三苯胺多枝化合物的合成及其荧光性质

采用Heck反应合成了2个三苯胺多枝化合物N,N,N-三{5-(4-叔丁基苯基)-1,3,4-噁二唑-2-苯乙烯基-4-苯基}胺(化合物1)和N,N,N-三[4-{2-(3,5-二-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2-]苯基}-1-乙烯基}苯基}胺(化合物2),并测定了它们的吸收光谱、单光子荧光光谱和双光子荧光光谱.化合物1和2在二氯甲烷溶液中单光子荧光发射峰分别位在536和487nm.在锁模Nd:YAG激光器800nm激光照射下,化合物1和2发射出很强的双光子上转换荧光,其最大波长分别在541和518nm.     

[1,3,4]-噁二唑衍生物的固相合成及其线性、非线性光谱性质

用固相法合成了2个噁二唑衍生物类有机化合物:5-(4-叔丁基苯基)-[1,3,4]噁二唑-2-苯乙烯基-4-苯基-二苯胺 (化合物1)与9-乙基-3,6-双{5-(4-叔丁基苯基)-[1,3,4] 噁二唑-2-苯乙烯基}-咔唑 (化合物2),并测定了它们的吸收光谱、单光子荧光光谱和双光子荧光光谱.化合物1和2在二氯甲烷溶液中单光子荧光发射峰分别位于519和476nm.在锁模Nd∶YAG激光器800nm激光照射下,化合物1和2发射出很强的双光子上转换荧光,其最大波长分别在520和485nm.     

用飞秒Ti：sapphire激光测定对称型化合物的双光子吸收和上转换荧光

用800nm波长的飞秒Ti:sapphire激光测定了2个对称型噁二唑衍生物2,5-二[4-(2-N,N-二苯氨基苯乙烯基)苯基]-1,3,4-噁二唑(PASPO)与2,5-二[4-{2-N,N-二(4-溴代苯)氨基苯乙烯基]苯基}-1,3,4-噁二唑(BrPASPO)的双光子吸收和双光子激发荧光光谱,其飞秒双光子吸收截面为20.6和9.91GM,双光子泵浦上转换荧光最大波长分别在535和545nm.测定了紫外吸收、荧光光谱,研究了化合物在不同溶剂中的溶致变色效应.化合物PASPO和Br-PASPO在二氯甲烷溶液中的吸收峰分别位于412和403nm,荧光发射峰分别位于511和495nm,荧光量子产率分别为0.73和0.70.     

新型双光子聚合引发剂的合成和非线性光学性质的研究

合成了两种新的双光子聚合引发剂反式-二苯基-{{4-[2-(4-吡咯基-1-苯基)-乙烯基]-苯基}胺(简称DPVPA)和反式-9-{4-[2-(4-吡咯基-1-苯基)-乙烯基]-苯基]-9-氢咔唑(简称PPVPA).用1H NMR谱和元素分析进行了表征.测试了紫外吸收光谱、单光子荧光光谱、单光子荧光寿命和双光子荧光光谱.在760 nm的飞秒脉冲激光激发下,DPVPA和PPVPA均发出较强的上转换荧光,荧光峰分别位于468和452 nm.以DPVPA做引发剂,加入丙烯酸酯型齐聚物(CN120C80),用DATACHROOM-5000纳秒激光器辐射出600nm的激光做光源,实现了双光子聚合反应,并定性地解释了其聚合机理.     

三苯胺衍生物的合成

三苯胺衍生物是构建光电功能材料的关键中间体，采用条件温和、产率较高的合成路线，对三苯胺母核进行官能团化修饰，制备了三苯胺单酰基、双酰基、三酰基及二溴代、三溴代衍生物及化合物双{5-（4-叔丁基苯基）-[1，3，4]-嗯二唑-2-苯乙烯基-4-苯基}-苯胺，并讨论了三苯胺Vilsmeier-Haack甲酰反应制备方法。     

