耐盐性海藻酸钙纤维的制备及性能研究

针对海藻酸钙在盐溶液中易溶问题,利用戊二醛交联反应制备了耐盐海藻酸钙纤维,红外光谱及溶胀度的测试证明发生了缩合交联反应;讨论了不同工艺条件下,改性纤维的溶胀度和力学性能。结果表明,最佳合成条件为温度30℃、交联剂含量8%、反应时间3.0h、pH=5;改性海藻酸钙纤维的溶胀度只有98%,为纯海藻酸钙纤维的27%,改性纤维断裂强度为2.23cN/dtex。     

海藻酸钙水凝胶对电刺激的响应行为

以CaCl2为交联剂采用浸渍法制备了海藻酸钙水凝胶，研究了海藻酸钙水凝胶的溶胀吸水率及其电刺激响应行为．结果表明，在NaCl水溶液中，海藻酸钙水凝胶的平衡溶胀比随着NaCl溶液浓度的增大而增大，随着交联剂CaCl2溶液浓度的增大而减小．海藻酸钙水凝胶在NaCl水溶液中在非接触直流电场作用下向负极弯曲，其弯曲速度、弯曲偏转程度和应变随着外加电场强度的增大而增大，随着NaCl溶液离子强度的变化在离子强度I=0．03时出现临界最大值，随着交联剂CaCl2溶液浓度的增大而减小．在周期性电场作用下，海藻酸钙水凝胶的弯曲响应行为具有良好的可逆性．     

聚乙烯醇/海藻酸钙共混膜的制备及耐水性能研究

以聚乙烯醇、海藻酸钠为主要原料,CaCl_2为交联剂,制备了聚乙烯醇/海藻酸钙共混膜。以溶胀度为主要指标,分析了聚乙烯醇的含量与交联剂浓度对共混膜耐水性能的影响,并对聚乙烯醇/海藻酸钙共混膜的微观形貌进行了表征.研究结果表明,当聚乙烯醇的质量分数为60%,交联剂质量分数为2%时,体系的交联效果改善显著,共混膜具有较高的耐水性、亲水性与保水率;扫描电镜与原子力显微镜结果显示聚乙烯醇和海藻酸钙之间有良好的相容性,共混膜的表面粗糙度提高.该研究将为聚乙烯醇/海藻酸钙共混膜的实际应用提供一定的理论基础.     

氧化海藻酸钠交联海藻酸钙/明胶(半)互穿网络的制备及热稳定性研究

以自制的氧化海藻酸钠为交联剂,制备了海藻酸钙/明胶(半)互穿网络,采用红外光谱表征了(半)互穿网络的结构;通过热重分析研究了海藻酸钙/明胶(半)互穿网络的热稳定性,解释了两者共混过程中的作用机理;并与戊二醛为交联剂制备的海藻酸钙/明胶(半)互穿网络的热稳定性进行了比较。研究结果表明,两种交联剂制备的(半)互穿网络的结构与热稳定性相似,氧化海藻酸钠可以取代毒性较大的戊二醛交联明胶制备海藻酸钙/明胶(半)互穿网络;海藻酸与明胶在共混的过程中发生了物理或化学反应。     

制备无硫可膨胀石墨的研究

用硝酸（65％）和乙酸酐混合液、高锰酸钾和天然鳞片石墨反应制备无硫可膨胀石墨,最佳反应条件是：石墨、乙酸酐、硝酸、高锰酸钾的重量比为1：0．8：0．5：0．07,反应时间为40min,反应温度为30℃,可膨胀石墨的膨胀容积为280mL／g;不含硫,含氮量为1．27％,其终端产品柔性石墨不含氮．迄今为止,未见文献报道．     

制备复方环丙沙星膜剂及含量测定方法研究

目的：制备复方环丙沙星膜剂并制定该制剂的含量测定方法。方法：以聚乙烯醇-124、羧甲基纤维索钠为成膜材料,制备复方环丙沙星膜剂。采用等吸收双波长紫外分光光度法进行含量测定。结果：环丙沙星浓度测定的线性范围为4-9gmL^-1,r=0．9997（n=6）,平均回收率98．06％,RSD为1．04％替硝唑浓度测定的线性范围8～18gmL^-1,r=0．9989（n=6）,平均回收率99．17％,RSD为0．82％。结论：复方环丙沙星膜剂制备工艺可行,含量测定方法准确可靠,可达到质量控制的目的。     

