激基缔合物荧光法研究磺化聚苯乙烯在二氯乙烷中的链行为

通过测定磺化聚苯乙烯（ＳＰＳ）在二氯乙烷（ＤＣＥ）溶剂中的激发荧光光谱,分析了ＳＰＳ在ＤＣＥ中的链形态。极稀浓度时,只以单链形式存在;随浓度增加,ＳＰＳ以单链和激基缔合物形式存在;浓度再增加时,除了单链和激基缔合物外,还出现一种“类激基缔合物”,更高深度时,只出现尖激基缔合物”。     

环糊精对α，ω－双香豆素长链化合物分子内激基缔合物形成的影响

本文借助荧光光谱、吸收光谱、激发光谱以及单光子记数技术，通过环境效应、浓度效应、温度效应详细研究了环糊精对α，ω－双香豆素长链化合物分子内激基缔合物形成的影响，结果表明β－ＣＤ仅能加强香豆素单体的荧光发射与寿命，而γ－ＣＤ则可降低其形成激基缔合物的活化能，同时使其寿命得以延长．     

环糊精对α,ω—双香豆素长链化合物分子内激素缔合物形成的…

本文借助荧光光谱、吸收光谱、激光光谱以及单光子记数技术，通过环境效应、浓度效应、温度效应详细研究了环糊精对α，ω－双香豆长链人合物分子的缔合物怕影响，结果表明βＣＤ仅能加强香豆素单体的荧光发射与寿命，而γ－ＣＤ则可降低其形成激基缔合物的活化能，同时使其寿命得以延长。     

采用激基缔合物荧光寿命探究水性分散体成膜过程中粒子间分子链相互融合

为探究水性分散体成膜过程中粒子间分子链相互融合的过程,采用合成的芘丁酸二羟基丙酯作为荧光扩链剂,合成荧光标记型水性聚氨酯以及结构相近的未标记型水性聚氨酯,将荧光标记水性聚氨酯分散体与过量的非标记水性聚氨酯混合成膜,采用稳态瞬态荧光光谱仪测量纯标记分散体与其混合膜的激基缔合物的荧光寿命,通过建立激基缔合物荧光寿命和荧光物...     

用荧光光谱研究磺化PBMA-b-PSt嵌段离聚体在二氯乙烷溶液中的聚集行为

采用激基缔合物荧光方法研究了磺化度和浓度对磺化聚甲基丙烯酸丁酯－b-聚苯乙烯（SBMAS）在二氯乙烷（DCE）溶液中的聚集行为。随着磺化度增加，浓度增大，由于形成分子间聚集体的机会增加，聚合物分子链发生聚集的临界聚集浓度降低，最大发射波长发生红移，当磺化度摩尔分数大于5．01％时，由于分子链产生超级卷绕，受激生色团产生系间串跃，导致室温磷光产生，在荧光强度－浓度关系曲线上出现2个转折点。     

多足化合物的分子内激基缔合物形成及pH对其荧光的影响

研究了含萘脲基多足化合物溶液的稳态和瞬态光物理行为，由于分子内不同足间脲基的相互作用干扰了萘基的π-π叠合，使分子内萘基的激基缔合物生成受到影响，实验表明：由于三足化合物存在着给电子叔胺基因，因此当萘基被激发时，可因分子内的光诱导电子转移而导致荧光猝灭，正因如此，在三足化合物归一化后的稳态光谱中激基缔合物的发光强度很弱，用皮秒级单光子记数技术测得该化合物的瞬态荧光为三指数衰变过程，其中最长寿命的物种，即属于生成激基缔合物后再分解为萘激发态的部分仅占总量的4％，与稳态的结果相一致，工作表明对这类可用作荧光化学敏感器的三足化合物，如利用其激基缔合物的强度变化为其识别外来物种的敏感部位并不适合，相反。如引入的外来物种能影响化合物的分子内光诱导电子转移，进而影响萘基的发光强度，则是一较好的判别外来物种是否已进入主体的标志。     

