光谱分析在含1,3,4-噁二唑环质子交换膜领域中的应用

采用直接缩聚的方法,通过调节磺化单体与非磺化单体的比例合成出一系列含有1,3,4-噁二唑的聚芳醚砜聚合物。并且通过红外光谱,核磁共振谱,热失重分析仪对其结构进行验证。红外光谱在1 603cm-1出现了CN的特征吸收峰,验证了噁二唑环的结构,又经1 H NMR进一步验证了其聚合物的结构,说明已经成功在聚合物中引入了1,3,4-噁二唑环。热失重有两个明显的失重平台,在300和450℃分别为磺酸基团和聚合物骨架的断裂,展现了良好的热性能,满足作为质子交换膜的基本要求。     

傅里叶变换红外光谱应用于乳腺癌临床诊断的探索

应用了ATR探头测定了10例正常乳腺组织块和8例乳腺癌组织块的傅里叶变换红外(FTIR)光谱,用统计学的方法详细比较了乳腺癌组织与正常乳腺组织的13条谱带的19个红外光谱指标的差异。结果表明：乳腺癌组织的红外光谱中与蛋白质、脂类、碳水化合物和核酸相关的谱带同正常乳腺组织之间存在明显的差异：(1)N—H的相对强度明显增高,蛋白质酰胺Ⅰ带显著红移。(2)—CH₂基团的对称伸缩振动和反对称伸缩振动以及CO的伸缩振动明显减少;(—CH₂)_n变角振动的相对强度降低。(3)1 160 cm-1谱带与1 120 cm-1谱带的相对强度明显降低。(4)1 080 cm-1谱带红移。这些差异是应用红外光谱诊断乳腺癌的基础。FTIR光谱在乳腺癌的临床诊断和治疗方面有着十分美好的前景。     

紫外光引发阳离子聚丙烯酰胺的红外光谱研究

以丙烯酰胺(AM)、 丙烯酰氧基乙基三甲基氯化铵(DAC)、 丙烯酸丁酯(BA)为单体,采用紫外光引发聚合制备阳离子聚丙烯酰胺P(AM-DAC-BA)。 采用紫外光谱和红外光谱研究其结构特征;分析AM,DAC,BA,P(AM-DAC-BA)的红外光谱中的典型红外振动频率的归属。 通过与单体红外光谱比较得出：由于聚合产物的对称性增加,聚合产物红外光谱更加简单。 P(AM-DAC-BA)的特性粘度随着光强、 BA含量、 光引发剂浓度、 光照时间的增加而增加。 选取AM,DAC,BA中的—CONH₂,—COOCH₂(CO), —COOCH₂—(C—O—C),—CH₂—N+(CH₃)₃基团吸收峰为特征吸收峰,随着光强、 BA含量的增加,特征峰面积增加;随着光引发剂浓度增加特征峰面积却呈现减少趋势;随着光照时间增加,峰面积是先减小后增加。 但不同P(AM-DAC-BA)在红外光谱上对应的特征吸收峰的峰型类似,特征峰位置基本一致。     

磺化聚苯乙烯(SPS)及其离聚物的光谱特性

取苯乙烯磺化及离子化后其红外光谱产生一系列特征变化,磺化度不同的聚苯乙烯其磺酸基团伸缩振动强度不同。磺化度的提高会引起磺化聚苯乙烯（ＳＰＳ）红外光谱的分裂。本外本文还就磺化聚苯乙烯及其离聚体的二氯甲烷溶液的荧光发射谱进行了讨论,结果表明,磺化程度和离子化对聚合物的荧光发射峰的强度和位置都有一定影响。     

鼻咽癌患者指甲的红外光谱研究

利用傅里叶红外光谱研究了20例正常人和3例鼻咽癌患者手指甲的红外光谱,结果表明：癌指甲样品与正常指甲样品的红外光谱在峰形、峰强度、峰频率等方面均存在明显差异;它们的最大区别是：酰氨Ⅱ带峰形的变化,δ_s(CH₃)峰的消失,以及874.0 cm-1附近有无吸收峰。还着重研究了磷酸二酯基团的对称和反对称伸缩振动;以及C—O基团伸缩振动峰的变化。并从蛋白质、核酸氢键的角度以及膜脂碳氢链排列及构像变化角度等方面分析了发生变化的原因。磷酸二酯基团的对称伸缩振动峰呈现有规律的变化, 即癌样品由1 080.0位移到1 077.6 cm-1, 反对称伸缩振动由1 239.4位移到1 238.4 cm-1, 表明指甲核酸分子内磷酸二酯键骨架的结构发生了改变。另外, 膜脂分子中的CH₂弯曲振动 δ(CH₂)的波数也有些改变, 即癌样品由1 453.1位移到1 453.7 cm-1。而且,峰的强度也有所增强, 说明癌患者指甲的膜脂中亚甲基链的无序状态较正常人的大。     

