金属配位诱导体系Ca(DS)_2/C_(14)DMAO/H_2O的相行为和流变学

在室温(25.0±0.1℃)下,对十二烷基硫酸钙(Ca(DS)2)/十四烷基二甲基氧化胺(C14DMAO)体系在两种表面活性剂不同比例r(r=nCa(DS)2/nC14DMAO)下的水溶液进行了表面活性考察.当Ca(DS)2和C14DMAO结合形成复配体系时,溶液CMC值及在CMC时的表面张力都远低于C14DMAO溶液,说明Ca(DS)2和C14DMAO的缔合结构在水-空气界面的结合比单一表面活性剂更为紧密.在所考察的比例中,当r=2.0:10.0时,溶液CMC值及在CMC时的表面张力达到最低值,该比例处于囊泡相区域.当C14DMAO浓度固定时,随着Ca(DS)2的加入,首先形成了球状胶束相(L1-相),然后球状生长得到蠕虫状胶束相(L1-相),接着出现L1/Lα两相区,之后随Ca(DS)2浓度的进一步增大,得到了具有双折射现象的囊泡相区(Lαv-相),而后是凝胶相(gel),最后当Ca(DS)2过量时,不溶的Ca(DS)2在溶液中形成了沉淀.对囊泡相样品进行负染色透射电镜表征,观察到了多分散的囊泡结构,囊泡直径分布约在50～200nm范围内.各相区受温度影响变化非常显著.当温度升高时,在相同C14DMAO浓...     

Triton X-100六角液晶相中制备镁铝层状双金属氢氧化物纳米片及其药物载体应用

以Triton X-100 六角相溶致液晶作微反应器, 采用共沉淀法制备了镁铝层状双金属氢氧化物(LDHs)纳米薄片(L-LDHs). 以双氯芬酸钠(DS)为药物模型分子, 采用离子交换法制备了DS插层LDHs (DS/L-LDHs)纳米杂化物, 在37.0 ℃、pH=7.2的缓冲溶液中, 考察了纳米杂化物的药物释放性能, 并与传统溶液共沉淀法制备的镁铝LDHs (S-LDHs)纳米片状颗粒进行了对比. 采用粉末X射线衍射(XRD)、傅里叶变换红外(FT-IR)光谱、场发射扫描电镜(FE-SEM)、透射电镜(TEM)和N₂吸附-脱附等技术对所制备的LDHs和DS/LDHs 样品的晶体结构、比表面积、形貌特征等进行了表征. 结果表明, L-LDHs比S-LDHs具有更低的片厚度, 更高的比表面积和药物负载量, 所形成的DS/L-LDHs纳米杂化物药物释放速率也明显低于DS/S-LSHs, 即L-LDHs更适于作药物载体. DS/L-LDHs纳米杂化物的药物释放过程符合准二级动力学方程, 受颗粒内部扩散过程控制. 溶致液晶模板法可实现LDHs的形貌可控制备, 为LDHs基功能材料的研发提供了新途径.     

甲壳素类液晶高分子的研究Ⅵ.邻苯二甲酰化壳聚糖中酰胺酸取代度对液晶性的影响

通过控制不同反应时间和邻苯二甲酸酐 壳聚糖的摩尔比制备不同取代度的邻苯二甲酰化壳聚糖(PHCS) .用FTIR研究了反应机理和产物结构 ,观察到PHCS含两类取代即酰胺酸取代和酰亚胺取代 .反应时间较短时主要为前者 ,取代度表示为DS1 ;反应时间较长时主要为后者 ,取代度表示为DS2 .对PHCS在二氯乙酸 (DCA)中的液晶行为观察 ,结果表明 ,PHCS的临界浓度随DS1 的增加而显著增加 .DS1 对PHCS临界浓度的影响明显大于DS2 的影响 .基本上为酰胺酸取代的PHCS的临界浓度高于溶解度 ,以至于观察不到     

纤维素在离子液体中的均相乙酰化及其选择性

在1-烯丙基-3-甲基咪唑氯盐(AMIMCl)离子液体中进行了纤维素的均相乙酰化. 酯化剂为乙酸酐和乙酰氯以及加入或不加入催化剂吡啶. 用滴定法确定了产物的取代度(DS), 根据¹³C NMR考察了产物的取代度分布. 结果表明: 酰氯酰化的反应速度比酸酐快; 吡啶能加快乙酸酐的酯化反应, 但减慢酰氯的反应; 使用乙酸酐/吡啶酯化时所得产物具有特殊的取代度分布, 即DS_C-2>> DS _C-3.     

