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1.
通过共沉淀法合成了发红色荧光的类水滑石材料,采用硅烷偶联剂对其进行了表面改性,并利用荧光光谱、红外光谱、X射线衍射(XRD)和扫描电子显微镜(SEM)等对其结构和性能进行了表征,探讨了表面改性对荧光类水滑石的影响.将改性荧光类水滑石与发射波长为384 nm的In Ga N芯片组合制成发光二极管,器件发出明亮的红光.研究结果表明,改性的发红色荧光的类水滑石是制作白光二极管可供选用的红色发光材料.  相似文献   

2.
高荧光性含锌类水滑石研究   总被引:1,自引:0,他引:1  
陈鸿  章文贡 《化学学报》2008,66(4):481-486
本研究将适量锌离子(II)取代镁铝水滑石中的镁离子(II), 以及将一定量的8-羟基喹啉(8-hydroxyquinoline)分散于镁铝水滑石层间的亲油性阴离子中, 使与其板层表面上的锌离子配位, 经共沉淀法, 合成、组装得到一类迄今未见报道的具高荧光性的类水滑石(Zn-HTLC)荧光材料. 采用荧光光谱、红外光谱、紫外光谱、X射线衍射和热分析等对其进行了表征. 研究表明, 这种类水滑石在紫外光下可发出强烈的蓝绿色荧光(501 nm), 荧光强度高达4.5×105 a.u., 说明锌离子(II)分散于类水滑石的氢氧化镁板层中, 可有效防止发光结构单元的荧光猝灭, 而且溶于层间阴离子中的配体与板层上的锌离子(II)配位所形成的特殊组装结构, 增强了发光中心的不对称性, 也是其具有高荧光性的可能原因. 热分析结果显示, 这种类水滑石耐热性强, 有望应用于各种功能性荧光材料.  相似文献   

3.
刁娟娟  王婷婷  李莉 《化学研究》2022,33(2):164-169
为克服现有量子点制备技术中存在的荧光量子产率较低及生物相容性差的问题,通过一步水热法合成一种高荧光量子产率的氮掺杂石墨烯量子点(N?GQDs),其荧光量子产率为94%.N?GQDs粒径在20~40 nm之间,最大激发波长为390 nm,发射波长为450 nm.N?GQDs呈现亮蓝色荧光,具有良好的光致发光作用.N?GQ...  相似文献   

4.
本文通过杂环胺类对二溴萘四酰亚胺的亲核反应,分别设计合成了8个未见报道的基于萘四酰亚胺母体的新型单取代或者双取代荧光染料.系统性光谱研究表明,胺类的推电子作用差异可以很好地调控其吸收和荧光波长,使之成为一类性能良好的可见或长波长荧光染料(最大吸收509—580 nm;最大发射565—638 nm;荧光量子效率0.21—0.54;Stokes位移36—77 nm).  相似文献   

5.
新型水溶性多色荧光碳点的制备及细胞成像研究   总被引:1,自引:0,他引:1  
以鸡蛋清和牛奶分别与葡萄糖进行水热反应,制备水溶性多色荧光碳点,通过膜和柱层析分离纯化,利用透射电子显微镜(TEM)、紫外吸收光谱(UV)、荧光光谱(FL)、红外光谱(FTIR)等技术对所制备碳纳米粒子的粒径大小、吸收光谱、发光性质、表面基团进行表征。将所制备的碳点与小鼠黑色素瘤细胞共孵育,进行细胞成像应用评价。结果表明:制备的两种水溶性荧光碳点平均粒径分别为2.5 nm和4.9 nm,可在紫外灯下发出明亮的荧光,紫外最大吸收波长为250 nm。基于鸡蛋清或牛奶与葡萄糖反应制备的多色荧光碳量子点具有良好水溶性,其荧光光谱最大发射波长分别在410 nm和400 nm处,同时在660~800 nm激发波长范围内具有上转换性质,且荧光发射光谱随着激发光波长的增加发生红移。红外光谱表明存在—COOH、—NH2和—OH基团。细胞成像结果表明,在405 nm或488 nm激光照射下,所制备的碳点在细胞内的荧光成像清晰可见,而且在碳点浓度小于2.5 mg/mL时,均表现出较低的细胞毒性。  相似文献   