不同物料和炭化方式制备生物炭结构性质的FTIR研究

红外光谱是了解生物炭结构性质特征的重要手段。通过采用傅里叶红外光谱技术(FTIR)对不同物料和制备方式的生物炭结构性质特征进行表征。结果表明：不同的物料制备的生物炭均具有羟基、芳香基及一些含氧基团的吸收峰,与活性碳有共同特征;但其他吸收峰,有着显著差异。高温炭化可以使玉米秸秆中—OH,—CH₃,—CH₂—,CO间发生缔合或消除,促进了芳香基团的形成。在不同炭化方式下,加热和微波炭化,对生物炭形成有着机理上差别,加热炭化可致使醇、酚中的—OH彼此结合或者消除,形成苯环类基团,而微波法能使得芳香基团钝化阻止其参与反应,使得苯环类物质得以更多形成。综上表明,红外光谱可较好反映生物炭的结构特征,揭示了生物炭主要含有—OH、芳香基团等活性基团。     

DL-2-氨基4-磺酸基-丁酸与金属离子相互作用的研究

运用傅里叶变换红外光谱技术,对DL-2-氨基-4-磺酸基丁酸(DLH)与Na+,Cu2+,Zn2+和Ni2+ 形成的配合物进行了研究,并用元素分析的方法确定配合物的组成。红外光谱显示DLH分子中的—COOH,—NH+₃和—SO-₃ 基团均可与金属离子发生直接或间接的相互作用。不同过渡金属离子与氨基、羧基相互作用的强度顺序均为： Cu2+＞Zn2+＞Ni2+,其中羧基与不同离子可能采取了不同的配位方式。     

甲基对硫磷分子印迹聚合物光谱研究

以甲基对硫磷为模板分子,分别以甲基丙烯酸、丙烯酰胺和4-乙烯基吡啶为功能单体,合成了三种分子印迹聚合物。利用紫外光谱研究了甲基对硫磷与不同功能单体间作用力的大小,表明4-乙烯基吡啶与甲基对硫磷间的作用力明显强于另外两种单体。红外光谱研究表明4-乙烯基吡啶可以同模板分子的P—O—C和—NO₂部位发生反应,并形成稳定的共价化合物,而另外两种单体仅在P—O—C部位与模板分子缔合。此外,由三种分子印迹聚合物的红外光谱图可以看出,在聚合物表面确实存在着可与模板分子相互作用的官能团。     

结节性甲状腺肿的傅里叶变换红外光谱体表测定

利用ATR探头和中红外光导纤维红外光谱法在体表测定34个正常甲状腺和20个结节性甲状腺肿的傅里叶变换红外光谱。并比较了二者之间13条谱带的27个指标的差异。结果表明: 结节性甲状腺肿的体表红外光谱中：(1)～2 925 cm-1 谱带(—CH₂的反对称伸缩振动)的峰位, ～1 250 cm-1(PO的伸缩振动)谱带的峰位均明显地向低波数方向移动(P＜0.05);(2)谱带的相对强度(谱峰高度)比值H_{1 740}/H_{1 460}, H_{1 160}/Ｈ_{1 460}和H_{1 160}/H_{1 120} 较正常甲状腺明显降低(P＜0.05);(3)H_{1 080}/H_{1 460}比值明显升高(P=0.008)。这些差异是利用体表红外光谱诊断结节性甲状腺肿的基础。     

香豆素型荧光聚合物的合成及光学性能

以对甲苯磺酸为催化剂,通过Pechmann法使间苯二酚和乙酰乙酸乙酯发生脱水缩合反应,合成了7-羟基-4-甲基香豆素,再以三聚氯氰为交联单体,将7-羟基-4-甲基香豆素和紫外线吸收剂2,4-二羟基-二苯甲酮引入同一分子中,并使其与丙烯酰胺按一定比例聚合,得到一种能溶于水的荧光聚合物。通过红外光谱和核磁氢谱对产物进行结构表征,运用紫外光谱、荧光光谱测试其光学特性,并考察其在纸张上的应用效果。结果表明:荧光聚合物的Stokes位移(3 121.2 cm-1)比单体(5 221.5 cm-1)小,空间位置变化小,损失能量低,说明其结构更稳定,光稳定性更好,应用于纸张的抗紫外光老化效果也更优。     

SAXS cluster structure and properties of sPEEK/PEI composite membranes for DMFC applications

Sulfonated poly(ether ether ketone)/polyethyleneimine (sPEEK/PEI) composite membranes were prepared to reduce the water uptake and methanol permeability of highly sulfonated PEEK membranes (> 65%). Incorporation of small amounts of PEI reduced ionic cluster size via electrostatic complex formation between anionic sulfonic groups of the sPEEK and the cationic amine groups of the PEI, and thus affected membrane properties considerably. Ion cluster size decreased with increasing PEI concentration by small angle X-ray scattering pattern. Addition of 1 wt.% of PEI resulted in reduction of water uptake and methanol permeability by 30% at 60 °C and 85% at room temperature, respectively. The thermal and mechanical stabilities were also enhanced by formation of physical cross-linking induced by electrostatic interactions between acid/base polymers. Although proton conductivity was also reduced by PEI incorporation as a part of the sulfonic acid groups involved in ionic complex formation, its effect on proton conductivity was not as strong as on methanol permeability.     

