰石CaCO3晶体.     

配合物Nd(C7H7N2O2)3(H2O)3的合成及其晶体结构

用水热法合成了3,5-二氨基苯甲酸与Nd(Ⅲ)的配合物Nd(C7H7N2O2)3(H2O)3(1),其结构经IR,元素分析和X-射线单晶衍射仪表征。1为单核结构,属六方晶系,R3空间群,晶胞参数:a=1.887 29(18)nm,b=1.887 29(18)nm,c=0.603 53(12)nm,β=90,°γ=120°,V=1.861 7(4)nm3,Z=3,μ=2.154 mm-1,Dc=1.744 g.cm-3,R1=0.014 3,wR2=0.033 2。1中Nd(Ⅲ)与来自3个3,5-二氨基苯甲酸的6个氧原子及3个配位水的氧原子进行配位,形成9配位化合物。     

Synthesis and Crystal Structure of 3-(Pyrrole-2''-carboxamido)propanoic Acid·(1/2)H2O

3-(Pyrrole-2'-carboxamido)propanoic acid I has been synthesized from the reaction of β-alanine methyl ester with 2-trichloroacetylpyrrole followed by saponifying and acidating in 85.4% yield, and the crystal structure of 3-(pyrrole-2'-carboxamido)propanoic acid· (1/2)H2O (C8H11N2O3.5, Mr = 191.19) was obtained and determined by X-ray diffraction method. The crystal is of monoclinic, space group C2/c with a = 19.010(4), b = 8.3515(17), c = 13.788(3) (A), β = 125.88(3)°, V = 1773.6(6) (A)3, Z = 8, Dc = 1.432 g/cm3, λ = 0.71073 (A), μ-MoKα) = 0.114 mm-1 and F(000) = 768. The structure was refined to R = 0.0354 and wR = 0.0942 for 1642 observed reflections with I > 2σ(I). It is revealed that the title compound has one pyrrole ring and one propionic acid subchain linked by an amido bond at C(4), and there are 8 molecules of com- pound I and 4 crystal water molecules in each unit cell. The supramolecular layers are stabilized by the hydrogen bonds of N(2) H…O(2), N(1) H…O(4), O(4) H(1W)…O(2) and O(3) H…O(1).     

［La（EO_3）_3（H_2O）］（ClO_4）_3·H_2O的晶体结构

稀土高氯酸盐开环冠醚三缩乙二醇（ＥＯ_３）［Ｌａ（Ｃ_６Ｈ_（１４）Ｏ_４）_３（Ｈ_２Ｏ）］（ＣｌＯ_４）_３·Ｈ_２Ｏ，单斜晶系，Ｐ２_１／ｃ空间群。晶胞参数为：ａ＝１５．４７４（２），ｂ＝１１．３８６（１），ｃ＝２０．８４１（４），β＝９９．８２（１）°，Ｖ＝３６１８（１），ＭｏＫα，Ｚ＝４，Ｄ_ｃ＝１．７１８ｇ／ｃｍ３，μ＝１．４９９ｍｍ￣（－１）。全矩阵最小二乘精细修正，结构因子Ｒ＝０．０５６，Ｒ_ｗ＝０．０８３。中心原子Ｌａ与开环冠醚醚链上的Ｏ（１）～Ｏ（９）及一个水分子形成１０配位双帽四方反棱柱结构。弱配体高氯酸根不参加配位。     

Synthesis and Crystal Structure of 3-(Pyrrole-2′-carboxamido)propanoic Acid·(1/2)H_2O

1 INTRODUCTION Pyrrole and its derivatives have attracted much attention due to their chemical properties as well as biological activities[1]. They have been widely used to produce pharmaceutical, essences, biochemicals, etc. It has been found that a great number of pyrrole derivatives present antitumor and antiviral activi- ties[2 ~ 5]. During our searches for bioactive com- pounds, a series of pyrrole derivatives were synthe- sized[6, 7]. We report here the synthesis of 3-(pyrrole- 2?-…     

