铜掺杂对金纳米棒生长及光学性质的影响

采用金-铜共混法制备了金纳米棒,研究了铜离子存在下金纳米棒的等离子体共振吸收及形貌的变化.通过调节反应中铜离子的加入量及晶体生长过程中各反应参数,使金纳米棒复合纳米材料的形貌、长径比和光学性质得到有效控制.比较了纯金纳米棒与掺入铜的金纳米棒的光热转换性能和拉曼光谱的增强性能.结果表明,铜离子的掺杂可以有效控制金纳米棒的生长以及金纳米棒的形貌.加入铜离子的金纳米棒的光热转换效率明显低于单纯的金纳米棒,但是铜掺杂的金纳米棒在被用作拉曼基底时,表面增强拉曼性质却优于纯金纳米棒.     

金纳米棒的表面改性及与H_2O_2的作用

通过调控过氧化氢与金纳米棒相互作用时溶液的H~+和Br~-浓度,考察了过氧化氢刻蚀金纳米棒的条件.通过静电相互作用将聚苯乙烯磺酸钠修饰到带正电的金纳米棒表面,并探讨了表面配体变化对过氧化氢与金纳米棒相互作用的影响,比较了聚苯乙烯磺酸钠浓度改变对过氧化氢刻蚀金纳米棒所引起的等离子体吸收峰的变化.结果表明,过氧化氢与金纳米棒作用过程中,H~+浓度增加可以加快刻蚀反应速率,Br~-起到稳定金离子的作用.采用聚苯乙烯磺酸钠修饰抑制了过氧化氢对金纳米棒的刻蚀,当聚苯乙烯磺酸钠与金纳米棒表面的CTAB完全作用后,复合材料电位接近零,金纳米棒的稳定性降低,继续增加聚苯乙烯磺酸钠的量至电位为负,复合材料稳定性增加.     

基于金纳米棒的生物检测、细胞成像和癌症的光热治疗

由于金纳米棒颗粒独特的可调的表面等离子共振特性,使得金纳米棒颗粒在纳米复合材料和功能化纳米器件的构建、纳米生物技术、生物医学等领域具有广泛而重要的应用前景。本文综述了金纳米棒颗粒的生物检测、细胞成像和癌症的光热治疗方面的最新研究进展,并介绍了金纳米棒颗粒的光学性质和金纳米棒颗粒和几种主要的表面修饰方法,对金纳米棒颗粒在生物应用过程中存在的主要问题进行了讨论。     

金纳米棒在超疏水表面的组装行为研究

采用了"烟囱效应"以及超疏水表面作为基底这两项外力作用来将金纳米棒进行组装。借用"烟囱"技术的侧面向心力所产生的向心空气气流,以及超疏水表面上液滴收缩产生的应力对纳米粒子的向心挤作用,得到了金纳米棒垂直于基片致密排列的特殊的组装花样以及金纳米棒水平短程有序的致密排列的组装花样。这种简便的组装方法不仅对纳米器件的应用有着重要的影响,而且可以广泛地适用于其他的纳米粒子的二维有序组装以得到不同的功能性的纳米组装体。     

金纳米星的制备、表面修饰及其在生物医学领域的应用研究

随着纳米技术的飞速发展,复杂三维结构的金纳米星已成为一种新型纳米材料。金纳米星具有独特的物理化学性质,如可调制的LSPR光学特性、SERS效应、光热特性、较大的比表面积等,这些性质使其在纳米材料和生物医学领域具有极高的潜在应用价值。本文首先介绍了金纳米星独特的光学性质,并对这些光学特性的理论基础进行解释;接着对近年来国内外制备金纳米星的主要方法进行阐述,主要包括种子介导生长法和一步合成法,这两种制备方法均存在各自的优缺点。在功能化的探针构筑方面,金纳米星的表面修饰主要包括两种方法：二氧化硅包裹金纳米星和高分子聚合物或生物分子修饰金纳米星。在应用方面,本文对金纳米星在生物分子检测、医学成像、肿瘤的诊断与光热治疗、药物传输和控制释放方面的最新研究进展进行了总结。最后,对目前金纳米星探针在制备和应用中存在的一些问题进行了探讨,并展望了该领域未来的研究内容和方向。     

