基于非线性方法的食品着色剂光谱的研究

食品着色剂大多含有对人体有害的物质,需要严格控制其用量。利用吸收光谱法和荧光光谱法测量出了五种常见的食品着色剂亮蓝、胭脂红、苋菜红、柠檬黄、日落黄的吸收光谱和荧光光谱。当溶液浓度较小时,对五种着色剂进行了光谱强度和溶液浓度的线性拟合,拟合得到的线性区间非常小,利用线性关系对溶液浓度进行定标存在较大的局限性,在高浓度时必须进行稀释。利用非线性拟合的方法在较大的浓度范围内探究了五种着色剂的光谱强度与溶液浓度的关系,在此基础上,分别用线性定标法(先稀释)和非线性定标法对一种饮料中的着色剂含量进行了测量,并对两种方法的测量结果进行了比较,为扩大溶液的定标范围提供了一种参考方法和实验依据。     

CEL溶液中二磺酸基二邻苯二甲酰亚胺甲基酞菁锌的电子吸收和荧光光谱

两亲性金属酞菁配合物二磺酸基二邻苯二甲酰亚胺甲基酞菁锌（ＺｎＰｃＳ２Ｐ２）能有效选择地滞留在组织中,是一种新型的光动力治疗肿瘤的光敏剂。有关酞菁化合物治疗肿瘤的机制目前还不清楚,而对ＣＥＬ溶液中该光敏剂状态的研究对阐明其机制有重要意义,本文对不同浓度ＣＥＬ溶液中的二磺酸基二邻苯二甲酰胺甲基酞菁锌的吸收光谱和荧光光谱进行了研究,探讨了它在溶液中的聚集状态,通过分析确定其聚集态为二聚体,并获得其平衡常数和单体的摩尔吸光系数。     

水溶性酞菁类光敏剂的合成及其光谱性质研究

以3-硝基邻苯二甲腈与3-巯基-1-丙磺酸钠为原料,在醋酸盐存在下通过四环化合成了三种带四个3-磺基丙基磺酰基的水溶性酞菁。利用紫外-可见吸收光谱,荧光光谱等对其光谱性质进行了测量,并计算了其荧光量子产率和单线态氧量子产率。引入吸电子基团所合成的水溶性酞菁与ZnPc相比,其荧光发射光谱的形状并未改变,但其最大荧光发射波长均发生10 nm以上的红移。三种水溶性酞菁中锌酞菁的荧光量子产率最高,铜酞菁的荧光量子产率最低;它们在水溶液中的荧光呈双指数衰减,这可归结为激发态质子化或去质子化的结果。单线态氧量子产率锌酞菁最大,空心酞菁次之,铜酞菁最小。光谱分析结果表明,合成的锌酞菁和空心酞菁具有高的单线态氧量子产率和高的光稳定性,有望用作光动力治疗和光免疫治疗的光敏剂。     

全氟取代的钛酞菁衍生物的非线性光学和光限幅性能研究

制备和研究了全氟取代的钛酞菁F_(16)PcTiO及其轴向取代衍生物F_(16)PcTiO_2PhCHO的线性和非线性光学(含光限幅)性能。与F_(16)PcTiO相比,轴向取代的钛酞菁F_(16)PcTiO_2PhCHO的Q带最大峰红移了7 nm。Z-扫描实验表明,无论在甲苯溶液中还是在氯仿溶液中,F_(16)PcTiO都展现出比F_(16)PcTiO_2PhCHO更大的非线性吸收系数和低的饱和能量密度。F_(16)PcTiO_2PhCHO在氯仿溶液中的光限幅性能要明显优于其在甲苯溶液中的光限幅性能。与高度可溶的四叔丁基取代的钛酞菁(tBu_4 PcTiO和tBu_4 PcTiO_2 PhCHO)相比,十六氟取代的钛酞菁化合物具有较强的由酞菁环间范德华力驱动的分子间相互作用,这种相互作用导致材料在有机溶剂中的溶解度降低和非线性性能(含光限幅)性能下降。     

基于共振瑞利散射法的人血清蛋白浓度的研究

文章针对人标准血清总蛋白浓度的定量测定, 建立了以四羧基金属酞菁锌为光谱探针检测蛋白质的共振光散射的新方法。该方法的实质是将人标准血清总蛋白和酞菁锌溶液混合, 当光源照射到样品池中的混合液时, 将激发出强烈的共振瑞利散射荧光信号, 根据信号强度的强弱, 计算血清蛋白浓度的大小。自行设计的测试装置采用了薄壁试管的样品皿, 减小了激光光波穿过溶液时的光程, 可得到更强的探测信号。测试结果表明: 根据数字示波器显示的探测器信号, 可得出电压的峰峰值, 体现了荧光的大小, 从而可以进一步计算出血清蛋白的浓度。     

温度对萘酞菁LB膜光学特性的影响

本文采用线性吸收谱研究了温度对两种不同结构的萘酞菁分子LB膜光学特性的影响。研究发现,加热可以使它们在LB膜中的聚集体离解,四叔丁基萘酞菁锌的LB膜结构较三叔丁基氰基萘酞菁的LB膜要稳定。     

