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细胞对硅橡胶复合膜渗透蒸发分离性能的影响 总被引:4,自引:0,他引:4
利用自制的硅橡胶复合膜对乙醇-水模型溶液、含有干酵母的乙醇-水模型溶液、以及实际发酵液进行渗透蒸发分离乙醇实验,研究了细胞对膜性能的影响、结果表明:与纯乙醇模型溶液的分离相比,膜对含有干酵母的乙醇-水模型溶液、真实发酵液的分离表现出更好的性能,显示细胞的存在和活动对膜传质有一定的促进作用.连续发酵过程中,在一定的细胞浓度下(10g/L),硅橡胶膜维持了长期稳定的分离性能;产品乙醇的有效分离降低了其对酵母细胞的抑制作用,使沉积在膜面上的细胞层促进了膜的分离性能;但提高细胞浓度(15g/L)后却因更厚的细胞层的堆积造成膜面传递状况劣化,使膜性能下降.因此发酵液中的细胞浓度、膜面上的细胞沉积以及膜性能之间存在一种最佳的相互促进和搭配关系. 相似文献
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采用粒子填充的聚丙烯腈(PAN)作为基膜材料,纺制成了中空纤维,对基膜进行拉伸,热定型等后处理,并在此基础上研制了壳聚/聚丙烯腈中空纤维复合膜,考察了基膜的改性及不同操作条件对复合膜分离性能的影响,发现采用该基膜制备的复合膜对乙醇-水体系具有很好的分离性能。 相似文献
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聚丙烯酸钠复合超滤膜研制初探(I)UPANA—l复合膜的制备 总被引:2,自引:1,他引:1
以聚丙烯酸钠为复合膜分离层材料,多孔的聚醚砜(PES)超滤膜为基膜研制出具有超薄分离层的聚丙烯酸钠复合超滤膜(UPANA-1).用浓度为0.005 g/L的分子量为1 000的聚乙二醇水溶液作为介质溶液,室温、压力0.6 MPa下做膜性能测试,UPANA-1膜的截留率大于90%,水通量为32.6 L/(m2*h).并着重研究了基膜的选择、超薄分离层膜液的组成等制膜条件对复合膜性能的影响. 相似文献
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以聚丙烯酸钠为复合膜分离层材料,多孔的聚醚砜(PES)超滤膜为基膜研制出具有超薄分离层的聚丙烯酸钠复合超滤膜(UPANA-1).用浓度为0.005 g/L的分子量为1 000的聚乙二醇水溶液作为介质溶液,室温、压力0.6 MPa下做膜性能测试,UPANA-1膜的截留率大于90%,水通量为32.6 L/(m2*h).并着重研究了基膜的选择、超薄分离层膜液的组成等制膜条件对复合膜性能的影响. 相似文献
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壳聚糖膜渗透汽化传递行为的研究 总被引:3,自引:3,他引:0
以壳聚糖膜及硫酸交联壳聚糖膜为基础、以乙醇-水体系为研究对象,考察了浓度、温度、交联对壳聚糖膜以及硫酸交联壳聚糖膜的传递行为的影响。实验结果表明,对壳聚膜糖膜和和硫酸交联壳聚糖膜来说,渗透通量与分离性能强烈地取决于原料组成。组发在膜内溶胀分配关系随原料浓度的改变而改变,这种溶胀过程的热力学分配关系直接支配着渗透气化的分离性能。随着温度的上升,乙醇与水的渗透通量急剧增加,而溶胀度变化不大。表明在一定 相似文献
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聚酰亚胺/磺化聚芳醚砜共混中空纤维膜用于醇/醚气相分离的研究 总被引:2,自引:1,他引:1
甲醇/ 甲基叔丁基醚的分离是目前具有实用意义的重要研究课题之一.文中采用气流吹扫式操作,研究了不同共混比的磺化聚芳醚砜/ 聚酰亚胺中空纤维膜对甲醇/ 甲基叔丁基醚气相混合体系的分离性能,以及不同操作条件对分离性能的影响.结果表明,共混改性聚酰亚胺膜具有非常高的醇/ 醚分离系数,有很好的应用前景. 相似文献
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分离有机物/水混合物的聚丙烯酸膜研究进展 总被引:4,自引:1,他引:3
介绍了聚丙烯酸(PAA)的不同类型分离膜的制备工艺,及在有机物/水混合物中的渗透汽化(PV)分离性能,重点讨论了交联剂浓度、高分子网络结构、支撑膜和共混膜性能对膜分离性能的影响,简要分析了操作参数如料液浓度、操作温度等影响因素,并提出了PAA膜在今后研究开发中的方向, 相似文献
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首先在丝素(SF)溶液中添加既定浓度的海藻酸钠(SA)溶液和一定体积的75%甘油、50%戊二醛以及模型药物罗丹明B(4g/L),将均匀混合液以浇铸方法制备丝素/海藻酸钠(SF/SA)膜模型药物缓释敷料;然后利用响应曲面法筛选最佳韧性(以断裂伸长率表示)SF/SA膜的制备参数;最后对优化膜的韧性和药物释放动力学模型进行检验与分析。实验得出,在浓度为2.5%的丝素溶液中,添加等体积0.96%浓度的海藻酸钠溶液,且甘油和戊二醛添加量分别为膜液总体积1.41%和4.47%时达到最优制备条件,此时膜的断裂伸长率为228.36%。检验结果显示相对对照组,优化组的断裂伸长率扩大了18.14倍;根据回归方程计算得出影响断裂伸长率的主效因素是甘油,且其与戊二醛具有显著协同作用。另外,根据优化组的释药结果分析表明:该体系具有药物缓释功效,释药动力学归属于Fickan模型。以上结果有利于丝素/海藻酸钠膜舒适型药物缓释敷料的制备,可为该生物材料的应用研究提供参考。 相似文献