Strengthen the performance of sulfonated poly(ether ether ketone) as proton exchange membranes with phosphonic acid functionalized carbon nanotubes

Nanocomposite polymers based on phosphonic acid functionalized carbon nanotubes (CNT-POH) and sulfonated poly(ether ether ketone) (SPEEK) have been fabricated and employed as highly efficient proton exchange membranes. CNT-POH were synthesized through the grafting of carbon nanotubes (CNT) with diethylphosphatoethyl triethoxysilane and subsequent acidification of phosphate to phosphonic acid ligands. Incorporating CNT-POH into SPEEK matrix improves the proton conductivity at different temperatures and relative humidity, which can be attributed to the homogeneous dispersion of highly hydrophilic phosphonic acid groups and the formation of proton transport channels in the membrane. The methanol permeability of the composite membranes is also decreased, owing to the increased tortuosity of the methanol transport channel. The CNT in SPEEK matrix also enhance the dimensional stability and mechanical property remarkably. Consequently, this phosphonic acid functionalized CNT/SPEEK composite membrane (SPEEK-POH) is a potential candidate for application in direct methanol fuel cells (DMFC).     

Sulfonated Aromatic Polymers and Organically Modified Montmorillonite Nanocomposite Membranes for Fuel Cells Applications

Aromatic polymers, such as sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO), sulfonated poly(ether ether ketone) (SPEEK), and sulfonated poly(ether sulfone) (SPES), at the optimum degrees of sulfonation (DS), are suggested and evaluated as alternatives to Nafion for direct methanol fuel cells (DMFCs) applications. To reduce the methanol cross-over, which decreases the efficiency of the cell, organically modified montmorillonite nanoclays (OMMT) were added at 1 wt% to the sulfonated matrices with the optimum DS. The X-ray diffraction (XRD) patterns of nanocomposite membranes proved that the nanoclay layers were exfoliated. The proton conductivity and methanol permeability of the membranes, as well as the ion-exchange capacity (IEC), were measured. The selectivity parameter, ratio of proton conductivity to methanol permeability, was identified at 25°C for the nanocomposite membranes and the results were compared with Nafion117. Finally, the DMFC performance tests were investigated at 70°C and 5 M methanol feed for the manufactured nanocomposite polyelectrolyte membranes (PEMs). The SPEEK-based nanocomposite membrane showed the highest maximum power density in comparison with Nafion 117 and SPES and SPPO nanocomposite membranes. The results indicated that the nanocomposite membranes were promising PEMs for DMFC applications.     

Preparation and properties of crosslinked hybrid proton exchange membrane based on sulfonated poly (arylene ether nitrile) with improved selectivity for fuel cell application

Novel sulfonated poly (arylene ether nitrile) with pendant carboxylic group copolymers have been prepared as proton exchange membranes which were applied in direct methanol fuel cells (DMFCs). Compared with others, this work shows two main advantages: the crosslinked method is uncomplicated and the membranes were prepared via the hydroquinonesulfonic acid potassium salt (SHQ) as crosslinker mingled in sulfonated poly (arylene ether nitrile) (SPEN) to avoid the decrease of proton conductivity. The obtained crosslinked membranes exhibited improved dimensional stability; larger tensile strength than that of pure SPEN; and good thermal, mechanical properties. Furthermore, after crosslinking, the membranes had low methanol permeability values (0.78–3.4 × 10^?7 cm² s^?1) and displayed good proton conductivities in the range of 0.0328–0.0385 S·cm^?1 at room temperature. The sample of SPEN-SHQ-5 % showed highest selectivity value of 4.205 × 10⁵ S·s cm^?3, which was 11.9 times higher than that of Nafion 117. All of these results indicated that these membranes would be the potential candidates as proton exchange membranes (PEMs) in DMFCs.     

