六水氯化钐与甘氨酸丙氨酸三元固态配合物的热化学

合成了 Sm3 +与甘氨酸丙氨酸混配体配合物 ,通过红外光谱分析、热重分析和化学分析 ,确定了配合物的组成为 :Sm( Gly) 2 ( Ala) 3 Cl3 · 2 H2 O,并用溶解量热法分别测定了 Sm Cl3 · 6H2 O( s) ,2 Gly( s) + 3Ala( s)和 Sm( Gly) 2 ( Ala) 3 Cl3 · 2 H2 O( s)在 2 mol/L HCl中的溶解焓 ;再根据盖斯定律设计了一个热化学循环 ,计算得到了六水氯化钐与甘氨酸丙氨酸反应的反应焓△ r Hθm( 2 98.1 5 K) =2 .1 60 k J/mol,并求出了 Sm( Gly) 2 ( Ala) 3 Cl3 · 2 H2 O( s)标准生成焓△f Hθm[Sm( Gly) 2 ( Ala) 3 Cl3 ·2 H2 O,s,2 98.1 5 K]=- 44 81 .5 k J/mol     

配合物Co(p-tol)2Cl2标准生成焓的测定

使用具恒定温度环境的反应热量计,以溶解热法及针对配位反应所设计的热化学循环,得到反应的标准反应焓,并求得配合物Co(p-tol)2Cl2的标准生成焓.     

氯化镝与甘氨酸配位反应的热化学研究

用新型的具恒温环境的反应热量计 ,以 2 mol/L HCl为量热溶剂 ,分别测定了 Dy Cl3·6H2 O (s) +3Gly(s) (Gly代表甘氨酸 )和配合物 Dy(Gly) 3Cl3· 3H2 O(s)在 2 mol/L HCl溶液中的溶解焓变。根据盖斯定律设计了一个热化学循环 ,计算得到六水氯化镝与甘氨酸配位反应的反应焓Δr Hθm(2 98.2 K) =- 2 6.2 89k J/mol,并估算出配合物 Dy(Gly) 3Cl3· 3H2 O的标准生成焓 Δr Hθm(2 98.2 K) =- 3650 .5k J/mol。     

含能配合物M(BTA)(bpy)_m·nH_2O的合成及液相生成反应热动力学研究

室温下合成了6种未见报道的固态含能配合物M(BTA)(bpy)m.nH2O(M=Mn,m=1,n=1;M=Co,m=2,n=5;M=Ni,m=2,n=6;M=Cu,m=2,n=0;M=Zn,m=2,n=1;M=Pb,m=1,n=0;BTA=N,N’-二四唑胺离子,bpy=2,2’-联吡啶),对它们进行了组成、红外光谱、密度等表征。测定了298.15 K下各配合物的液相生成反应焓变△rHmθ,改变液相反应温度,在实验和计算基础上,得到了液相生成反应的热力学参数(活化焓△Hθ≠、活化熵△S≠θ和活化自由能△Gθ≠)、速率常数k和动力学参数(表现活化能E、频率因子ln[A/s]和反应级数n)。     

单羰基化反应催化剂Pd (PPh3)2Cl2的失活动力学研究

采用PAN为显色剂,通过分光光度法测定反应体系中催化剂Pd(PPh3)2Cl2的浓度,以探讨氯苄单羰基化合成苯乙酸反应中Pd(PPh3)2Cl2水解失活的动力学方程.结果表明,Pd2+与PAN显色的较佳条件为在10 mL 1～20×10-6Pd2+含量的溶液中,加入0.5 mL0.04%的PAN,在pH=3.0、40℃的水浴中加热30 min;其摩尔吸光系数e=1.384×104 L·mol-1·cm-1;Pd(PPh3)2Cl2水解反应对三苯基膦氯化钯浓度呈0.5级;对三苯基膦浓度呈-0.8级;对苯乙酸浓度呈2级;对碱中和剂NaOH的浓度呈1.2级.Pd(PPh.)2C12水解反应的活化能E=75.59 kJ·mol-1,指前因子为1.68×1012.     

晶体化合物(n-C_(12)H_(25)NH_3)_2CdCl_4(s)的制备及热化学研究

用水热合成法合成了晶体化合物(n-C12H25NH3)2Cd Cl4(s);根据热化学原理计算了化合物(n-C12H25NH3)2Cd Cl4(s)的晶格能为889.81 k J·mol-1。利用等温溶解-反应热量计,得到了该化合物的标准的摩尔焓:[(n-C12H25NH3)2Cd Cl4,s]=-(1836.23±7.95)k J·mol-1。     

配位化合物Cu(p-tol)2Cl2标准生成焓的测定

使用具有恒定温度环境的反应热量计,以溶解热法及针对配位反应所设计的热化学循环,得到该反应的标准反应焓△ｒＨθｍ（２９８．１５Ｋ）＝－２７．９２４ｋＪ·ｍｏｌ－１,并求得配合物Ｃｕ（ｐ－ｔｏｌ）２Ｃｌ２的标准生成焓,其值推荐为△ｆＨθｍ［Ｃｕ（ｐ－ｔｏｌ）２Ｃｌ２,ｓ］＝－３４３．３７４ｋＪ·ｍｏｌ－１。     