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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. 相似文献
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Ueyama Y Koyama T Ishikawa K Mano T Ogawa Y Nagatsuka H Suzuki K 《Journal of materials science. Materials in medicine》2006,17(3):281-288
In order to understand the requirements of guided bone regeneration (GBR) involving alginate base self-setting barrier membranes,
GBR was performed in the case of bicortical bone defects formed at the tibiae of experimental animals employing self-setting
and ready-made alginate membranes. Connective tissue ingress into the bone defects at the skin side of the tibia was observed
when GBR was generated utilizing ready-made alginate membrane. In contrast, bone defects were reconstructed with bone tissue
when GBR was generated with self-setting alginate membrane formed from aqueous 3% sodium alginate and 3% CaCl2 solutions. The unreacted aqueous sodium alginate solution inherent to self-setting alginate membrane did not inhibit bone
tissue regeneration. Rather, callus bone was formed using sodium alginate as the nucleus. However, when GBR was effected with
self-setting alginate membrane formed from aqueous 10% CaCl2 solution, membrane was too thick and thus regeneration of bone tissue in the bone cavity was prevented. Therefore, we concluded
that self-setting alginate membrane is very useful as a barrier membrane for GBR upon appropriate adjustment of conditions
with respect to preparation of alginate membrane. 相似文献
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分别采用冷冻干燥法和自然晾干法制备海藻酸钙膜材料,考察比较了两种海藻酸钙膜材料的形貌及吸水性能。海藻酸钙自然晾干膜为无色透明膜,冻干膜为白色海绵膜,且冻干膜与晾干膜相比具有开放、贯通的多孔结构,其孔径介于100μm~200μm之间。海藻酸钠质量百分比含量为2%时,晾干膜和冻干膜对蒸馏水的吸水率分别为78.7%和985.0%,经3500r/min离心3min后保水率分别为42.5%和81.8%,两膜材料均具有较好的重复使用性能,其中反复吸水-放水4次后冻干膜的吸水率仍高达869.4%。 相似文献
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以聚砜(PS)超滤膜为基膜,海藻酸钠(Sodium Alginate,NaAlg)和均苯三甲酰氯(TMC)分别为水相和油相反应单体,经界面聚合反应制备一种新型复合纳滤膜.研究了制备影响因素对复合膜分离性能的影响,并利用扫描电镜(SEM)对复合膜的表面形态和断面结构进行了表征.结果表明,当海藻酸钠的质量分数为2.0%,TMC的质量分数为0.25%,TMC反应时间为30s,热处理温度为50℃,热处理时间为10min时所制备的膜性能最好.所制备的复合纳滤膜在操作压力1.0MPa下,对1 000mg/L的Na2SO4溶液的脱盐率为84.9%,通量为12.2L/(m2.h). 相似文献
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Yeung Keun Choi Fakhar ud Din Dong Wuk Kim Yong-Il Kim Jong Oh Kim Sae Kwang Ku 《Drug development and industrial pharmacy》2014,40(7):852-859