两种取代酞菁锌的合成及其光物理性质的研究

文章采用熔融法合成了两种通过不同基团连接的邻苯二甲酰亚胺取代酞菁锌,四-β-(邻苯二甲酰亚胺丁氧基)酞菁锌(1)和四-β-(邻苯二甲酰亚胺甲基)酞菁锌(2)。比较了两种不同的取代基连接方式对酞菁的电子吸收光谱、荧光光谱及荧光量子产率和产生单线态氧的能力的影响。结果表明：与无取代酞菁锌相比,四-β-(邻苯二甲酰亚胺丁氧基)酞菁锌(1)的电子光谱和荧光光谱的红移程度均大于四-β-(邻苯二甲酰亚胺甲基)酞菁锌(2)。由于1的给电子能力比2强,两种锌酞菁的荧光量子产率(Ф_F)的大小顺序为：1＞2,产生1O₂的能力的大小顺序为：2＞1。     

三-α-(2,4-二甲基-3-戊氧基)溴硼亚酞菁的三阶非线性光学性质研究

应用Z扫描技术，在波长为532nm、脉宽为8ns条件下，对一种新型亚酞菁配合物三-α-(2,4-二甲基-3-戊氧基)溴硼亚酞菁的三阶非线性光学特性进行了研究，结果发现，该新化合物有较强的反饱和吸收(β=3.7×10^-10 m/W)效应和非线性自聚焦折射效应(n₂=7.2×10^-11esu)，其三阶非线性极化率χ⁽³⁾=1.1×10^-11esu.分析了溴硼亚酞菁配合物特殊的锥形分子结构和重原子溴的轴向配位等因素对其三阶非线性光学性质的重要影响. 关键词： 亚酞菁 Z扫描 三阶光学非线性     

单异硫氰基3：1不对称酞菁锌的光谱性质研究

测定了三种含异硫氰基3：1不对称酞菁锌配合物（RO）6（NCS）PcZn（Ⅱ）（R=n-C4 H9；n-C5 H11;n-C10H21）在五种有机溶剂中的电子吸收光谱，研究了取代基和溶剂对吸收光谱的影响和规律。同时测定它们在有机溶剂中的荧光发射光谱，研究了外部取代基、溶剂和浓度对最大发射波长及荧光强度的影响规律，发现此类配合物具有特定的荧光效应，有望成为光动力诊断和治疗的有效光敏剂。     

稀土夹心双萘酞菁LB膜的非线性光学特性研究

研究了中心对称稀土夹心双萘酞菁化合物LB膜的光谱及其二阶非线性光学特性.双(四叔丁基萘酞菁)铒能制成很好的LB膜,不论在稀溶液中还是在LB膜中均主要以单体的形式存在,分子具有较大的超极化率β.由于分子为中心对称结构,所以它们的二次谐波产生机制不同于不对称萘酞菁化合物,研究证明它的二阶非线性光学特性起源于电四极子模型,其LB膜的有效二阶非线性极化率χ(2)为1.1×10-8 esu.     

Photophysical and nonlinear optical properties of zincphthalocyanines with peripheral substitutions

Photophysical and nonlinear optical properties of zinc phthalocyanines (ZnPc) bearing peripheral phenoxy substituents containing different functionalized groups were studied. Fluorescence spectra corresponding to the optical transition S₁ → S₀ are found to be appeared at 684 or 686.4 nm. Z-scan technique reveals large nonlinearities, where the absorptive and refractive effects are separately evaluated. Saturation absorption of ZnPc-1 was observed at 632.8 nm, with a very large nonlinear absorption coefficient β = −1.36 × 10⁻² cm/W. However a strong nonlinear refractive effect was found in all ZnPcs (1-4). Transmitted versus incident irradiance measurements carried out on ZnPc-1 and ZnPc-2, showed a very clear optical limiting behavior with irradiance thresholds around be 44 W/cm² and 90 W/cm² respectively.     

某些金属酞菁配合物的单体电子吸收光谱和荧光光谱

研究了某些金属酞菁配合物在单体状态下的电子吸收光谱和荧光光谱,并探讨了溶剂、中心离子和取代基的影响效应。     

Optical limiting properties of trimeric metallo-phthalocyanines/polymer composite films

The nonlinear absorption and optical limiting properties of two trimeric metallo-phthalocyanines namely, 2,4,6-tris[2-oxa-9,10,16,17,23,24-hexa(hexylthio) phthalocyaninato M(II)]-s-triazine (M=Zn for compound ZnPc and Cu for compound CuPc) doped polyvinyl chloride (PVC) thin film in the nanosecond regime were investigated by using the open-aperture Z-scan technique. The measurements were performed using 4 ns pulses generated from a frequency-doubled Nd:YAG laser at 532 nm wavelength. OL parameters of the ratio of the excited state to ground state absorption cross-sections κ, the effective nonlinear absorption coefficient β_eff, the linear absorption coefficient α₀ and the saturation density or energy density F_sat values were determined. The results show that MPc/PVC composite displays much larger nonlinear absorption coefficient and lower saturable fluence for optical limiting when compared to the same Pc molecules in solution. The results indicated that both compounds exhibited good OL performances. ZnPc shows slightly better OL parameters than that of CuPc.     