氯化镍与2-氨基嘧啶配合物的量热法研究

制备了2-氨基嘧啶(AP)与镍的配合物Ni(AP)2Cl2,并对其组成进行了测定,采用具有恒温环境的溶解-反应量热计,分别测定了298.15 K时[NiCl2.6H2O(s) 2AP(s)]和Ni(AP)2Cl2(s)在100.00 mL 2 mol/L HCl溶液中的溶解焓。通过设计热化学循环得到2-氨基嘧啶(AP)和氯化镍反应的反应焓ΔrHmΘ=21.17±0.09 kJ/mol,进而计算出配合物Ni(AP)2Cl2在298.15 K时的标准摩尔生成焓为ΔfHΘm[Ni(AP)2Cl2,(s),298.15 K]=-458.82±3.41 kJ/mol.     

NTO负一价离子的水合Gibbs自由能和水合熵变及体系[Mn+(g)+nNTO-(g)+mH2O(g)]水合过程的焓变

提出了一个估算NTO负一价离子标准水合Gibbs自由能ΔhGθm(NTO-,g)的简易公式.用所建立的估算式和热力学关系式,算得ΔhGθm(NTO-,g)＝-267.24kJ·mol-1,ΔhSθm(NTO-,g)＝380.71J·(K·mol)-1.用热化学循环,算得体系[Mn (g) nNTO-(g) mH2O(g)](M=La,Ce,Pr,Eu,Sm,Gd,n=3,m=7;M=Y,Yb,n=3,m=6;M=Dy,Tb,n=3,m=5;M=Nd,n=3,m=8)水合过程的焓变.     

α-、β-环糊精与季铵盐型表面活性剂的包合作用研究

在298.15 K下,用滴定式微量热法对α-、β-环糊精(α-/β-CD)与两个新型同系列表面活性剂3-烷氧基-2-羟丙基三甲基氯化铵(CnNC l,n=8,12)的包合作用进行了研究。结果表明,C8NC l与α-/β-CD均形成摩尔比为1∶1的稳定包合物,实验稳定常数分别为1.41×103dm3.mol-1和6.50×102dm3.mol-1;而C12NC l与α-/β-CD分别形成摩尔比为1∶2和1∶1的包合物,实验稳定常数分别为1.05×106dm6.mol-2和8.83×103dm3.mol-1。具有较长疏水链的C12NC l与两类环糊精包合过程的标准焓变(ΔHθ)和标准熵变(ΔSθ)较小。α-CD包合物的形成过程是焓驱动熵阻滞,而β-CD包合物的形成过程则是熵焓共同驱动。     

Crystallization of zeolite L from Na2O-K2O-Al2O3-SiO2-H2O system

Zeolite L powder was prepared from the substrate mixture of Na₂O-K₂O-Al₂O₃-SiO₂-H₂O system at temperatures of 373-443 K. In order to investigate the factors which influence the synthesis outcome, a reference system which yields zeolite L in a reproducible manner was chosen and subjected to controlled changes in synthesis parameters. The crystalline zeolite L samples obtained were characterized by elemental chemical analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). It was established that phase purity, morphology, and the size of crystals of crystalline product were affected by molar ratios of the substrate, such as SiO₂/Al₂O₃, (K₂O+Na₂O)/SiO₂, Na₂O/(K₂O+Na₂O), and H₂O/(K₂O+Na₂O). Amorphous silica powder (Zeosil) was the preferred silica source, and the crystallization rate was promoted by introducing gel aging, seeding, and rapid heating rate.     

Photocatalytic activity of Cu2O/TiO2, Bi2O3/TiO2 and ZnMn2O4/TiO2 heterojunctions

Cu₂O/TiO₂, Bi₂O₃/TiO₂ and ZnMn₂O₄/TiO₂ heterojunctions were studied for potential applications in water decontamination technology and their capacity to induce an oxidation process under VIS light. UV–vis spectroscopy analysis showed that the junctions-based Cu₂O, Bi₂O₃ and ZnMn₂O₄ are able to absorb a large part of visible light (respectively, up to 650, 460 and 1000 nm). This fact was confirmed in the case of Cu₂O/TiO₂ and Bi₂O₃/TiO₂ by photocatalytic experiments performed under visible light. A part of the charge recombination that can take place when both semiconductors are excited was observed when a photocatalytic experiment was performed under UV–vis illumination. Orange II, 4-hydroxybenzoic and benzamide were used as pollutants in the experiment. Photoactivity of the junctions was found to be strongly dependent on the substrate. The different phenomena that were observed in each case are discussed.     