The conservative single-layered wound dressing system is decomposed when mixed in polyvinyl alcohol (PVA) solution, which means it cannot be used with a temperature-sensitive drug. The goal of this investigation was to make an amniotic membrane extract (AME)-loaded double-layered wound dressing with an improved healing result compared to the conservative single-layered wound dressing systems. The double-layered wound dressing was developed with PVA/sodium alginate using a freeze–melting technique; one layer was PVA layer and the other was the drug-loaded sodium alginate layer. Its gel properties were assessed compared to single-layered wound dressings. Moreover, in vivo wound-healing effects and histopathology were calculated compared to commercial products. The double-layered wound dressing gave a similar gel fraction and Young’s module as single-layered wound bandages developed with only PVA, and a similar inflammation ability and WVTR as single-layered wound dressings developed with PVA and sodium alginate. Our data indicate that these double-layered wound bandages were just as swellable, but more elastic and stronger than single-layered wound dressings comprised of the same polymers and quantities, possibly giving an acceptable level of moisture and accumulation of exudates in the wound zone. Compared to the commercial product, the double-layered wound dressing comprising 6.7% PVA, 0.5% sodium alginate and 0.01% AME significantly enhanced the wound-healing effect in the wound-healing test. Histological investigations showed that superior full-thickness wound-healing effects compared to the commercial product. Therefore, the double-layered wound dressing would be an outstanding wound-dressing system with improved wound healing and good gel property. 相似文献
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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. 相似文献
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为了提高海藻酸钠与明胶各自的性能,首先,以海藻酸钠和明胶为原料,以京尼平、CaCl2为交联剂,采用分步交联法制备了明胶/海藻酸钠互穿网络膜。然后,利用FTIR对明胶/海藻酸钠互穿网络结构进行了表征与分析,根据FTIR结果推测了互穿网络结构形成的机制。最后,探讨了京尼平的加入量和明胶与京尼平的质量比对互穿网络膜力学性能和交联度的影响,及海藻酸钠与明胶的质量比对互穿网络膜力学性能、断面形貌、热稳定性和吸水保水性能的影响。结果表明:当明胶与京尼平的质量比为200∶1、海藻酸钠与明胶的质量比为2∶1时,互穿网络膜具有最佳的力学性能、吸水保水性能和相容性;此外,互穿网络膜的力学性能也优于纯海藻酸钠膜与纯明胶膜的。明胶的加入提高了互穿网络膜在低温区的热稳定性,但降低了高温区的热稳定性。海藻酸钠与明胶之间可能以分子间作用力、氢键及离子键等相互作用,提高了二者各自的初始分解温度与最大热分解温度。研究解决了海藻酸钠与明胶力学性能差的问题,为拓展海藻酸钠在医用领域的应用提供参考。 相似文献