Synthesis and crystal structure of a layered cobalt phosphate with a racemic 1,2-Diaminopropane template

A novel layered cobalt phosphate with racemic 1,2-diaminopropane as the templating agent, [CH₂(NH₃)-CH(NH₃)CH₃] [CoPO₄]₂, has been synthesized and structurally characterized by single-crystal X-ray diffraction methods. The compound crystallizes in the monoclinic system, space group P2₁/c with a = 10.457(2), b = 7.849(1), c = 6.692(l)?Å, β = 103.30(1)°, V = 534.5(2)?ų, Z = 2. The interaction of cobalt phosphate anionic layers and doubly protonated 1,2-diaminopropane cations is mainly ionic. The crystal structure is stabilized by a hydrogen bonding network between layers and templating cations.     

ZSM－35分子筛的合成及模板效应的研究

以1,6-己二胺为模板剂合成了ZSM-35分子筛,通过对比ZSM-35、ZSM-5和丝光沸石的合成条件,采用化学组成分析、热重分析及¹³CNMR等技术研究了1,6-己二胺和乙二胺的模板效应。结果表明,二者均对ZSM-35有较好的模板作用,而1,6-己二胺对ZMS-5的模板效应更佳。     

Sacrificial spacer and non-covalent routes toward the molecular imprinting of “poorly-functionalized” N-heterocycles

A comparison of three different methods for the imprinting of small aromatic heterocycles containing only a single nitrogen atom, for the preparation of specific analytical phases, was carried out. A conventional non-covalent approach to the imprinting of pyridine using methacrylic acid as the functional monomer was compared with two sacrificial spacer methods, in which heterocycles were imprinted as covalent template analogues. The results of binding experiments showed that discrimination based on ligand size was possible when polymers were prepared using a silyl ester-based template. The most selective polymer was able to bind pyridine in preference to quinoline or acridine which is opposite to the trend predicted by the pK_HB values for the three ligands. Curve fitting of the isotherm for pyridine binding to this polymer to the Langmuir model gave an approximate K_d of 1.1±0.1 mM and a binding site concentration of 57±2 mmol g⁻¹. Acridine binding did not show saturation behaviour and was non-specific and cooperative in nature.     

非球形聚合物粒子的合成研究

粒子的形状影响其功能性,非球形粒子作为构建单元不仅可以体现材料本身的内在性能,而且其新颖的粒子堆积类型,改善了材料性能,赋予材料更多的应用潜能。非球形粒子可用于改善材料的光学性能,用作生物材料的自组装构造单元,悬浮液流变性能的调控,制备皮克林乳液和复合材料的设计。本文综述了种子聚合法、高分子溶液混合法、机械拉伸法、微粒聚集法、微流体法和模板法等合成非球形粒子的方法,论述了非球形粒子在Pickering乳化剂,光子晶体和有序多孔材料等领域的潜在应用,并展望了可能的发展趋势。     

ZSM—5分子筛生成中的模板效应：^13C—NMR对TBA^＋体系的研究

在合成一系列ZSM-5/11分子筛的基础上,用固体高分辨~(13)C-NMR技术考察样品中模板剂TBA~+的存在状态.讨论了TBA~+在ZSM-5和ZSM-11孔道中的分布方式,并发现了TBA~+的分解产物正丁胺的存在,从而说明了在SiO_2/Al_2O_3不十分高的体系中,TBA~+和正丁胺是ZSM-5共生晶相的模板剂。     

Electrochemically Generated Recognition Sites in Self‐doped Polyaniline Modified Electrodes for Voltammetric and Potentiometric Determination of Copper(II) Ion