PREPARATION OF STARCH SUCCINATE WITH INTERMEDIATE DS BY AQUEOUS SLURRY REACTION

The succinylation of cornstarch by slurry reaction has been studied using sodium hydroxide as catalyst.Several reaction parameters affecting the succinylation were investigated including the concentration of starch in water,the ratio of succinic anhydride to starch,the reaction time and the reaction temperature,The favorable conditions for an intermediate degree of substitution(DS) and reasonably high reaction efficiency(RE) are pH 8.5-9.0,50% starch by weight to water.succinic anhydride to starch 1/1(w/w),reaction time 4h,reaction temperature 30℃ .Under these conditions,the DS of 0.45 and RE of 28% were achieved.The addition of an adequate amount of crosslinking agent imparted starch succinate water absorbency.     

双氯芬酸钠在石墨烯和室温离子液体复合修饰电极上的电化学行为及其测定

运用循环伏安法研究了双氯芬酸钠(DS)在石墨烯(Gene)和室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐(BMIMPF6)复合修饰电极上的电化学行为。DS在该复合电极上于0.65V处有一不可逆氧化峰。在40～200 mV/s范围内,其氧化峰电流与扫描速率平方根(v1/2)呈良好线性关系,表明电极过程是受扩散控制。测定了部分电极过程参数,优化了方波溶出伏安法(SWSV)的实验参数,DS浓度在1.0×10-7～1.0×10-4mol/L范围内与峰电流Ipa呈良好线性关系,检出限为8.0×10-8mol/L(S/N=3),加标回收率为95.7%～101.7%。     

SPEEK/PES-C、SPEEK/SPES-C共混质子交换膜研究

通过在磺化聚醚醚酮(SPEEK,DS=61.68%)中分别混入酚酞型聚醚砜(PES-C)、磺化酚酞型聚醚砜(SPES-C,DS=53.7%)制备出SPEEK/PES-C、SPEEK/SPES-C共混质子交换膜.结果表明,共混的两种聚合物之间均具有较好的相容性.PES-C、SPES-C的混入能有效降低膜的溶胀及甲醇透过,且随着共混量的增加,这种作用越趋明显.纯SPEEK膜在75℃左右溶解,而SPEEK/PES-C(30wt%)、SPEEK/SPES-C(30wt%)共混膜在80℃时溶胀度仅为22.5%、26.32%.在室温至80℃范围内,纯SPEEK及共混膜的甲醇透过系数都在10-7cm2.s-1数量级上,远小于Nafion115膜.在饱和湿度下,温度大于90℃时,SPEEK/PES-C(20wt%)共混膜电导率超过Nafion115膜;温度大于110℃时,SPEEK/SPES-C(30wt%)共混膜电导率与Nafion115膜相当,达到0.11S.cm-1.高电导率,低透醇系数以及明显提高了的可使用温度表明该类共混膜有望在DMFC中使用.     

色—质联用吹洗与捕集技术法测定水中挥发性有机污染物

参照美国环保局(U.S.E.P.A)提供的624法,研究了用Finnigan—MAT 5100型GC/MS/DS联用吹洗与捕集技术法测定水中挥发性有机物。1.使用0.2% Carbowax 1500涂于Carbopack C 上和用3% OV-1涂于Chromsorb 上的二种填充柱,直接测定5ml饮用水中有机物。共检出24种有机物,其中15种是属于EPA所规定的优先考虑的重点     