聚乙二醇-金纳米棒介导的近红外光热抑菌作用

种子生长法合成纵向表面等离子体共振吸收峰为785 nm的金纳米棒,并对其表面进行聚乙二醇(PEG)修饰,研究了表面修饰PEG的金纳米棒(polyethylene glycol modified gold nanorods,PEG-GNR)的光热转化效应,并测试了其细胞毒性.以革兰氏阳性菌金黄色葡萄球菌、蜡状芽孢杆菌,革兰氏阴性菌大肠埃希氏菌及铜绿假单胞菌为细菌模型,详细研究了PEG-GNR在808 nm波长近红外激光照射下金纳米棒浓度和照射功率对抑菌效果的影响.结果表明,PEG-GNR对革兰氏阳性菌和革兰氏阴性菌在近红外照射下均有较好的抑菌效果,并且抑菌效果与金纳米棒的浓度和照射功率有着密切的关系;结合荧光显微镜和透射电子显微镜对细菌坏死状况的观察,初步证实细菌对PEG-GNR有效吸收是近红外光热杀菌的关键因素.     

适体功能化的金纳米棒用于癌症靶向治疗的研究进展

金纳米棒(gold nanorods,GNRs)具有特殊的光学性质、较大的比表面积、出色的光热转换性能、表面易修饰等特点,在药物递送、光疗、生物成像和化学传感等领域应用十分广泛。适体是短的单链DNA或RNA片段,可特异性识别癌细胞或其表面的膜蛋白。近年来,适体功能化的GNRs在癌症靶向治疗领域显示出良好的应用前景。根据GNRs对癌症作用机制的差异,本文从光热疗法、光动力疗法、化疗和联合疗法4个方面总结了适体功能化的GNRs在癌症靶向治疗中的最新进展,并对该领域面临的主要挑战和发展趋势进行了探讨与展望。     

蜂毒素在功能化金纳米粒子表面的吸附及构象变化

利用硼氢化钠还原法制备了金纳米粒子, 通过在其表面修饰链长不同的巯基羧酸, 得到了功能化纳米粒子. 利用荧光发射、紫外吸收和圆二色谱等手段研究了功能化金纳米粒子与蜂毒素分子之间的相互作用及其所诱导的蛋白质分子的构象变化. 研究结果表明, 功能化修饰的金纳米粒子可通过静电相互作用吸附蜂毒素(Melittin)并诱导其α-螺旋结构的形成, 且这种效应与巯基羧酸分子的链长直接相关.     

聚乙二醇-金纳米棒介导的近红外光热抑菌作用

种子生长法合成纵向表面等离子体共振吸收峰为785 nm的金纳米棒,并对其表面进行聚乙二醇(PEG)修饰,研究了表面修饰PEG的金纳米棒(polyethylene glycol modified gold nanorods,PEG-GNR)的光热转化效应,并测试了其细胞毒性。以革兰氏阳性菌金黄色葡萄球菌、蜡状芽孢杆菌,革兰氏阴性菌大肠埃希氏菌及铜绿假单胞菌为细菌模型,详细研究了PEG-GNR在808nm波长近红外激光照射下金纳米棒浓度和照射功率对抑菌效果的影响。结果表明,PEG-GNR对革兰氏阳性菌和革兰氏阴性菌在近红外照射下均有较好的抑菌效果,并且抑菌效果与金纳米棒的浓度和照射功率有着密切的关系;结合荧光显微镜和透射电子显微镜对细菌坏死状况的观察,初步证实细菌对PEG-GNR有效吸收是近红外光热杀菌的关键因素。     

功能化金纳米修饰电极自组装及其在固定化酶生物传感器中应用

功能化金纳米修饰电极是化学修饰电极,不仅具有特定功能团性能,且能提供电化学信号,可用于与待测物的电子传递,电子捕获,判定某化学反应是否发生.功能化金纳米修饰电极检测待测物,具有灵敏度高、检测限低及长久使用的优势.我们就功能化金纳米修饰电极自组装制备、电化学表征方法及其在固定化酶生物传感器方面的应用研究,进行综述报道.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von vier bindungsisomeren Trichlorotrirhodanoosmaten(IV)