一种新型含卟啉的环金属化有机配体的设计、合成与性质

采用Aldol、Adler缩合、Michael加成、Vils-meier和Knoevenagel等反应合成一种新型的D-π-A型的含C∧N∧N结构的环金属化有机配体：反式-4-[2-（5,10,15,20-四苯基卟啉基）乙烯基]-N-{4-[（2-苯基-6-吡啶基）吡啶]苯甲基}吡啶溴盐（简写为TPPB）。用核磁共振氢谱、碳谱和电喷雾质谱等手段对其结构进行了表征,初步研究了该化合物的紫外-可见光谱、荧光光谱、电化学和热稳定性。结果表明目标化合物有较好的溶解性和荧光性质,为寻找新的发光材料进行了有益的探索。     

1,2,4,5-四取代苯的合成与荧光性质

通过Wittig-Horner反应合成了两个四取代苯:1,2,4,5-四(4-N,N-二苯氨基苯乙烯基)苯 (TDASB)和1,2,4,5-四[4-N,N-二(4-溴苯基)氨基苯乙烯基]苯(TDBSB).目标化合物结构经过红外光谱、核磁共振谱、质谱和熔点确证,测定了它们在不同溶剂中的紫外光谱和荧光光谱.TDASB 和TDBSB在二氯甲烷中的最大吸收峰分别位于400和396nm,最大发射峰分别为493和491nm,荧光寿命分别为1.7022、3.633和1.2810、4.8473ns,讨论了Stokes位移与溶剂极性的关系.     

一种共轭有机杂环分子的双光子吸收与电化学性质

实验研究了一种新的共轭杂环化合物9-乙基-3-{5-(4-叔丁基苯基)-[1,3,4]-噁二唑-2-苯乙烯基}-咔唑(VBPOEC)的双光子吸收性质和电化学性质.双光子吸收截面采用非线性透过率法测定,双光子最大吸收波长位于800nm,吸收截面为1350GM.采用紫外光谱的边带吸收法得到带隙为2.77eV,用循环伏安法对其电化学性质进行了初步研究,氧化电位为1.059V,其HOMO能级为-5.80eV,其LUMO轨道能级为-3.03eV.研究了光学、电化学性质与分子电子结构的关系.     

茚修饰的蒽类荧光材料的合成及性能

合成了一种茚修饰的蒽类衍生物(INAN)——9,10-二[4-(1,1-二甲基-3-苯基-1H-茚)苯基]蒽,经核磁共振氢谱、碳谱以及高分辨质谱等手段表征了其结构。应用紫外-可见吸收光谱、荧光光谱、循环伏安法和热重分析研究了其光物理、电化学和热稳定性能,计算了其HOMO、LUMO能级和电化学能隙。并将其与工业应用的9,10-二(4-(2,2-二苯乙烯基)苯)蒽进行性能比对,发现该材料的荧光发生蓝移,同时在热稳定性和发光量子产率上均有改善。该类化合物可作为高效的蓝光荧光材料,应用于有机电致发光材料及生物显像等领域。     

一种基于D-π-A型芴衍生物的合成、核磁共振谱及光谱性能研究

合成了一种具有D-π-A结构特征的新型芴衍生物:2-(2,4-二氟苯基)-7-(4-甲氧基苯基)-9,9-二辛基芴(1)。通过元素分析、红外光谱(IR)以及全面的一维核磁共振氢谱(1 H NMR)、碳谱(13 C{1 H}NMR)、氟谱(19F{1 H}NMR)对其结构进行了全面表征。通过优化反应物的投料顺序,得到较为合理的合成方法。详细分析了核磁共振谱谱线特征。利用紫外-可见吸收和荧光光谱研究了化合物的发光性能。结果表明,在CH2Cl2溶液中,化合物1在300~330nm波段有吸收峰,归属于π-π*跃迁;其光学带隙Eg为3.39eV,发射峰值位于383nm,并且具有强烈的深蓝色荧光发射(激发波长为310nm),在CH2Cl2溶液中量子效率达到0.70。此外,化合物1的吸收和发射光谱具有溶剂极性依耐性。     