[{Zn(3-SBA)(2,2''''-bipy)(H2O)2}·H2O]n的合成和晶体结构研究

具有层状结构的无机-有机杂化复合聚合物材料有广泛的应用前景,它引起化学工作者的浓厚兴趣,成为一个热门的研究领域[1～3].众所周知,这类聚合物具有许多特殊的性能,在新功能材料(如选择性催化材料、分子识别材料、超高纯度分离材料、光电材料、新型半导体材料、磁性材料)开发中显示了诱人的应用前景[4～6].类似于有机磷酸化合物,有机磺酸已被报道易同多种金属形成各种各样具有层状或者柱层状的化合物,这些金属包括碱金属、碱土金属、过渡金属及镧系金属[7～9].多种官能团如-NH2、-OH、-COOH和-SO3H一起形成一类新型的无机-有机杂化复合聚合物材料.文献中报道的配体有4-羧基苯磺酸[7]、3,5-二羧基苯磺酸[10]、1,4-苯二磺酸[11].到目前为止,使用3-羧基苯磺酸作为配体的还未见报道,本文使用3-羧基苯磺酸作为配体与ZnSO4·H2O和2,2'-联吡啶反应合成了一个层状Zn配合物.用IR和元素分析对配合物进行了表征,用X-射线单晶衍射测定了该配合物的单晶结构,并对该配合物的荧光性质进行了研究.     

Growth and Crystal Structure of YbAl3（BO3）4

1 INTRODUCTION With the development of high power InGaAs laser diode (LD) as pump sources, the Yb3+-doped laser crystals have received much attention. Due to the simple energy level structure of the Yb3+ ions, the Yb3+-doped laser crystals have no concentration quenching, and have high quantum efficiency and low quantum defects even at high doping concentration of the Yb3+ ions[1, 2]. Therefore, the Yb3+-doped crystals are good candidates of media in the LD-pumped solid-state laser,…     

一维链状配位聚合物[Cu3(TFSSB)2·(H2O)4·4H2O]n的合成和晶体结构

The title complex [Cu₃(TFSSB)₂·(H₂O)₄·4H₂O]_n (TFSSB=taurine 3-formylsalicylic schiff base) was synthesized by TFSSB and copper(Ⅱ) acetate monohydrate in ethanol solution and the crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic system, space group P2₁ / n，with cell parameters: a=0.927 9(6) nm, b=1.173 0(2) nm, c=1.471(2) nm, β=106.96(2)°, and V=1.531(2) nm³, Z=2, D_c=1.890 g·cm^-3, μ=2.291 mm^-1, F(000)=882, R₁=0.025 9, wR₂=0.065 9. The Cu1 is five-coordinate, the Cu2 is four-coordinate. CCDC: 253298.     

Synthesis and Crystal Structure of a 2D Coordination Polymer： [Nd2（PDB）2（CH3COO）2（H2O）3]

A novel coordination polymer [Nd2（PDB）2（CH3COO）2（H2O）3] （H2PDB = pyridine3,4-dicarboxylic acid） has been synthesized by the reaction of Nd（CH3COO）3 with pyridine3,4-dicarboxylic acid under hydrothermal conditions. Elemental analysis, IR spectra and X-ray crystal structure analysis were carried out to determine the composition and crystal structure of the title complex which belongs to the triclinic system, space group P^-1 with a = 6.9409（14）, b = 7.5497（15）, c = 22.530（5）A, α = 84.79（3）, β = 88.15（3）, γ= 75.55（3）^o, C18H18N2O15Nd2, Mr = 790.82, Z = 2, V = 1138.5（4） A^3, Dc = 2.307 g/cm^3,μ = 4.593 mm^-1, -6≤h≤8, -5≤k ≤8, -26≤l≤ 26, F（000） = 760, Rint = 0.0298, R= 0.0314 and wR= 0.0695 （I〉 2σ（I））. Nd（1） and Nd（2） are linked into zigzag chains by carboxylate groups of acetate with interesting μ3-η^2：η^2 fashion. The zigzag chains are bridged by PDB to form a 2D framework, and a 3D supramolecular network is further constructed via π-π stacking.