4-硝基-4′-氨基偶氮苯的光学性质研究

采用紫外可见吸收和二次谐波产生技术研究了“推-拉”型偶氮苯分子Langmuir-Blodgett(LB)膜的光谱和二阶非线性光学特性.4-硝基-4′-氨基偶氮苯(NAA)分子能制成很好的LB多层膜,在稀溶液中以单体的反式异构体形式存在,在膜中主要以J-聚集体的形式存在,LB膜的紫外可见吸收谱的吸收峰较之溶液的发生了52 nm的红移.NAALB膜的二阶非线性极化率χ(2)为19.59×10－8 esu,一阶超极化率β值较大,约为1.974×10－29 esu.其光学二阶非线性起源于电偶极子机制.     

Intense laser effects on the optical properties of asymmetric GaAs double quantum dots under applied electric field

We investigated the combined effects of a non-resonant intense laser field and a static electric field on the electronic structure and the nonlinear optical properties (absorption, optical rectification) of a GaAs asymmetric double quantum dot under a strong probe field excitation. The calculations were performed within the compact density-matrix formalism under steady state conditions using the effective mass approximation. Our results show that: (i) the electronic structure and optical properties are sensitive to the dressed potential; (ii) under applied electric fields, an increase of the laser intensity induces a redshift of the optical absorption and rectification spectra; (iii) the augment of the electric field strength leads to a blueshift of the spectra; (iv) for high electric fields the optical spectra show a shoulder-like feature, related with the occurrence of an anti-crossing between the two first excited levels.     

可溶性高聚物-多壁碳纳米管复合物的吸收光谱和光限幅性能研究

合成了三种可溶性高聚物嫁接的多壁碳纳米管复合物,包括聚乙烯基咔唑-多壁碳纳米管复合物(MWNTs-PVK),聚苯乙烯-多壁碳纳米管复合物(MWNTs-PSt)和聚甲基丙烯酸甲酯-多壁碳纳米管复合物(MWNTs-PMMA)。合成样品的TEM图显示出高聚物成功地包裹在碳纳米管外。样品的氯仿溶液UV-Vis 吸收谱显示,复合物的紫外区与纯的多壁碳纳米管不同,有一些复杂的特征吸收峰,反映了高聚物与碳纳米管共价连接的作用。利用Z扫描技术通过527 nm的纳秒激光脉冲激发研究了这三种复合物的非线性光学性质和光限幅性能。这三种复合物的氯仿溶液的光限幅性能很相似,并且优于纯多壁碳纳米管氯仿悬浮液和C60甲苯溶液。为解释观察到的结果,研究了样品的非线性折射,非线性吸收和非线性散射机制。结果显示,非线性吸收是引起样品光限幅的主要机制。     

Nonlinear responses and optical limiting behavior of fast green FCF dye under a low power CW He-Ne laser irradiation

The nonlinear responses and optical limiting performance of a dye type acid, called fast green FCF, are investigated under irradiation of 35 mW continuous wave He-Ne Laser. The second order refractive index and nonlinear absorption coefficient are measured by use of z-Scan technique. The optical limiting behavior is investigated by transmission measurement through the sample. Linear absorption coefficient (α), nonlinear absorption coefficient (β) and second order refractive index (n₂) of fast green FCF are measured at different concentrations.     

Z-Scan and Absorption Study of Crocin and Rhodamine B Decolorization by Bacterial Laccase

Dye decolorization is currently measured by the reduction of dye absorption, based on its linear optical properties in solution. However, this method is not suitable for high dye concentrations with linear attributes in the absorption spectra. In this work, nonlinear optical properties are used to study dye decolorization of Crocin and Rhodamine B treated with a bacterial laccase. For this purpose, the Z-scan was used to obtain the nonlinear refractive indices and nonlinear absorption coefficient of Rhodamine B and Crocin in the presence and absence of the bacterial laccase enzyme. The results showed that nonlinear optical properties could be used to study dye decolorization in solutions.     

Charge Transfer Photophysics of Tetra(α-amino) Zinc Phthalocyanine

The absorption, fluorescence, and transient absorption spectra of Tetra(α-amino) zinc phthalocyanine, ZnPc(α-NH₂)₄, have been measured in polar solvents and compared with that of ZnPc(α-R)₄ (R?=?H, NO₂, OCH(CH₃)₂). While the latter three showed the typical photophysics of phthalocyanines, ZnPc(α-NH₂)₄ exhibits distinct spectral properties, a very low fluorescence quantum yield and a relatively long fluorescence lifetime. These observations are explained by the substantial charge transfer characters in the absorption and fluorescence spectra of ZnPc(α-NH₂)₄. NMR indicates that intramolecular H-bonding makes atoms in NH₂ actually coplanar with other elements of ZnPc(α-NH₂)₄. The local excited state is non emissive and the weak emission is assigned to its charge transfer state. The transient absorption bands from laser flash photolysis located at 630 nm, 645 nm is assigned to the mono-charge transfer state, while that at 545 nm is assigned to the di-charge transfer state.