双-β-萘甲酸多缩乙二醇酯在甲醇溶液中分子的构象和分子内激基缔合物的形成

本文研究了双-β-萘甲酸多缩乙二醇酯(P_n)在不同溶剂中的稳态和时间分辨荧光光谱。在甲醇中与在四氢呋喃中不同,P_n显示很强的激基缔合物荧光。表明在甲醇中疏水的两个末端发色团彼此靠近,亲水的多缩乙二醇链段包于两个发色团外部。热力学和动力学研究求出了P_n分子内激基缔合物形成的焓变是—20kJ/mol,活化能为～8.5kJ/mol,激基缔合物形成和离解的速度常数分别为4.5×10~8s~(-1)和3.1×10~8s~(-1)。     

环氧树脂改性磺化聚苯乙烯离聚物的合成与性能研究

用浓H2SO4、环氧对脂先后与废旧聚苯乙烯（PS）反应，研究了反应温度，催化剂用量对反应速度的影响，以及磺酸基含量，环氧树脂配比量对涂膜性能的影响，确定了合成反应的最佳条件：环氧基／磺酸基＝0．7：1．0，反应温度110℃，催化剂用量1％，转化率可达95％。     

有机化合物的光物理研究 ⅩⅢ.β-萘甲酸十六碳酯在L-B膜中基态二聚体及激基缔合物形成的研究

制备了β-萘甲酸十六碳酯的L-B膜。分别用Y型、Z型,以及含有硬脂酸的β-萘甲酸十六碳酯与单纯硬脂酸间隔挂法,将分子膜转移至石英载片上,研究了β-萘甲酸十六碳酯分子膜吸收以及荧光光谱。并与溶液和固态中的荧光光谱作了比较。在氯仿溶液以及在固态,β-萘甲酸十六碳酯只呈现其单体的荧光。然而,在L-B膜中,除了观察到单体的荧光外,还观察到了激发态二聚体以及激基缔合物发射的荧光。通过对β-萘甲酸十六碳酯分子膜进行热和水处理后,发现L-B膜中亲水层的介质环境有所改变,从而造成亲水层中的亲水基团的某些物理和化学性质的改变。根据实验事实,提出了β-萘甲酸十六碳酯二聚体和激基缔合物在L-B膜中形成的机制。     

Tacticity dependence of excimer formation in polystyrene solutions

Summary This work deals with the excimer formation in dilute solution for a series of polystyrenes of various tacticity prepared by epimerization of an initial isotactic sample. The main result is that the relative excimer yield remains equal to that obtained for iPS if the percentage of isotactic dyads is higher than 65%.The range of energy migration could be roughly approximated to 6 chromophores.     

Intramolecular excimer formation and energy migration in head-to-head polystyrene

Head-to-head polystyrene (HH-PS), in which the phenyl rings are separated by either two or four carbon atoms, displays predominantly fluorescence from monomeric units. No excimer emission is observable even when the polymer is dissolved in increasingly thermodynamically poorer solvents. This is strongly suggestive that excimer formation in normal head-to-tail polystyrene (HT-PS) occurs primarily between nearest-neighbouring chromophores. Intramolecular energy migration is shown to be negligible in both fluid and solid solutions of HH-PS. This is in direct contrast to the case with HT-PS in fluid solutions in which an energy migration coefficient of 7.5 × 10^?5 cm²s^?1 and an energy migration frequency of 4.1 × 10¹¹s^?1 were determined.     

Solution behavior of Na sulfonated polystyrene: Dipole moment determinations

Solution behavior of Na sulfonated polystyrene (NaSPS) ionomers with different percentages of sulfonate was studied by viscosity and dipole moment measurements. Two solvents of different character were chosen, i.e. dioxane (? = 2.22) and dimethyl formamide (DMF, ? = 36) and their mixtures. The reduced viscosity as a function of concentration in polar solvents reflects the ‘polyelectrolyte’ behaviour of the ionomers. Mean-squared dipole moment (<μ²>/x) values were calculated over a temperature range of 20–100°C, in dioxane and in a mixture of 4% DMF in dioxane. The results confirm the ‘polyelectrolyte’ behavior of ionomers by the addition of a small amount of polar cosolvent. The effect of increasing temperature on <μ²>/x in the DMF-dioxane mixture is attributed to the formation of a coordination complex.     