Association Phenomena of Poly(arylene ether sulfone)s in Dimethylformamide

Three poly(arylene ether sulfone)s (two polymers and one copolymer) containing diphenylfluorene, phenolphthalein and 2,4-bis[(4-chlorophenyl)sulfonyl]-1-(phenyltio) benzene)] units were synthesized by the classical Williamson polyetherification reaction. The association phenomenon in N,N-dimethylformamide (DMF) was investigated by different methods: gel permeation chromatography (GPC), viscosity, atomic force microscopy (AFM), fluorescence spectroscopy and dynamic light scattering (DLS). Both AFM and DLS measurements evidenced the formation of aggregates with spherical or ellipsoidal shape at a concentration around 0.05 wt.%. This behavior could be explained by dipole-dipole interactions between macromolecular chains, probably with the participation of solvent molecules, and by H-bonds involving hydroxyl end groups.     

Design of novel SPEEK-based proton exchange membranes by self-assembly method for fuel cells

Fuel cell represents a new energy conversion device, which promises to provide clean source of power. Fuel cell [particularly proton exchange membrane fuel cell and direct methanol fuel cell (DMFC)] is a promising candidate for transportation and portable power source applications. In DMFC, there is a problem of methanol crossover. In order to reduce such a problem, there has been an intensive research activity in the modification of Nafion. In the present investigation, self-assembled membranes were fabricated with sulfonated polyether ether ketone as the core part of the membrane. Aminated polysulfone and sulfonated polysulfone were used as the layers in order to prevent the crossover of methanol. The assembled membranes were characterized by ion exchange capacity, water and methanol absorption, and durability. The methanol permeability and selectivity ratio proved a strong influence on DMFC application. Scanning electron microscopy proved smooth surface, which established strong cohesive force for the polymer chains. Among the synthesized self-assembled membranes, the membrane with two bilayers was the best in terms of power density in DMFC. The membrane electrode assembly with two bilayers showed higher performance (~61.05 mW/cm²) than sulfonated poly(ether ether ketone) and Nafion in DMFC.     

A novel sulfonated dendritic polymer as the acidic component in proton conducting membranes

The present study involves the synthesis of sulfonated poly(3-ethyl-3-(hydroxymethyl)oxetane), sPTMPO, by end-capping the hydroxy-groups in the PTMPO with 1,4-butane sultone. A series of the polymer with different degrees of substitution was investigated. Furthermore, the subsequent use of the sulfonated PTMPO as the acidic component in proton conducting membranes was explored. The membranes were prepared by either a) mixing the partly sulfonated PTMPO with hexamethoxymethyl melamine (HMMM) to form cross-links by ether formation between the methylol groups on HMMM and the remaining hydroxyl groups on the hyperbranched polyether or b) using the sulfonated polyether in conjunction with a pyridine functionalised polysulfone, PSU-pyridine, to produce acid–base blend membranes. Membrane properties such as proton conductivity, water uptake and mechanical properties are discussed.     

Intrinsically proton-conducting comb-like copolymers with benzimidazole tethered to the side chains

Intrinsically proton-conducting comb-like copolymers having side chains tethered with benzimidazole units have been prepared and characterized with respect to their thermal properties and proton conductivity. In the first step of the preparation, poly(4-hydroxystyrene) was synthesized by polymerization of tert-butoxystyrene followed by hydrolysis of the butoxy groups. In the next step, poly(allyl glycidyl ether) side chains were grafted from the polyhydroxystyrene (PHSt) backbone. Finally, benzimidazole units were tethered via free radical thiol-ene coupling between 2-(2-benzimidazolyl)ethanethiol and the pendant allyl groups of the side chains. The efficiency of the thiol-ene coupling reaction was found to decrease with increasing length of the side chains, which was attributed to sterical effects. The materials were thermally crosslinkable, most probably via the residual allyl groups. Calorimetry showed that the benzimidazole-tethered copolymers had glass transition temperatures of 50– 60 °C, partly a consequence of the strong hydrogen bonds between the benzimidazole units. The proton conductivity of the fully polymeric materials exhibited a non-Arrhenius behavior and a maximum conductivity of 6.6 μS/cm was reached at 160 °C under anhydrous conditions.     

二氮杂萘酮衍生物的核磁共振结构鉴定

用¹H, ¹³C NMR及多种二维核磁共振谱确定了一系列新合成的二氮杂萘酮衍生物的结构,完成了¹H和¹³C NMR 谱的归属,给出了该系列衍生物的氢、碳原子的准
确化学位移.     

Optical properties of polymer poly(phthalazinone ether sulfone ketone) film waveguide

The optical properties of novel polymer poly(phthalazinone ether sulfone ketone, PPESK) film waveguide are studied by prism coupler. The optical properties of PPESK-8020, including refractive index, birefringence, thermo-optical coefficient and optical loss, are demonstrated. This kind of material has the advantages of low optical loss (less than 0.24 dB/cm at 1310 nm and 0.52 dB/cm at 1550 nm) and high thermal stability (1% weight loss temperature: 488 ℃). Due to these excellent properties, it may have great potential in optical waveguide applications.