6.
韩雍  汪慧  宋曦  雒雪丽 《分析测试学报》2018,37(12):1475-1479
以青柿子(Diospyros Kaki L. f)提取物作为碳源,通过水热法简易制备荧光碳点,并对其进行表征。结果显示所制备的碳点为类圆球颗粒,平均粒径为15. 39 nm。X射线衍射(XRD)表明该碳点为类石墨烯的无定形碳材料;光电子能谱(XPS)表明其构成元素较复杂,但以碳点为主的元素均有表达,且符合一般碳点材料的元素组成;该碳点表面含有羟基、羧基和氨基等活性基团;在350 nm处有紫外吸收,具有激发波长依赖性特点荧光,最大激发波长为355 nm,最大发射波长为445 nm;在355 nm激发波长下,其光谱发射在p H5. 0~11. 0范围内具有稳定的荧光。该碳点在365 nm紫外光照射下,表现出较强的蓝色荧光,对Fe3+具有较好的特异识别能力,可用于Fe3+的荧光检测。Fe3+浓度在0. 45~50μmol/L范围内与PM-CDs的荧光强度呈线性关系(r2=0. 923 4)。试验在碳点纯化方面存在局限,需进一步探讨生物质材料碳点纯化方式,提高目标分析物的识别位点保有量,获得高效检测目标。  相似文献   

7.
以中药材川木香原药为碳源,采用水热法一步合成了荧光碳量子点。通过水热法实验条件优化,获得制备荧光碳量子点的最佳实验参数,通过透射电镜(TEM)对荧光碳量子点进行形貌表征,通过X射线光电子能谱分仪(XPS)对荧光碳量子点进行元素组成分析,通过荧光光谱和紫外-可见吸收光谱对荧光碳量子点进行了光学性能研究。结果表明:川木香用量1.00 g,水热反应温度180℃,水热反应时间2.0 h时,制备得到的荧光碳量子点光学性能最佳。荧光碳量子点平均粒径为5 nm,主要含有C元素和O元素,最大激发波长为360 nm,对应的发射波长为420 nm,特征吸收峰为280 nm,量子产率为12.9%。  相似文献   

8.
以若丹明6G、水合肼和原甲酸三乙酯为原料合成了一种新型的若丹明类荧光探针化合物.采用IR、1H NMR、13C NMR、HRMS进行了结构表征,并对其荧光性能进行了研究,结果表明该探针对Hg2+有很好的识别作用.在水和甲醇体系中,探针分子溶液为无色;加入Hg2+,探针分子的最大吸收波长为510nm,荧光强度的最大发射波长为551 nm,探针溶液则呈现浅粉红色,而常见的其他金属离子对其干扰小.当pH小于3.80时,荧光强度显著增加,并显示明亮的粉红色;当pH大于3.80以后,荧光迅速减弱,溶液呈现无色,该探针也可以作为pH探针使用.  相似文献   

9.
CaWO4荧光体的微波热法合成和光致发光   总被引:4,自引:0,他引:4  
本文报道微波热法合成 Ca WO4荧光体 ,X射线粉末衍射分析确证为四方晶系 ,Ca WO4:Pb0 .0 1 荧光体最大激发波长 λex=2 66.0 nm,最大发射波长 λem=450 .0 nm,在 2 54nm激发下 ,色坐标 x=0 .1 66,y=0 .1 2 4 ,与市售同类荧光体比较 ,相对发光亮度 86% ,荧光体中心粒径 D50 为9.1 8μm,体积比表面 SV 为 81 93 1 / cm。  相似文献   