碳酸钠—过氧化氢—水体系相图的绘制

进行了Na2CO3-H2O2-H2O体系溶解度的测定并绘制成相图,最后对其应用进行了讨论。     

Synthesis and characterization of Y2O3-ZrO2 and Y2O3-CeO2-ZrO2 precursor powders

Thixotropic gels of the precursor powders of the titled compounds have been prepared by the addition of oxalic acid to the mixed solutions of metal salts at room temperature (≈ 27 °C). The clear sols of yttrium-zirconyl oxalate (YZO) and yttrium-cerium-zirconyl oxalate (YCZO) gelled within a few hours and were oven-dried at 40 °C. The various stages of gelation behaviour of the sols are explained on the basis of DLVO theory. By repeptizing the dried gel powders with water, concentrated sols were prepared. The gelation time as a function of chloride ion concentration is discussed for both sols. The nature of the temperature dependence of the dried gel powders was studied by means of thermogravimetric analysis and differential thermal analysis. Powder X-ray diffraction was used to study the crystallization behaviour of the dried amorphous gel powders. It is found that these powders crystallize in tetragonal phase when calcined at 850 °C for 1 h. Estimation of surface area and infra-red characterization have also been carried out for the prepared powders.     

Preparation and characterization of Cr2O3-TiO2-Al2O3-V2O5 green pigment

Green pigments with high near infrared reflectance based on a Cr₂O₃-TiO₂-Al₂O₃-V₂O₅ composition have been synthesized. Cr₂O₃ was used as the host component and mixtures of TiO₂, Al₂O₃ and V₂O₅ were used as the guest components. TiO₂, Al₂O₃, and V₂O₅ were mixed into 39 different compositions. The spectral reflectance and the distribution of pigment powder were determined using a spectrophotometer and a scanning electron microscope, respectively. It was found that a pigment powder sample S9 with a Cr₂O₃-TiO₂-Al₂O₃-V₂O₅ composition of 80, 4, 14 and 2 wt%, respectively, gives a maximum near infrared solar reflectance of 82.8% compared with 49.0% for pure Cr₂O₃. The dispersion of pigment powders in a ceramic glaze was also studied. The results show that the pigment powder sample S9 is suitable for use as a coating material for ceramic-based roofs.     

Al2O3-SiO2-TiO2一ZrO2复合陶瓷膜的制备与表征

采用Sol—Gel法制备出掺杂SiO2，TiO2及ZrO2改性的γ-Al2O3膜，并通过SEM，EPMA，AFM等测试手段对膜结构和性能进行表征。探讨了制膜工艺条件对膜性能及结构的影响。制备的Al2O3复合膜膜厚为1—2μm，结构均匀无缺陷。     

Crystal Structure of the LiNaZnP2O7 Compound in the Li2ZnP2O7-Na2ZnP2O7 Glass-Forming System

The crystal structure of the LiNaZnP₂O₇ compound is determined using X-ray powder diffraction (space group Cmcm, a = 12.431 Å, b = 7.589 Å, c = 6.283 Å). The structure has a mixed tetrahedral framework consisting of the diortho groups [P₂O₇] and the tetrahedra [ZnO₄] and [LiO₄], which are joined into chains. The [ZnO₄] and [LiO₄] tetrahedra are distributed in the chains in a random manner, because the zinc and lithium atoms statistically occupy one crystallographic position. The sodium cations are arranged in channels of the tetrahedral framework. The atomic coordinates and interatomic distances in the structure are reported. Original Russian Text Copyright ? 2005 by Fizika i Khimiya Stekla, Shepelev, Lapshin, Petrova, Novikova.     

Stable Ti/RuO2-Sb2O5-SnO2 electrodes for O2 evolution

RuO₂-based electrodes are generally known to be unstable for O₂ evolution. In this paper, a stable type of RuO₂-based electrode, Ti/RuO₂-Sb₂O₅-SnO₂, is demonstrated for O₂ evolution. In the ternary oxide coating, RuO₂ serves as the catalyst, SnO₂ as the dispersing agent, and Sb₂O₅ as the dopant. The accelerated life test showed that the Ti/RuO₂-Sb₂O₅-SnO₂ electrode containing 12.2 molar percent of RuO₂ nominally in the coating had a service life of 307 h in 3 M H₂SO₄ solution under a current density of 0.5 A cm⁻² at 25 °C, which is more than 15 times longer than other types of RuO₂-based electrodes. Instrumental analysis indicated that RuO₂-Sb₂O₅-SnO₂ was a solid solution with a compact structure, which contributed to the stable nature of the electrode.     

Investigation of the crystallization of zeolites in the SiO2-Al2O3-Na2O-K2O-(TEA)2O-H2O system

The crystallization of zeolites in the SiO₂-Al₂O₃-Na₂O-K₂O-(TEA)₂O-H₂O system, where (TEA)₂O is tetraethylammonium oxide, has been investigated over a wide range of variations in the SiO₂: Al₂O₃ ratio (from 5 to 19). It has been found that, in the composition region under investigation, zeolites crystallize with structures of paulingite, beta, phillipsite, merlinoite, erionite, mordenite, and garronite. The formation of the aforementioned phases is determined by the composition of the initial gels and the synthesis temperature. The cocrystallization of paulingite, phillipsite, and merlinoite is explained by the structural features of these zeolites.