聚乙烯醇复合膜的制备

以亲水性的聚乙烯醇为原料，采用机械涂敷法制备复合纳滤膜．考查了基膜、聚乙烯醇的浓度、交联剂的浓度及配比、涂层厚度、交联时间以及热处理等对膜分离性能的影响，确定了最终制备条件．在一定的温度和湿度条件下，在截留相对分子质量为100000的基膜上，通过5％的聚乙烯醇溶液与1％的戊二醛的交联反应，研制了截留相对分子质量为600的PVA复合纳滤膜。     

近零膨胀ZrO2-ZrW2O8复合材料的制备和表征

以分析纯ZrO2和WO3为原料，通过原位反应法成功制备了ZrO2-ZrW2O8复合材料，研究了其热膨胀性能，并探讨了烧结助剂AJ203对其致密度的影响。采用X射线衍射仪（XRD）、扫描电镜（SEM）和热膨胀仪对制备的样品进行表征。研究结果表明：制备的复合材料的组元为α-ZrW2O8和m-ZrO2；其中ZrO2-33％（质量分数），ZrW2O8复合材料的热膨胀系数近似为零，但致密度不高；添加0．30％（质量分数）Al2O3有效地提高了ZrO2-33％（质量分数）ZrW2O8复合材料的致密度，与出现的新相Al2（WO4）3有关，而且对其零膨胀特性影响不大。     

高聚合度高醇解度聚乙烯醇的制备工艺研究

本文用氧化还原引发体系和复合乳化荆进行了乙酸乙烯酯（VAC）的乳液聚合，再在碱性甲醇溶液中对聚乙酸乙烯酯进行醇解制得高聚合度高醇解度聚乙烯辞（PVA）。实验结果表明制备高聚合度高醇解度聚乙烯醇的最佳工艺条件为：乳液聚合中聚合温度70℃、引发剂用量0．1％、复合乳化剂的组成2：2时所得产品的聚合度较高；醇解过程中，水洛温度25％、碱溶液的溶度在8％左右时产品的醇解度较高。     

组织工程海藻酸钙多孔支架的制备和研究

采用浇铸/冷冻干燥的方法制备出一种可组装于神经导管内的组织工程海藻酸钙多孔支架.通过IR、SEM、不同浓度交联剂对凝胶化过程的平衡溶胀比、抗压强度以及多孔支架在SBF液中的含水率和体积膨胀度的分析,对7海藻酸钙多孔支架的性能进行了讨论.结果表明,海藻酸钠多孔支架在氯化钙溶液浸渍中能快速反应生成海藻酸钙,并在凝胶化反应过程中可保持原有呈一定方向排列、孔隙连通和层状的多孔结构;多孔支架随交联剂中Ca2+浓度的增加,形成的海藻酸钙多孔支架的抗压强度提高,使支架的稳定性增加;海藻酸钙多孔支架在SBF中的含水率>90%,体积的膨胀度与交联剂中Ca2+浓度成反比.     

Sodium alginate/poly(vinyl alcohol) alloy membranes for the pervaporation, vapour permeation and vapour permeation with temperature difference separation of dimethylformamide/water mixtures: A comparative study

In this study, sodium alginate (NaAlg)/poly(vinyl alcohol) (PVA) membranes were prepared for the separation of dimethylformamide (DMF)/water mixtures. The two polymer components were independently crosslinked chemically with glutaraldehyde. The crosslinked membranes were characterized by fourier transform infrared spectrometry (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). The permeation and separation characteristics of water/DMF mixtures were investigated using the vacuum processes pervaporation (PV), vapour permeation (VP) and vapour permeation with temperature difference (TDVP) methods. The effects of NaAlg/PVA ratio, membrane thickness, operating temperature and temperature of the membrane surroundings, feed concentration on the transmembrane permeation rate and separation factor were investigated. Optimum NaAlg/PVA ratio was determined as 80/20 (w/w) for the separation. The permeation rate in VP was lower than those in PV, whereas the separation factors were higher. The activation energies of permeation in PV and VP were calculated to be 5.070 and 2.229 kcal/mol, respectively, for a 20 wt% of DMF solution.     