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of four Linkage Isomeric Trichlorotrirhodanoosmates(IV) By treatment of fac-[OsCl₃I₃]^2? with (SCN)₂ in dichloromethane the linkage isomers fac-[OsCl₃(NCS)₃]^2? ( 1 ), mer-[OsCl₃(NCS)₂^c(SCN)]^2? ( 2 ), mer-[OsCl₃(NCS)(SCN)₂^t]^2? ( 3 ), and mer-[OsCl₃(NCS)(SCN)₂^c]^2? ( 4 ) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. X-Ray structure determinations have been performed on single crystals of fac-(Ph₄As)₂[OsCl₃(NCS)₃] (triclinic, space group P1 , a = 12.142(5), b = 13.233(5), c = 19.300(5) Å, α = 98.642(5)º, β = 100.509(5)º, γ = 112.514(5)º, Z = 2), mer-(Ph₄As)₂[OsCl₃(NCS)₂^c (SCN)] · acetone (triclinic, space group P1 , a = 11.707(5), b = 13.238(5), c = 19.048(5) Å, α = 75.960(5)º, β = 88.981(5)º, γ = 69.999(5)º, Z = 2), mer-(Ph₄As)₂[OsCl₃(NCS)(SCN)₂ ^t] (triclinic, space group P1, a = 10.6861(12), b = 11.6587(5), c = 12.5232(5) Å, α = 112.069(8)º, β = 95.052(8)º, γ = 92.559(7)º, Z = 1) and mer-(Ph₄As)₂[OsCl₃(NCS)(SCN)₂ ^c] · 2acetone (triclinic, space group P1 , a = 11.444(5), b = 14.661(5), c = 15.830(5) Å, α = 75.790(5)º, β = 80.273(5)º, γ = 75.205(5)º, Z = 2). The complex anions are completely ordered. The via N or S coordinated thiocyanate groups are located nearly direct above one of the cis-positioned Cl ligands with Os? N? C angles of 169.1º, 171.5º, 175.7º ( 1 ), 175.6º, 178.6º ( 2 ), 172º ( 3 ), and 173.1º ( 4 ) and Os? S? C angles of 106.2º ( 2 ), 106.1º, 106.6º ( 3 ), 105.1º, and 108.2º ( 4 ). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salts of all four linkage isomers have been assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are f_d(OsN) = 1.71 ( 1 ), 1.46 and 1.62 ( 2 ), 1.69 ( 3 ), and 1.61 ( 4 ), f_d(OsS) = 1.27 ( 2 ), 1.36 ( 3 ), 1.32, and 1.49 mdyn/Å ( 4 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von vier bindungsisomeren Tetrachlorodirhodanoosmaten(IV)

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of Four Linkage Isomeric Tetrachlorodirhodanoosmates(IV) By treatment of cis- or trans-[OsCl₄I₂]^2? with (SCN)₂ in dichloromethane the linkage isomers cis-[OsCl₄(NCS)₂]^2? ( 1 ), trans-[OsCl₄(NCS)(SCN)]^2? ( 2 ), cis-[OsCl₄(NCS)(SCN)]^2? ( 3 ) and trans-[OsCl₄(SCN)₂]^2? ( 4 ) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determinations on single crystals of cis-(Ph₄As)₂[OsCl₄(NCS)₂] (triclinic, space group P1 , a = 10.019(5), b = 11.702(5), c = 21.922(5) Å, α = 83.602(5)°, β = 85.718(5)°, γ = 73.300(5)°, Z = 2), trans-(Ph₄As)₂[OsCl₄ · (NCS)(SCN)] (monoclinic, space group P2₁/c, a = 18.025(5), b = 11.445(5), c = 23.437(5) Å, β = 94.208(5)°, Z = 4), cis-(Ph₄As)₂[OsCl₄(NCS)(SCN)] (triclinic, space group P1 , a = 10.579(5), b = 11.682(5), c = 22.557(5) Å, α = 81.073(5)°, β = 85.807(5)°, γ = 87.677(5)°, Z = 2) and trans-(Ph₄As)₂ · [OsCl₄(SCN)₂] (triclinic, space group P1 , a = 10.615(5), b = 11.691(5), c = 11.907(5) Å, α = 111.314(5)°, β = 96.718(5)°, γ = 91.446(5)°, Z = 1) reveal the complete ordering of the complex anions. The via N or S coordinated thiocyanate groups are located nearly direct above one of the cis-positioned Cl ligands with Os? N? C angles of 171.2° and 174.3° ( 1 ), 162.3° ( 2 ), 172° ( 3 ) and Os? S? C angles of 108.3° ( 2 ), 105.7° ( 3 ) and 105.5° ( 4 ). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salts of all four linkage isomers are assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are f_d(OsN) = 1.59 ( 1 ), 1.67 ( 2 ), 1.60 ( 3 ) and f_d(OsS) = 1.27 ( 2 ), 1.31 ( 3 ) and 1.32 mdyn Å^?1 ( 4 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved.     