Synthesis and Characterization of Double-layer Quantum-Dots-Tagged Microspheres

Quantum-dots-tagged poly (styrene-acrylamide-acrylic acid) microspheres (QDsAAMs) were synthesized and modified with hydrazine hydrate through hydrazinolysis. Azidocarbonyl groups, which can be rapidly coupled with proteins under mild conditions, were introduced onto the surface of QDsAAM using azido reaction. Bovine serum albumin (BSA) was selected as model protein to be covalently immobilized on the azidocarbonyl QDsAAM. Instruments such as fluorescence microscope, optical microscope, confocal laser scanning microscope, UV–visible spectrometer, Fourier transform infrared spectrometer, size analyzer, and fluorescence spectrophotometer were used to characterize QDsAAM. Results showed that QDsAAM had a regular double-layer spherical shape and an average diameter of 11.2  $mu$m. It also displayed high fluorescence intensity ( ${lambda}_{{rm ex}}/{lambda}_{{rm em}} = hbox{250}$ nm/370 nm), which showed linearity with concentrations ranging from $hbox{3.0} timeshbox{10}^{-3}$ to $hbox{90.0} times hbox{10}^{-3} hbox{g}{cdot}hbox{L}^{-1}$. In addition, external factors such as pH and ionic strength exerted little influence on fluorescent characteristic. BSA immobilization indicated that QDsAAM with azidocarbonyl groups could be covalently coupled with BSA at the rate of $hbox{40} times hbox{10}^{-3}$ g/g (BSA/QDsAAM), while fluorescence linearity correlation was also found. This functional azidocarbonyl QDsAAM with sensitive fluorescence and active azidocarbonyl groups could be used as a promising fluorescent probe for quantitative detection, protein immobilization, and early rapid clinical diagnostics.      

Crystalline perfection and optical properties of rapid grown KH2PO4 crystal with chromate additive

Potassium dihydrogen phosphate (KDP) crystals were grown in the presence of a series of chromate (CrO $_{4}^{2-}$ ) additive concentrations via rapid growth method. CrO $_{4}^{2-}$ made KDP crystals were coloured by yellow-green, suggesting CrO $_{4}^{2-}$ had entered into the crystal lattice. The elemental analysis indicated that Cr element in KDP crystal was at ppm level. High resolution X-ray diffraction data revealed that the crystalline perfection of these as-grown KDP crystals was destroyed after CrO $_{4}^{2-}$ entered into crystal lattice, embedded in the full width at half maximum was broadened and satellite peaks appeared. Additionally, the extinction ratio was decreased with rise of CrO $_{4}^{2-}$ concentration. CrO $_{4}^{2-}$ introduced two absorption peaks centred at 360 and 280 nm and enhanced the intrinsic absorption near 220 nm, which were at the same band positions compared with the CrO $_{4}^{2-}$ or HCrO $_{4}^{-}$ transmittance spectra. Additionally, CrO $_{4}^{2-}$ could increase the size of light scattering, which was attributed to the point defects and microscopic defects by the replacement by CrO $_{4}^{2-}$ at PO $_{4}^{3-}$ position.     

Effect of CTAB coating on structural,magnetic and peroxidase mimic activity of ferric oxide nanoparticles

In the present work, pristine and cetyl trimethyl ammonium bromide (CTAB)-coated ferric oxide nanoparticles \((\hbox {CTAB@Fe}_{2}\hbox {O}_{3} \hbox { NPs})\) were synthesized and studied as enzyme mimics. The w/w ratio of \(\hbox {Fe}_{2}\hbox {O}_{3}\) to CTAB was varied as 1:1 and 1:2. Transmission electron microscopic analysis revealed that pristine NPs had an average size of 50 nm, whereas the presence of CTAB resulted in the formation of nanorods with length of 130 nm. BET studies confirmed enhancement of surface area on CTAB coating, which was maximum for w/w ratio 1:1. The synthesized pristine NPs and CTAB-coated NPs were evaluated for their peroxidase mimic activity using o-dianisidine dihydrochloride as substrate. Optimum pH, temperature, substrate and NPs concentration for the reaction were 1, \(25^{\circ }{\mathrm{C}}\), \(0.16~\hbox {mg}~\hbox {ml}^{-1}\) and \(1~\hbox {mg}~\hbox {ml}^{-1}\), respectively. Peroxidase mimic activity of \(\hbox {CTAB@Fe}_{2}\hbox {O}_{3}\hbox { NPs}\) (w/w 1:1) was higher than that of pristine NPs. However, further increase in CTAB coating (w/w 1:2) resulted in lowering of peroxidase mimic activity. Kinetic analysis was carried out at optimized conditions; maximum velocity (\(V_{\mathrm{max}})\) and Michaelis constant (\(K_{\mathrm{m}})\) value of \(\hbox {CTAB@Fe}_{2}\hbox {O}_{3}\hbox { NPs}\) at 1:1 w/w ratio were 7.69 mM and \(1.12~\upmu \hbox {mol}~\hbox {s}^{-1}\), respectively.     