10.
TNT及RDX蒸气对基于芘氧敏感膜荧光猝灭的研究   总被引:1,自引:0,他引:1  
制备了以芘为敏感材料,聚苯乙烯(PS)以及聚氯乙烯(PVC)粉末为支持体系的两种荧光猝灭氧敏感膜.PS以及PVC氧敏感膜的最大激发波长分别为349 nm和355 nm,最大发射波长分别为399 nm和398 nm.分子氧对PS以及PVC氧敏感膜的荧光均有猝灭作用.同时,实验发现2,4,6-三硝基甲苯(TNT)和环三亚甲基三硝基胺(RDX)对这两种氧敏感膜的荧光也有一定的猝灭.  相似文献   

11.
共轭聚合物纳米粒子(CPNs)因其高荧光亮度、低毒性、表面易修饰的特性,近年来在生物材料和生物医药领域备受关注。本论文中我们设计、合成了一种新的pH 值响应共轭聚合物(PFPA),并通过纳米沉淀方法制备了其纳米粒子。动态光散射实验表明PFPA纳米粒子在水中分散性较好,其粒径约为8 nm。 PFPA纳米粒子的最大吸收峰为379 nm,其摩尔吸光系数为2.1×106 L·mol -1·cm -1;另外该纳米粒子的荧光最大发射峰为422 nm,其荧光量子产率为35%。PFPA纳米粒子在汞灯(100瓦)照射下表现出较好的光稳定性,另外MTT实验表明其具有较低的细胞毒性。该纳米粒子具有pH响应的光学特性,并可以用于活细胞成像。PFPA纳米粒子在癌症诊断、药物与基因传递等方面具有潜在的应用价值。  相似文献   

12.
The photoluminescence of Co-Al-layered double hydroxide   总被引:1,自引:0,他引:1  
We report a new optical behaviour of pure Co-Al-layered double hydroxide (LDH).It was found that the Co-Al-LDH sample could emit fluorescence without any fluorescent substances intercalated.Its excitation spectrum shows a maximum peak near the wavelength 370nm,the maximum emission peak appears at 430 nm and the photoluminescence colour of the Co-Al-LDH sample is blue.This new optical property will be expected to extend the potential applications of LDHs in optical materials field.  相似文献   

13.
A diamine containing heterocyclic pyridine and unsymmetrical carbazole substituents, 4‐(9‐ethyl‐3‐carbazole)‐2,6‐bis(4‐aminophenyl)pyridine ( CBAPP ), was prepared for use in the synthesis of poly(pyridine‐imide)s PI‐1–8 by direct polycondensation with dianhydrides in N,N‐dimethylacetamide (DMAc). The poly(pyridine‐imide)s derived from the diamine are highly soluble in solvents such as N‐Methyl‐2‐pyrrolidone (NMP) and DMAc at room temperature. Noncoplanar polyimide (PI‐1) showed excellent solubility, high transparency, and high‐performance mechanical properties. These polymers had relatively high glass transition temperatures and exhibited good thermal stability in both nitrogen (Td10 > 470 °C) and air (Td10 > 450 °C). The PI‐3~5 cannot form flexible and tough films due to the unsymmetrical carbazole moiety, rigid structure, and polar–polar interaction. However, through copolymerization technique these polymers (PI‐6~8) could be enhanced through the solubility, mechanical, and thermal properties. The optical properties included a strong orange fluorescence (540 nm) after protonation with acid. When the HCl concentration was increased, a new absorption band at approximately 350 nm appeared, and the intensity of the fluorescent peak at 380 nm observed in the neutral polymer solution decreased, along with the appearance of the new fluorescent peak at 540 nm. The poly(pyridine‐imide)s presented here showed only slight fluorescence quenching in the presence of methanol. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 405–412  相似文献   