Darstellung und Kristallstruktur von (n-Bu4N)3[Ir(NCS)(SCN)5]

Preparation and Crystal Structure of (n-Bu₄N)₃[Ir(NCS)(SCN)₅] The evaporated ethanolic extrakt of the reaction product of K₃[IrCl₆] and HNO₃, refluxed with an aqueous KSCN solution yields a mixture of the linkage isomers [Ir(NCS)_n(SCN)_6?-n]^3?, n = 0? 2, and small amounts of linkage isomeric chloropentarhodanoiridates(III), from which [Ir(NCS)(SCN)₅]^3? has been isolated by ion exchange chromatography on DEAE-cellulose. The X-Ray structure determination on a single crystal of (n-Bu₄N)₃[Ir(NCS)(SCN)₅] (monoclinic, space group P 2₁/a, a = 17.513(5), b = 32.607(5), c = 23.661(5) Å, β = 94.757(5)°, Z = 8) confirms the existance of a heteroleptic hexakis(thiocyanato(N)-thiocyanato(S))iridate(III) with an Ir? N distance of 2.03 Å and Ir? S bond lengths between 2.29 and 2.38 Å. The SCN groups with angles between 166 and 175° are nearly linear with Ir? S? C angles from 99.9 to 109.4°. The Ir? N? C angles of the two crystallographic independent anions are 166 and 174°.     

Comparative Thermogravimetric Studies of Poly(ether-ketone/sulfone) Imides and Their Parent Polymers: I. Poly(ether-ketone/sulfone) ethylimide

Thermogravimetry (TG) was employed to study the thermal degradation kinetics of poly(etherketone/sulfone)ethylimide (PEK-IE and PES-IE). The corresponding decomposition activation energies and reaction orders were obtained and the comparison was made with their parent polymerspoly(ether-ketone/sulfone) with Cardo group (PEK-C and PES-C). The results show that the degradation activation energies of PEK-IE and PES-IE were lower than that of PEK-C and PES-C; and two stages of the degradation process were found for all the four polymers. For PEK-IE and PES-IE, the activation energies in the first decomposition stage are much lower than that in the second stage and the two stages can be taken as slow induction and fast degradation, whereas for PEK-C and PES-C the activation energies in the first decomposition stage are larger than that in the second stage, and the two stages can both be taken as two fast degradation stages. The decomposition mechanism of the two stages was also speculated.This revised version was published online in November 2005 with corrections to the Cover Date.     

SYNTHESIS AND CHARACTERIZATION OF METAL COMPLEXES WITH AMPICILLIN

Abstract

The reaction, in water, of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with sodium ampicillinate at room temperature has allowed isolation of dimers with the following general formula [M(amp)Cl]₂ × nH₂O (n = 1.5?3.2). The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibilities and spectroscopic methods (IR, Raman, EPR and UV-Visible). A dinuclear structure based on octahedrally coordinated metal ions is proposed.     