类产碱假单胞菌对不同型号PVA的降解特性研究

对类产碱假单胞菌降解不同型号PVA(0588,1788,2088,1750,1799)的降解效果及降解特性进行了研究。采用UV2900紫外分光光度计测吸光度法测定了各型号PVA的降解率,同时研究了PVA的分子量和醇解度、PVA浓度、接种菌种浓度、摇瓶转速等对PVA降解率的影响。结果表明:醇解度一定时,高聚合度PVA的降解效率远低于低聚合度PVA;而聚合度一定时,醇解度对降解率的影响不明显。在培养温度为30℃,培养时间为72 h,摇瓶转速为180 rad/min,PVA的质量浓度为0.5 g/L,接种菌的体积分数为4.0%时,PVA的降解率可达90.15%。     

Novel sodium alginate composite membranes prepared by incorporating cobalt(III) complex particles used in pervaporation separation of water–acetic acid mixtures at different temperatures

The present paper is our continuing effort to develop a new type of sodium alginate (NaAlg) composite membrane by incorporating cobalt(III)(3-acetylpyridine-o-aminobenzoylhydrazone) (Co-APABZ) complex as filler particles in different ratios. Membranes were prepared by solution casting followed by solvent evaporation and crosslinked with glutaraldehyde. Pervaporation (PV) performance of the prepared composite membranes was assessed in terms of flux and selectivity and these data were compared with the pristine NaAlg membrane in PV dehydration of water–acetic acid mixtures. Pristine Co-APABZ particles in crystalline form were prepared and characterized by the solid state X-ray diffraction (XRD) technique, while the NaAlg/Co(III)composite membranes were characterized by thermogravimetry (TGA) and dynamic mechanical thermal analyzer (DMTA). X-ray crystal structure of Co-APABZ has shown that the complex formed was crystalline in nature with six lattice water molecules, which are interconnected by hydrogen bonds linking together to form cyclic hexamers that are analogous to cyclohexane, creating water channels for an easy transport of water molecules. TGA indicated no changes in thermal stability of the membranes due to the presence of Co-APABZ in the NaAlg matrix. DMTA confirmed NaAlg crosslinking with glutaraldehyde. Effects of Co-APABZ content, membrane thickness, temperature and feed water compositions on membrane performance were investigated to find an optimum PV performance of the membranes developed. NaAlg composite membranes in the presence of Co-APABZ particles preferentially absorbed water molecules to facilitate diffusion of water through the membranes and thus enhance the selectivity to water. However, the amount of Co-APABZ present in the NaAlg matrix and the degree of membrane swelling has an effect on membrane performance. Selectivity of 174 for water with a flux of 0.123 kg/m² h was obtained for 5 wt.% Co-APABZ containing NaAlg matrix, when tested for the feed mixture containing 10 wt % water. The present results are superior to the previously published data based on NaAlg membranes. This article is CEPS communication #110.     

不同条件对PVA/CS复合水凝胶溶胀性能的影响

以聚乙烯醇(PVA)、壳聚糖(CS)为原料,戊二醛为交联剂,制备出PVA/CS复合水凝胶载体材料,改变PVA/CS的质量配比、交联剂含量、pH值和温度,考察了不同条件下对复合水凝胶溶胀性能的影响.结果表明,当PVA/CS质量比为3:1、交联剂体积分数为4%时所合成凝胶的溶胀性能较好;随着温度的升高,溶胀度不断减小;凝胶在酸性条件的溶胀性能远远优于碱性条件的溶胀性能.     

强疏水性AS-15色谱柱测定茶叶中F-、Cl-、NO3-、PO4（3-）、SO4（2-）、BrO3-、Br-、NO2-的研究

建立了一种利用强疏水性分离柱,通过KOH梯度淋洗,同时测定茶叶中F-、Cl-、NO3-、PO43-、SO42-、BrO3-、Br-、NO2-的方法。采用沸水冲泡茶样,茶水比为1：50,时间为5 min,过滤后稳定30 min待测;样液经过活性炭净化,再用0.20μm滤膜过滤后待测。结果表明：8种无机阴离子色谱峰能达到完全的基线分离,且浓度与峰面积呈良好的线性关系,检出限均低于0.056mg/L,加标回收率为96.5%~105.1%,该法用于茶样中8种无机阴离子含量的测定,结果稳定且重复性较好。     

高效液相色谱-串联质谱法测定贻贝中腹泻性贝类毒素的含量

采用液相色谱-串联质谱法检测了贻贝中大田软海绵酸(OA)和鳍藻毒素-1(DTX-1)两种腹泻性贝类毒素的含量。样品经80%甲醇水溶液提取,Sep-pak silica固相萃取小柱净化,80%甲醇水溶液定容后供HPLC-MS/MS分析。采用电喷雾负离子模式多反应监测方式进行检测,OA和DTX-1的定量检测的离子对分别为m/z 803.5/255.1和m/z817.4/255.1。2种贝类毒素在20~800μg/L范围内线性良好;在4个添加水平下OA的回收率为79.5%～88.6%,RSD为8.43%～10.4%;DTX-1的回收率为83.8%～91.2%,RSD为4.22%～6.54%。方法灵敏度高,定量限为0.02mg/kg。来自市场和产地的45个贻贝样品残留分析发现,有4个样品检出腹泻性贝类毒素,检出率为8.9%。     