14.
π‐Conjugated polymers (Poly1–Poly3) containing a 2,2′‐bipyridine (bpy) unit were subjected to coordination to nickel and copper dithiolate for the purpose of manipulating the photophysical properties. The absorption maximum peak of Poly1 [maximum wavelength (λmax) = 446 nm] redshifted by 36 nm upon the coordination of bpy to NiCl2, which produced Poly1–NiCl2. A further bathochromic shift was observed in the spectrum of Poly1–mntNi [mntNi = (maleonitrile dithiolate)nickel; λmax = 499 nm] bearing the dithiolate ligand, which stemmed from the extension of the conjugated system over the nickel dithiolate moiety through the bpy unit. An increase in the [Ni]/[bpy] ratio in Poly1–mntNi rendered the original maximum peak at 446 nm smaller and the lower energy charge‐transfer peak at 499 nm larger; the isosbestic points remained at 380 and 475 nm. The green fluorescence (λmax = 504 nm) emitted from Poly1 markedly diminished upon the coordination of nickel dithiolate because of the effective energy transfer. The absorption maximum peak of Poly1–mntNi in chloroform at 499 nm blueshifted to 471 nm when the volume ratio of the chloroform/N,N‐dimethylformamide solvent reached 10:90. The coordination of nickel dithiolate to Poly2 and Poly3 also brought about redshifts of the absorption maximum peaks of as much as 55 and 61 nm, respectively. The absorption maximum peak of Poly1–(phenyldithiolate)nickel(pdtNi) (λmax = 474 nm) redshifted by 28 nm in comparison with that of Poly1, whereas the magnitude of the shift of Poly1–bis(thiophenoxide)nickel(btpNi) bearing two thiophenoxide ligands was 20 nm. Poly1–mntCu with a tetrahedral copper center was also investigated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2631–2639, 2004  相似文献   

15.
A new carbazole functionalized Schiff base CBM was synthesized and characterized. CBM can selectively recognize Cu2+ via UV–vis and fluorescence signal among common biologically relevant metal ions. When Cu2+ was added to CBM, there was a significant enhancement at the maximum absorption wavelength of 393 nm and with a distinct blue shift. The maximum emission peak was significantly attenuated by a factor of about 15 times at 535 nm and the blue shift of emission wavelength was observed. When other metal ions were added, there was no remarkable change at the maximum absorption and emission peak. Under the illumination of 365 nm ultraviolet lamp, the color of the CBM solution changed from light blue to dark blue after the addition of Cu2+. The combination mechanism of CBM with Cu2+ was nicely explored by density functional theory studies. The probe CBM has good cell permeability, fluorescence electron microscopy experiments show that CBM can be used as a fluorescent probe to detect the presence or absence of Cu2+ in Hela cells. Furthermore, the probe CBM can also be used for the detection of copper ions in actual water samples.  相似文献   

16.
刘瑶  但飞君  鲁茜  张吉  兰海闯 《合成化学》2017,25(11):904-909
以邻氨基苯甲酸甲酯和4-二乙胺基水杨醛为原料,合成了一个新的香豆素喹啉衍生物3-{2-[8-(1H-苯并咪唑-2-基)喹啉-2-基]乙烯基}-7-二乙胺基香豆素(QMC),再与BF3·Et2O配位合成了硼氟配合物(BQMC),其结构经1H NMR和MS(ESI)表征。并对BQMC的光学性能进行了研究。结果表明:BQMC的最大吸收波长在二氧六环中为490 nm,在DMSO中为532 nm; BQMC的最大发射波长在正己烷中为618 nm,在DMSO中为679 nm,与配体QMC相比,最大吸收波长红移了近50 nm,最大发射波长红移了近100 nm, BQMC的Stokes位移值从115 nm增至183 nm。在固态下,BQMC在750~825 nm之间有较宽的荧光发射峰,具有较强荧光。  相似文献   

17.
A new quinoline‐based probe was designed that shows one‐photon ratiometric and two‐photon off–on changes upon detecting Cd2+. It exhibits fluorescence emission at 407 nm originating from quinoline groups in Tris‐HCl (25 mM , pH 7.40), H2O/EtOH (8:2, v/v). Coordination with Cd2+ causes quenching of the emission at 407 nm and simultaneously yields a remarkable redshift of the emission maximum to 500 nm with an isoemissive point at 439 nm owing to an intramolecular charge‐transfer mechanism. Thus, dual‐emission ratiometric measurement with a large redshift (Δλ=93 nm) and significant changes in the ratio (F500/F439) of the emission intensity (R/R0 up to 27) is established. Moreover, the sensor H2L displays excellent selectivity response, high sensitive fluorescence enhancement, and strong binding ability to Cd2+. Coordination properties of H2L towards Cd2+ were fully investigated by absorption/fluorescence spectroscopy, which indicated the formation of a 2:1 H2L/Cd2+ complex. All complexes were characterized by X‐ray crystallography, and TD‐DFT calculations were performed to understand the origin of optical selectivity shown by H2L. Two‐photon fluorescence microscopy experiments have demonstrated that H2L could be used in live cells for the detection of Cd2+.  相似文献   