Electrical conduction in sulfonated polystyrene films

The d.c. electrical conductivity of 14% (by weight) sulfonated polystyrene films was measured as a function of temperature from 20° to 60°C in a 25-micron vacuum. Sulfonated films in the silver, cadmium, and methylene blue sorbed forms were prepared for these electrical measurements. Plots of log specific conductance versus reciprocal temperature gave straight lines with activation energies of 0.49 eV for methylene blue, 0.60 eV for Ag, and 0.98 eV for Cd. Large conductivity ansiotropies were also measured for the sulfonated polystyrene films in the Ag and methylene blue forms. Attempts with Hall-effect measurements to determine the sign and concentration of the charge carriers were unsuccessful. Photoconduction studies were also carried out with Ag-, Cd-, and methylene blue-doped sulfonated polystyrene films in the film lateral direction of highest photocurrent. Rise of photocurrent under d.c. illumination was found to be exponential with time constants of 29, 3.5, and 1.0 sec for Ag-, Cd-, and methylene blue-doped samples. The rise and decay of photocurrent in these films exhibited similar responses. Photocurrent was ohmic up to 400 V and varied linearly with light intensity up to 200 milliwatts.     

A study on the concentration dependence of excimer formation in pyrenyl labelled polystyrene solutions

The fluorescence of pyrenyl labelled polystyrene has been investigated. The ratio of excimer to monomer intensities (I_e/I_m) is found to vary tortuously with increasing concentration (C) and displays two critical concentration points, C⁺ at about 3.2 × 10⁻² g ml⁻¹ and C_m at about 0.32 g ml⁻¹. In the region C⁺ < C < C_m, an abrupt increase of I_e/I_m is revealed because of intermolecular interaction. At C > C_m, the sharp decrease of I_e/I_m is ascribed to entanglements of polymer chains. © 1999 Society of Chemical Industry     

磺化超细聚苯乙烯树脂的制备

采用微乳液聚合方法合成了纳米聚苯乙烯(PS)粒子,利用H_2SO_4和有机溶剂成功地对PS微乳液进行破乳。通过固相磺化反应,得到了超细聚苯乙烯阳离子交换树脂(SSPS)。通过测量和观察SSPS的粒径分布、微观形貌,以及利用红外光谱法测定树脂的磺化度,结果表明:SSPS树脂没有发生团聚,粒径控制在2μm以内,SSPS树脂的磺化度约为83%。     

Investigation of phase morphology,thermal behavior,and impact properties of polyamide-1010/polystyrene blends compatibilized by lightly sulfonated polystyrene ionomers

The phase morphology, thermal behavior, and impact properties of polyamide-1010 (PA)/polystyrene (PS) blends compatibilized by sulfonated polystyrene (HSPS) and their zinc salts (ZnSPS) were investigated, using a dynamic mechanical analyzer (DMA), a scanning electron microscope (SEM), a differential scanning calorimetry (DSC), and a pendulum impact tester. It was found that the addition of the ionomer had an improved effect on the phase morphology of the resulting blends, where the HSPS was a more effective compatibilizer than was the ZnSPS due to its low melt viscosity and less self-agglomeration in the PA matrix. DSC results showed that with increasing the ionomer content the amount of the less perfect crystals of PA increased in these blends and, hence, led to a small increase in the crystallinity of the PA phase. The crystallization rate of the PA in the resulting blends was accelerated slightly by the ZnSPS but was decreased by the HSPS, which was probably due to the nucleation effect of ZnSPS for PA but no nucleation of HSPS. The best improvement in the notched impact strength of the blends was achieved with the content of the ionomer up to 20 wt % based on the amount of PS. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 61–69, 1998