ZnO含量对熔融法制备PbSe量子点玻璃的影响

采用高温熔融－退火法在钠硼铝硅酸盐（SiO2-B2O3-Na2O-Al2O3-ZnO-AIF3-Na2O）玻璃中生长了PbSe量子点,通过X射线衍射（XRD）、透射电镜（TEM）、光致荧光（PL）谱等研究了玻璃配料中不同ZnO含量对PbSe量子点尺寸和浓度的影响,结果表明,ZnO含量占总玻璃配料质量比约9．4％时,生成的量子点尺寸比较均匀,直径约为6．5nm,且浓度较高,PL谱强度最强,辐射峰位于1790nm,FWHM为296nm。玻璃配料中加入适量的ZnO有助于PbSe量子点的形成,减少Se元素的挥发,使玻璃中的量子点尺寸分布趋于均-化。     

不同厂家川芎配方颗粒中阿魏酸含量的比较

目的:考察不同厂家川芎配方颗粒中阿魏酸的含量。方法:采用高效液相色谱法。色谱柱:Diamonsil C18柱(4.6 mm×250 mm,5μm);流动相:乙腈-1%冰醋酸(20:80,V/V);流速:1.0 mL·min-1;检测波长:320nm;柱温:30℃,进样量为10μL。结果:阿魏酸在14 ng~280 ng范围内线性关系良好(r=0.9999),平均回收率为99.71%(RSD=2.06,n=5)。不同厂家川芎配方颗粒中阿魏酸的含量为0.05~0.32 mg·g-1。结论:不同厂家产品中阿魏酸的含量差异显著。     

高性能改性聚乙烯醇薄膜的制备及性能表征

作为可生物降解型的聚乙烯醇薄膜,其环保特性已得到了全世界的广泛承认,但是由于聚乙烯醇分子中含有大量的亲水性基团,导致成膜的耐水性差,这很大程度上限制了它的推广和应用。通过采用戊二醛、尿素对聚乙烯醇进行缩醛交联,并通过添加不同种类的增塑剂(丙三醇、PEG-400、MgCl2)破坏PVA的氢键作用,降低其结晶度,从而达到增塑改性效果,最后通过红外光谱FTIR、热重TG分析、物理机械性能以及接触角来鉴定物质的结构以及对其性能进行表征。结果表明:通过戊二醛、尿素与PVA羟基缩醛交联反应可以提高PVA成膜的耐水性能和热稳定性能,丙三醇、PEG-400、MgCl2等可以提高PVA的断裂伸长率和拉伸强度,当涂膜中交联剂戊二醛4%、尿素0.5%,增塑剂丙三醇4%、PEG-400为6%、MgCl2为2%时,成膜的机械性能最优,断裂伸长率达136.7%,拉伸强度达3.48MPa。     

Sorption, diffusion, and pervaporation characteristics of dimethylformamide/water mixtures using sodium alginate/polyvinyl pyrrolidone blend membranes

Separation of aqueous dimethylformamide (DMF) solutions in the concentration range of 0-100 wt% were studied using sodium alginate (NaAlg)/polyvinyl pyrrolidone (PVP) blend membranes. The NaAlg was blended in different ratios with PVP. Prepared membranes were crosslinked with CaCl₂ for testing in pervaporation (PV) separation of DMF/water mixtures. Effects of feed composition (0-100 wt%), operating temperature (30-50 °C), and membrane thickness were investigated. Best results were obtained at the conditions of 75/25 NaAlg/PVP blend ratio (w/w), 40 °C temperature, 20 wt% DMF concentration, and 70 μm membrane thickness. Blending of PVP with NaAlg increased permeation flux whereas it decreased the separation factor. NaAlg/PVP membranes gave separation factors of 5.5-27 for permeation flux of 0.96-1.81 kg/m²h depending on the operating temperature and the feed mixture composition. Arrhenius plot of permeation flux data versus reciprocal of temperature exhibited linear trends. Permeation activation energy of DMF and water in the PV was calculated as 6.76 and 1.88 kcal/mol, respectively, using an Arrhenius type relationship. Sorption-diffusion properties of the NaAlg/PVP membranes were also investigated at the operating temperature and the feed composition.