Photopyroelectric Characterization of Magnetic Nanofluids. Influence of Type and Size of Nanoparticles on the Thermal Parameters

The influence of type and size of nanoparticles on the thermal parameters of some magnetic nanofluids is investigated. Two types of carrier liquids (transformer oil and polypropylene glycol) were combined with two types of iron based magnetic nanoparticles (\(\hbox {Fe}_{3}\hbox {O}_{4}\) and \(\hbox {MnFe}_{2}\hbox {O}_{4})\). Different sizes (10 nm–80 nm) and shapes (spherical, octahedral or cubic) of nanoparticles were obtained depending on the oleic acid/oleylamine molar ratio, which drastically influences the nanocrystals growth rate. This influence is due to the different binding ability of the two stabilizers onto crystal facets. The average size of nanoparticles was 10 nm, 35 nm and 50 nm for \(\hbox {Fe}_{3}\hbox {O}_{4}\) and 10 nm, 20 nm and 80 nm for \(\hbox {MnFe}_{2}\hbox {O}_{4}\) at a concentration of 50 mg\({\cdot }\)ml\(^{-1}\) in all cases. The results obtained by PPE technique indicate that, at this concentration, the presence of the nanoparticles reduces the value of the thermal parameters of pure carrier liquids and both thermal diffusivity and effusivity decrease with increasing nanoparticles size, independently on the carrier liquid. The influence of the nanoparticles size is more pronounced for the thermal effusivity (relative change 24 %) compared with thermal diffusivity (relative change 7 %).     

Effects of electrolyte concentration and current density on the properties of electro-deposited NiFeW alloy coatings

NiWP alloy coatings were prepared by electrodeposition, and the effects of ferrous chloride (\(\hbox {FeCl}_{2})\), sodium tungstate (\(\hbox {Na}_{2}\hbox {WO}_{4})\) and current density (\(D_{\mathrm{K}}\)) on the properties of the coatings were studied. The results show that upon increasing the concentration of \(\hbox {FeCl}_{2}\), initially the Fe content of the coating increased and then tended to be stable; the deposition rate and microhardness of coating decreased when the cathodic current efficiency (\(\eta \)) initially increased and then decreased; and for a \(\hbox {FeCl}_{2}\) concentration of \(3.6\, \hbox {g\,l}^{-1}\), the cathodic current efficiency reached its maximum of 74.23%. Upon increasing the concentration of \(\hbox {Na}_{2}\hbox {WO}_{4}\), the W content and microhardness of the coatings increased; the deposition rate and the cathode current efficiency initially increased and then decreased. The cathodic current efficiency reached the maximum value of 70.33% with a \(\hbox {Na}_{2}\hbox {WO}_{4}\) concentration of 50 g \(\hbox {l}^{-1}\), whereas the deposition rate is maximum at 8.67 \(\upmu \hbox {m}\,\hbox {h}^{-1}\) with a \(\hbox {Na}_{2}\hbox {WO}_{4}\) concentration of \(40\, \hbox {g\,l}^{-1}\). Upon increasing the \(D_{\mathrm{K}}\), the deposition rate, microhardness, Fe and W content of the coatings increased, the cathodic current efficiency increases first increased and then decreased. When \(D_{\mathrm{K}}\) was 4 A dm\(^{-2}\), the current efficiency reached the maximum of 73.64%.     

Magnetoresistance and Magnetic Anisotropy Properties of Strain-Induced Co/Ag Multilayer Films

We report on the magnetoresistance (MR) properties of [Co(tCo)/Ag 1.5 nm]$_{20}$ multilayer and alloy films grown with the pulse electrochemical deposition on a polyamide substrate (1 cm$^{2}$ ). The induced uniaxial magnetic anisotropy was observed due to the effect of strain in all the multilayer films. The multilayer [Co 1.5 nm/Ag 1.5 nm]$_{20}$ showed a minimum hysteresis loss. The maximum MR ratio for Co/Ag was 9.2% at 1 kOe. A remarkable difference of magnetic field dependence of the magnetoresistance ratio was observed, corresponding to the orientation of magnetization curves.      