18.
The synthesis and optical properties of polymers bearing the repeating unit of terfluorene and various organosilicon groups were investigated. Polymers with high molecular weight and good solubility could be obtained by Suzuki coupling polymerization from silylene‐containing fluorene‐based dibromo monomers and 9,9‐dihexylfluorene‐2,7‐bis(trimethyleneborate). From UV spectra of polymers bearing acyclic silylene bridge, the organosilicon units not only interrupted a π‐conjugation but also contributed to an electronic communication between connected fluorenes. The emission maximum wavelengths (ca. 400 nm) blue‐shifted when compared with that of polyfluorene (418 nm) and the fluorescence quantum yields were considerably high (>0.82) in the CHCl3 solution. On the other hand, rather broad emission was observed at 480 nm and the fluorescence quantum yield was quite low (0.004) in the solution‐state PL spectrum of tetraphenylsilole‐containing polymer. The polymer emitted visible green light in the spin‐coated film. The fluorescence peak intensity at 486 nm gradually decreased when the film was illuminated with the UV light of 359 nm in air. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4786–4794, 2007  相似文献   

19.
波浪形一维链状镉配合物的合成、结构及分子识别性能   总被引:1,自引:1,他引:0  
黄秋颖  林肖漪  王勇  朱永朝 《应用化学》2017,34(9):1093-1098
以四水合硝酸镉(Cd(NO_3)_2·4H_2O)与2-(邻溴)苯基-4,5-咪唑二羧酸(o-BrPhH_3IDC)和草酸铵通过水热反应,合成了一个波浪形一维链状配合物{[Cd(o-BrPhH_2IDC)_2(H_2O)]·H_2O}_n(1)。并通过元素分析、傅里叶变换红外光谱、热重分析和单晶X射线衍射等技术手段对配合物1进行了表征。结果表明,配合物1为正交晶系,Pbca空间群。配合物1在316 nm波长激发下,在356 nm处有最大的荧光发射峰。配合物1对小分子具有识别性能,乙腈使配合物荧光强度明显增强,甲醇、乙醇使配合物荧光强度明显减弱,而吡啶处理后的样品在356 nm附近的发射峰消失,显示对吡啶有识别作用。  相似文献   

20.
蒋治良  刘凤志  刘绍璞  卢欣 《分析化学》2003,31(11):1364-1368
在0.2mol/L HCl介质中,罗丹明S(RDS)分别在520nm和550nm处有一个吸收峰和荧光峰。当有Au(Ⅲ)存在时,Au(Ⅲ)与Cl^-形成AuCl4^-,AuCl^-与RDS^ 借助于静电引力形成疏水性的AuCl4-RDS缔合物分子。AuCl4-RDS分子间存在较强的分子间作用力和疏水作用力而生成(AuCl4-RDS)。缔合纳米微粒,粒径为45nm。在360nm产生瑞利散射峰,在600nm产生共振散射峰。由于纳米微粒形成后,只有裹露在(AuCl4-RDS)n纳米微粒界面的RDS荧光分子才能吸收激发光子跃迁到激发态,进而返回基态产生荧光。而体相的RDS荧光分子无法与激发光作用产生荧光,即受激RDS分子数大为降低,故550nm荧光峰和520nm吸收峰的降低。当缔合纳米微粒体系加入乙醇后,体系的红紫色和共振散射峰消失,吸收峰和荧光峰恢复,由于乙醇致使(AuCl4-RDS)。纳米微粒分解为AuCl4-RDS分子。结果表明:红紫色(AuCl4-RDS)n纳米粒子的形成是其共振散射增强、荧光猝灭和产生共振散射峰的根本原因。  相似文献   

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