SPEEK/PES-C、SPEEK/SPES-C共混质子交换膜研究

通过在磺化聚醚醚酮(SPEEK,DS=61.68%)中分别混入酚酞型聚醚砜(PES-C)、磺化酚酞型聚醚砜(SPES-C,DS=53.7%)制备出SPEEK/PES-C、SPEEK/SPES-C共混质子交换膜.结果表明,共混的两种聚合物之间均具有较好的相容性.PES-C、SPES-C的混入能有效降低膜的溶胀及甲醇透过,且随着共混量的增加,这种作用越趋明显.纯SPEEK膜在75℃左右溶解,而SPEEK/PES-C(30 wt%)、SPEEK/SPES-C(30 wt%)共混膜在80℃时溶胀度仅为22.5%、26.32%.在室温至80℃范围内,纯SPEEK及共混膜的甲醇透过系数都在10-7 cm2·s-1数量级上,远小于Nation[R]115膜.在饱和湿度下,温度大于90℃时,SPEEK/PES-C(20 wt%)共混膜电导率超过Nation[R]115膜;温度大于110℃时,SPEEK/SPES-C(30 wt%)共混膜电导率与Nafion[R]115膜相当,达到0.11 S·cm-1.高电导率,低透醇系数以及明显提高了的可使用温度表明该类共混膜有望在DMFC中使用.     

含硫杂环结构氨基醇化合物的合成及缓蚀性能研究

以2-噻吩甲胺和乙二醇二缩水甘油醚为原料，在较温和的条件下，合成了一种结构新颖的含硫杂化结构的氨基醇化合物(DS)。分别用电化学法和失重法研究了DS在0.5 mol/L H₂SO₄溶液中对20#碳钢的腐蚀抑制作用。动电位极化曲线表明化合物DS在0.5 mol/L H₂SO₄溶液中以抑制阴极析氢反应为主，当DS浓度为50 mg/L时，对碳钢的缓蚀效率达到93%,具有用量小、缓释效率高的特点。吸附等温线研究表明：DS分子在碳钢表面的吸附行为符合Langumir单分子层吸附模型，既存在物理吸附，也存在化学吸附。化合物DS合成步骤简单、缓蚀效率高，在碳钢设备除锈、除垢等领域具有良好的应用前景。     

取代度和金属平衡离子对羧甲基纤维素热行为的影响

低取代度(DS<0.8)的NaCMC具有纤维素(Ⅱ)型的晶型结构,随DS增加结晶度迅速下降,DS>1时为无定形结构。其T_(?)随DS增加而降低,但DS=1.55的CMC的T_(?)则稍有提高。其起始分解温度(T_(?))随DS增加而增加,而分解活化能则与DS没有规律性的关系。CMC链上的平衡离子H~+、Na~+、Mg~+、Ca~+和Al~(3+)等对其结晶形态的破坏能力不同,对相同价数的离子,随离子半径增大,破坏力增强,而对半径相近的离子,高价的比低价的破坏作用明显。NaCMC的分解活化能E=251～293 kJ/mol,而高价平衡离子的CMC的E=105 kJ/mol左右。     

十二烷基磺酸根插层水滑石负载纳米钯催化的 Suzuki 偶联反应

 首次制备了十二烷基硫酸根 (DS–) 插层水滑石负载的纳米钯无膦配体型的 Suzuki 偶联反应催化剂. DS–进入到水滑石层间, 使层间距从微孔增至 2.9 nm, 从而有利于中等尺度的有机分子在催化剂表面的扩散. 进一步以 PdCl42–交换该水滑石得到 DS–和 PdCl42– 双插层的水滑石. 还原后可得到层间插有金属钯纳米团簇的水滑石. 由于 DS–插层后在水滑石层板间形成的空间有限, 限制了 Pd0 团簇的进一步生长. 作为一种亲油性的非均相催化剂, 该类催化剂可有效促进卤代芳烃与苯硼酸的 Suzuki 偶联反应. 催化剂循环使用 5 次后活性基本得以保持.     