Chemical recognition elements for copper(II) ion have been generated in electrodes modified with poly(aniline‐co‐metanilic acid), P(An‐co‐MA), membrane and the resulting electrodes were used as selective sensors for voltammetric and potentiometric determination of this ion in an extended pH range. The P(An‐co‐MA) membrane was electrodeposited from aqueous mixed monomer solutions of An and MA, without the presence of a supporting electrolyte. For generating the recognition elements, P(An‐co‐MA) modified electrodes were subjected to several consecutive reduction/oxidation potential steps in copper(II) ion solution. It seems that during these potential steps, the receptor sites of the membrane are adjusted to the size, complexing property and hard/soft nature of copper(II) ion. This electrochemically mediated templating process, provided a selective sensor for determination of copper(II) ion. The results of preconcentration/differential pulse anodic stripping voltammetry, indicated analytical relation between the peak current and concentration of copper(II) from 1.0×10⁻⁹ to 1.0×10⁻⁴ M. The interference effect of various metal ions was explored and it was found that only mercury and silver ions show a considerable interference. The sensor exhibited selective potentiometric response for copper(II) over a wide concentration range (1.0×10⁻⁸ to 1.0×10⁻³ M) with a Nernstian slope of 27.9±0.3 mV per decade of copper(II) ion activity.     

Preparation of nanocrystalline porous titania films on titanium substrates by a sol–gel method with polyethylene glycol as a template

Porous nanocrystalline TiO₂ films have been prepared on cp-Ti substrates for biomedical usage by a sol–gel process from the solutions containing polyethylene glycol (PEG) as a template. Variations of the crystal structure with heat-treatment temperature determined by XRD are different for TiO₂ films and powders, due to the effect of titanium substrate. The surface texture of porous TiO₂ films is analyzed by means of SEM and found to greatly depend on the concentration and molecular weight of PEG. The pore formation mechanism is discussed in relation to the self-assembly of PEG and phase separation between PEG adsorbed on TiO₂ oligomers and ethanol.     

MFI-type boroaluminosilicate: A comparative study between the direct synthesis and the templating method

Boroaluminosilicate with MFI zeotype (henceforth B-ZSM-5) was synthesized both via the direct synthesis where ZSM-5 was employed as crystal seed and the templating method by using TPABr as the structure-directing agent (SDA). Characterization based on its structure, bonding, surface acidity, and morphology was performed by powder X-ray diffraction (XRD), ¹¹B MAS NMR spectrometry, FT-IR spectrometry, pyridine-chemisorption IR spectrometry, and scanning electron microscopy (SEM). The composition of the prepared zeolites was determined by ICP-AES; the zeolite framework stability was investigated by steam treatment. The differences in the physicochemical properties of B-ZSM-5 prepared by the two methods were compared and discussed. In the direct synthesis, increasing initial boron-substitution ratio concomitantly brings about increasing difficulty to prepare pure B-ZSM-5 and, MFI-type borosilicate (free of aluminum) cannot be synthesized; the highest SiO₂/Al₂O₃ ratio=70.64 is received. B-ZSM-5 prepared by the templating method shows remarkable hydrothermal stability than its counterpart prepared by the direct synthesis.     

钛硅沸石合成过程中有机胺的作用

采用四丙基溴化铵（ＴＰＡＢｒ）为模板剂，分别以正丁胺（ＮＢＡ）、己二胺（ＨＤＡ）、二乙胺（ＤＥＡ）、乙二胺（ＥＤＡ）、三丙胺（ＴＰＡ）和四乙基氢氧化铵（ＴＥＡＯＨ）调节凝胶碱度，成功地合成出ＴＳ－１沸石．采用ＩＲ，ＸＲＤ，ＵＶ－Ｖｉｓ和ＮＭＲ等表征技术，详细考察了有机胺的作用及对钛进入沸石骨架的影响．结果表明，以ＴＥＡＯＨ为碱源时抑制钛进入骨架；以ＥＤＡ为碱源时合成的钛硅沸石结晶度低；以ＴＥＡＯＨ或ＮＢＡ为碱源时合成的钛硅沸石晶粒较均匀．有机胺在ＴＳ－１合成过程中只起到调节碱度的作用，未与ＴＰＡＢｒ联合起模板作用．