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性     

Thermal Degradation of Poly(ε-caprolactone), Poly(L-lactic acid) and their Blends with Poly(3-hydroxy-butyrate) Studied by TGA/FT-IR Spectroscopy

Summary: The thermal degradation behavior of poly(ε-caprolactone) (PCL) and poly(L-lactic acid) (PLA) have been studied in different environment. It was found that these polymers undergo completely different degradation processes in nitrogen and oxygen atmosphere. In oxygen environment PCL and PLA mainly decompose to CO₂, CO, water and short-chain acids. In nitrogen atmosphere PCL releases 5-hexenioc acid, CO₂, CO and ε-caprolactone, whereas PLA decomposes to acetaldehyde, CO₂, CO and lactide. The polymer blends of poly(3-hydroxybutyrate) (PHB) with PCL and PLA decompose similar to the individual homopolymers with crotonic acid as the initial decomposition product of PHB.     

Energy relationship and the polarization of C_(60) cage in the endohedral complexes (X@C_(60))

In this paper, we carry out the calculation on the system (X@C60)(X=Li, Na, K, Kb, Cs; F, Cl, Br, I), where the position of X changes along 5 typical symmetry directions. For the calculation of quantum chemistry we use EHMO/ASED method, for the calculation of molecular mechanics we use Buckingham potential (exp-6-1) function, and for the calculation of thermo-chemical cycle we use individually isolating the processes such as the structure variation, charge transfer and charge distribution, and their interactions etc. The calculation results show that (1) In the region of radius r≈0.2 nm of the Ceo cage, the potential field is nearly spherical; (2) Except for Li and Na, the systems are the most stable with minimum energies at the center of C60 cage. For Li and Na, the systems are the most stable with minimum energies at r≈0.16 nm and r≈0.13 nm, respectively. In view of the interactive region of chemical bonds, the interactions between X and the C60 cage do not belong to the classical chemical bonds; (     

铜在3%NaCl溶液中腐蚀行为的光电化学研究

Cu以其优异的导电性、导热性和易加工性广泛用于工农业生产中．自然Cu的腐蚀和防腐成为人们很关注的问题．人们已经注意到，Cl-对Cu的腐蚀有影响，并进行过一些研究．但目前使用光电化学方法研究这一问题的文章尚不多见，特别是利用测量开路光电压及其瞬态波形这一现场的、无损的、灵敏的监测方法研究户对Cu电极腐蚀全过程的文章尚未见到．本文正是利用如上方法及XPS，AES方法，研究了Cl-对Cu电极腐蚀的全过程，取得了一些有意义的结果．1实验方法Cu电极用99．99％（质量分数）的Cu制成，面积约为39mm2；电极底部由Cu导线焊接引出，…     

On the morphological behavior of ABC miktoarm stars containing poly(cis 1,4-isoprene), poly(styrene), and poly(2-vinylpyridine)

Fundamental understanding of microphase separation in ABC miktoarm copolymers is vital to access a plethora of nonconventional morphologies. Miktoarm stars based on poly(cis 1,4-isoprene) (I), poly(styrene) (S), and poly(2-vinylpyridine) (V) are model systems, which allow systematic studies of the effects of composition, chemical microstructure, and temperature on the thermodynamics of microphase separation. Eleven ISV-x (I:S:V = 1:1:x, v:v:v) miktoarm copolymers were synthesized by anionic polymerization affording well-defined copolymers with a variable V arm. Equilibrium bulk morphologies of all samples, as evidenced by small-angle X-ray scattering, transmission electron microscopy (TEM), and self-consistent field theory, showed a systematic transition from lamellae (x ≈ 0–0.2) to [8.8.4] tiling (x ≈ 0.6–0.9) to cylinders in undulating lamellae (x ≈ 2–4) and, finally, to hexagonally packed core–shell cylinders (x ≈ 5–8). Chemical microstructure of the I arm [poly(cis 1,4-isoprene)] versus poly(3,4-isoprene) is shown to play important role in affecting morphological behavior. To reconcile differences between ISV-x star morphologies reported in the literature and those reported herein, even for the same composition, effects of the microstructure of I arm on the Flory–Huggins parameter between I and V arms were taken into account in a qualitative manner. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1491–1504