Simultaneous LC-MS/MS Determination of Danshensu and Paeoniflorin for Permeability Studies in Caco-2 Intestinal Absorption Model

A high sensitive method based on liquid chromatography tandem mass spectrometry（LC-MS/MS） was developed and validated for the study of permeability of danshensu（DS） and paeoniflorin（PF） in Caco-2 intestinal absorption model. The DS and PF were extracted from cell culture by vacuum-lyophilizing and then separated on a Zorbax Stable Bond C18 column with 0.1% acetic acid aqueous solution and methanol as mobile phase. Detection was carried out by negative electrospray ionization（ESI ） with selected reaction monitoring（SRM） mode. The apparent permeability coefficients（Papp） of DS and PF in Caco-2 cell medium were calculated and the effects of verapamil on the coefficients Papp of the two test compounds were also illustrated. The permeability of PF was much better than that of DS when the two compounds were administrated individually. Co-administration of DS and PF led to the decrease of the transport from apical side to basolateral side for both the compounds. However, the transport in the contrary direction were accelerated. It was also observed that verapamil could accelerate the transport of the test compounds from apical side to basolateral side. However, the absorption-enhanced effect of verapamil was attenuated when DS and PF were co-administrated. These observations suggest that both passive diffusion and active efflux involved in P-gp would effect the passage of DS and PF across Caco-2 cell monolayer. At the same time, the co-administration of DS and PF to an alteration of transport behavior, which suggests that the interaction must be taken into account when ‘n-in-one＇ samples were used in Caco-2 intestinal model.     

Chiral separation abilities of homogeneously synthesized cellulose 3,5-dimethylphenylcarbamates: Influences of degree of substitution and molecular weight

A series of cellulose 3,5-dimethylphenylcarbamates(CDMPCs) with different degrees of substitution(DS) and degrees of polymerization(DP) were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride(Amim Cl). Then, the CDMPCs were coated on silica gel and used as chiral stationary phases(CSPs), and their chiral recognition abilities for seven racemates were evaluated by high performance liquid chromatography. The results showed that DS and DP of CDMPCs had a great influence on chiral recognition abilities of the CSPs. The CSPs with the DS ≈ 1 gives a low chiral recognition to most racemates. On the contrast, the CSPs with the DS ? 2 exhibited high chiral separation abilities. For example, six racemates could be separated on the CSP with CDMPC of DS ≈ 2(CSP-2). Especially, for the enantioseparation of 1-(2-naphthyl) ethanol and Tr?ger's base, CSP-2 gave the highest separation ability in all of CSPs. On the other hand, when the DP of cellulose was in a range from 39 to 220, the chiral separation abilities of CDMPCs increased as the DP increased. This work demonstrates that the structure of cellulose esters such as DS and DP has important effect on their chiral separation ability, and therefore provides a practical method to design and prepare desirable CSPs for different racemates.     

(1R,2R)环己二胺Schiff碱双核配合物的合成与表征

合成了二(3-羧基水杨醛叉)缩(1R,2R)环己二胺Sch iff碱配体(H4DS)及其Cu(Ⅱ)和N i(Ⅱ)的同双核配合物.用元素分析,IR光谱和1H NMR对配合物的组成和结构进行了表征;用循环伏安法测定了配合物Cu2DS.2H2O的电化学性质.     

Studies on Sulfation of Lycium barbarum Polysaccharides

Polysaccharides can anti-virus, such as human immunodeficiency virus (HIV-1),[1] herpes simplex virus (HSV-1,HSV-2) and cytomegalovirus. Some of them are sulfates, e.g. dextran sulfate, heparin, sulfonation of chitosan and sulfated derivatives of Lentinan. Our results showed that sulfated derivatives of Lycium barbarum polysaccharides (LBP)have anti-HIV activity. Because the anti-HIV activity of LBP was deeply dependent on the molecular weight, the sulfation pattern and glycosidic branches besides degree of sulfation (DS), so we emphasized our work on the factors of DS.     

DMFC用PES/SPEEK共混阻醇质子交换膜

将磺化聚醚醚酮(SPEEK, 磺化度DS为68.3%)和聚醚砜(PES)两种聚合物共混制得PES/SPEEK共混膜. DSC研究表明两种聚合物之间具有较好的相容性, 因而共混膜均匀致密, 未发生大尺度相分离. PES的混入能有效降低膜的溶胀度及甲醇透过系数. 纯SPEEK 膜40 ℃时在1 mol•L−1甲醇水溶液中溶胀度达到160%, 45 ℃时就完全溶解, 而含30%(w)PES的共混膜在80 ℃时的溶胀度仅有15%. 室温下含20%−30%(w)PES的共混膜的甲醇透过系数为1×10−7 cm2•s−1左右, 比Nafion 115膜的透过系数小一个数量级. 尽管80 ℃下30%(w)PES/SPEEK共混膜的电导率与Nafion 115膜相当, 但由于共混膜的厚度比Nafion 115膜小1/3左右, 膜电阻较小, 因而其电池性能比Nafion 115膜的好.     