Effect of annealing treatment on optical properties and microstructural variation of $$\hbox {WO}_{3}/\hbox {Ag}/\hbox {WO}_{3}$$ multilayer nano-films

Structural and optical properties of \(\text {WO}_{3}/\text {Ag}/\text {WO}_{3}\) nano-multilayer composites were investigated for heat mirror applications. \(\text {WO}_{3}/\text {Ag}/\text {WO}_{3}\) thin films were fabricated through a physical vapour deposition method by using electron-beam evaporation at the vacuum chamber at 10\(^{-5}\) Torr. \(\text {WO}_{3}\) nano-layer was fabricated at 40 nm. Annealing treatment was carried out at 100, 200, 300 and 400\(^{\circ }\)C for 1 h after the deposition of first layer of \(\text {WO}_{3}\) on the glass. On \(\text {WO}_{3}\) film, Ag nano-layers with 10, 12 or 14 nm thickness were deposited. Individual layers morphology was investigated using atomic force microscopy (AFM) and deduced that a smoother layer can be achieved after the annealing at 300\(^{\circ }\)C. Ellipsometry analysis was executed to determine both layers, Ag film thickness and inter-diffusion between the \(\text {WO}_{3}\)–Ag–\(\text {WO}_{3}\) layers. It was inferred that there was almost no interfering among the \(\text {WO}_{3}\)–\(\text {WO}_{3 }\) layers in the samples with 12 and 14 nm Ag thickness; while silver was deposited on the annealed \(\text {WO}_{3}\) layer at 300\(^{\circ }\)C. UV–visible spectrophotometer showed that the annealing treatment of the first \(\text {WO}_{3}\) layer enhanced the transparency of films in the visible region. The innovations of the present study have been based on the annealing of the films and finding an optimum thickness for the Ag film at 12–14 nm. Heat mirrors efficiency was assessed according to the principle of their optical behaviour and optimum performance obtained for 14 nm of Ag film, deposited on annealed tungsten oxide at 300\(^{\circ }\)C.     

Syntheses and dielectric properties of perovskite ceramic system PFW0.8−x·PMN0.2·PFNx

(Fe system perovskite powders (phase purity >99%) were prepared via B-site precursor routes. Lattice parameter changes were analyzed in terms of B-site cation stoichiometries and sizes. Weak-field radio-frequency dielectric characteristics were investigated to verify the effect of composition modification on Curie temperatures and maximum dielectric constants. Unusual relaxation behaviors of frequency dispersion in the dielectric constant spectra at paraelectric region were observed.     

Magnetic Properties of Nanocrystalline Nickel–Cobalt Ferrites (\mathrm{Ni}_{1/2}{\mathrm{{Co}}}_{1/2}{\mathrm{{Fe}}}_{2}{\mathrm{O}}_{4})

In this study, the nanocrystalline nickel–cobalt ferrites $(\mathrm{Ni}_{1/2}\mathrm{Co}_{1/2}\mathrm{Fe}_{2}\mathrm{O}_{4})$ were prepared via the citrate route method at $27\,^{\circ }\mathrm{C}$ . The samples were calcined at $300\,^{\circ }\mathrm{C}$ for 3 h. The crystalline structure and the single-phase formations were confirmed by X-ray diffraction (XRD) measurements. Prepared materials showed the cubic spinel structure with m3m symmetry and Fd3m space group. The analyses of XRD patterns were carried out using POWD software. It gave an estimation of lattice constant “ $a$ ” of 8.3584 Å, which was in good agreement with the results reported in JCPDS file no. 742081. The crystal size of the prepared materials calculated by Scherer’s formula was 27.6 nm and the electrical conductivity was around $10^{-5}~\mathrm{S}\,\cdot \, \mathrm{m}^{-1}$ . The permeability component variations with frequency were realized. The magnetic properties of the prepared materials were analyzed by a vibrating sample magnetometer (VSM). It showed a saturation magnetization of $27.26\,\mathrm{emu} \cdot \mathrm{m}^{-1}$ and the behavior of a hard magnet.