Effect of Molecular Structure on the GasPermeability of Cellulose Aliphatate Esters简

In this work, four kinds of cellulose aliphatate esters, cellulose acetate （CA）, cellulose propionate （CP）, cellulose butyrate （CB） and cellulose acetate butyrate （CAB） are synthesized by the homogeneous acylation reactions in cellulose/AmimC1 solutions. These cellulose aliphatate esters are used to prepare gas separation membranes and the effects of molecular structure, such as substituent type, degree of substitution （DS） and distribution of substituents, on the gas permeability are studied. For CAs, as the DS increases, their gas permeabilities for all five gases （02, N2, CH4, CO and CO2） increase, and the ideal permselectivity significantly increases first and then slightly decreases. At similar DS value, the homogenously synthesized CA （distribution order of acetate substituent： C6 〉 C3 〉 C2） is superior to the heterogeneously synthesized CA （distribution order of acetate substituent： C3 〉 C2 〉 C6） in gas separation. With the increase of chain length of aliphatate substituents from acetate to propionate, and to butyrate, the gas permeability of cellulose aliphatate esters gradually increases. The cellulose mixed ester CAB with short acetate groups and relatively long butyrate groups exhibits higher gas permeability or better permselectivity than individual CA or CB via the alteration of the DS of two substituents.     

SYNTHESIS AND PROPERTIES OF SULFONATED POLY(ETHER KETONE)S CONTAINING 3,5-DIMETHYL PHTHALAZINONE MOIETIES AS PROTON EXCHANGE MEMBRANE MATERIALS

Sulfonated poly（ether ketone）s containing 3,5-dimethyl phthalazinone moieties（SPPEK-DMs）with different degrees of sulfonation（DS）were synthesized via direct polycondensation from 4-（3,5-dimethyl-4-hydroxyphenyl）-2,3- phthalazinone,4,4’-difluorobenzophenone and 3,3’-disulfonate-4,4’-difluorobenzophenone.The chemical structure of SPPEK-DMs was characterized by FTIR and ¹H-NMR.Thermal stability of SPPEK-DMs was characterized by the thermogravimetric analysis.The membranes prepared from SPPEK-DMs exhibited ion exchange capacities（IEC）ranging from 0.93 mmol·g^-1to 1.86 mmol·g^-1.Water uptake,swelling,oxidative stability and methanol permeability of SPPEKDMs membranes were investigated.SPPEK-DMs membranes exhibited high oxidative stability.The methanol permeability values of SPPEK-DMs membranes were in the ranee 5.15×10^-8-6.61×10^-7cm s,which was much lower than those of Nafionl 17.The proton conductivity of SPPEK-DM40 membranes was 1.1×10^-2Scm^-1at 70℃.     

Crystallization Behavior and Thermal Properties of PP/MgAl LDH Nanocomposites Prepared in Non-polar Solution

Polypropylene(PP)/MgAl layered double hydroxide(MgAl LDH) nanocomposites were synthesized by refluxing PP and dodecyl sulfate-intercalated MgAl LDH[MgAl(DS)] in non-polar xylene. Their structure, thermal and crystallization properties were studied via X-ray diffraction(XRD), transmission electron microscopy(TEM), thermogravimetric analysis(TGA), differential scanning calorimetry(DSC), and polarized light microscopy(PLM). The nanoscaled dispersion of MgAl(DS) nanolayeres in the PP matrix was verified by the disappearance of the d(003) XRD diffraction peak of MgAl(DS) and observation of TEM image. The DSC data show that the SDS/LDH inorganic components negatively affect the crystallization properties of PP and decrease the size of PP spherulites because the inorganic components act as additional nuclei. The PP/MgAl LDH nanocomposites have a faster charring progress in a temperature range of 250―430 °C and a better thermal stability above 320 °C than pure PP.