芘磺酸型磺化聚砜质子交换膜的性能研究

利用聚砜(PS)制备氯代酰基化聚砜(CPS),并与8-羟基-1,3,6-芘三磺酸三钠(HBS)小分子试剂通过亲核取代反应制备磺酸基团键合量不同的芘磺酸型磺化聚砜PS-BS。通过流延成膜法制备相应质子交换膜,考察温度对其吸水率、吸水溶胀性、质子传导率等性能的影响。结果表明,由于侧链末端磺酸基团运动能力随温度升高而增强,相应质子膜的性能也随温度升高呈现正增长,其中磺酸键合量为1.51 mmol/g的PS-BS-4膜在25℃和85℃的吸水率分别为29.6%和42.1%,相应的吸水溶胀性仅为9.4%和24.3%,而PS-BS-4膜在85℃的质子传导率达到0.147 S/cm,非常接近商业化Nafion115膜的性能。     

硬脂酸改性γ-Al_2O_3填充PEBAX膜渗透汽化分离苯胺

利用硬脂酸对纳米γ-Al_2O_3改性,分别制备了聚醚共聚酰胺(PEBAX)均质膜、填充膜、复合膜以及填充型复合膜四种分离膜,探讨了膜在苯胺/正庚烷体系中的溶胀性能和渗透汽化性能。利用FT-IR、XRD分别考察了改性前后γ-Al_2O_3颗粒官能团和晶体结构的变化情况,通过SEM观察膜的形貌结构。溶胀实验结果表明:随着料液中苯胺浓度和料液温度的升高,溶胀度均持续增大,在48 h时达到溶胀平衡,填充量为2%(wt)时填充膜的溶胀效果最好;渗透汽化实验结果表明:膜的渗透通量和分离因子均随料液中苯胺浓度和料液温度的升高而持续增大,填充型复合膜的综合性能最优,其填充量为2%(wt)时分离性能最佳,当苯胺浓度为5000μg×g~(-1)、温度为70℃时,膜的渗透总通量为5.64 kg×m~(-2)×h~(-1),分离因子为3.07。     

聚醚共聚酰胺(PEBA)膜的溶胀和渗透汽化行为研究

用涂布法制备出PEBA均质膜,分别测试了膜在纯醋酸正丁酯、水以及醋酸正丁酯稀水溶液中的溶胀率,并考察了浸泡时间、温度和溶液浓度对溶胀率的影响;结果表明:PEBA膜在水中溶胀很小,对醋酸正丁酯具有优先吸附能力;溶胀率随浸泡时间的延长、浸泡液浓度和温度的升高而逐渐上升。渗透汽化实验表明膜对醋酸正丁酯的良好选择性,膜的渗透通量和分离因子随着浓度的增加而增加,渗透通量随着温度的升高而增加,但分离因子随温度的升高而减小;当原料液浓度为0.6%(wt)时,醋酸正丁酯的渗透通量为143.9g·m-2·h-1,分离因子达到236.9。     

季铵化聚醚砜氢氧根离子交换膜的制备及研究

以氯甲基辛基醚(CMOE)为氯甲基化试剂,成功制备了不同取代度的氯甲基化聚醚砜(CMPES),使用三甲胺水溶液将CMPES膜季铵化,制备出季铵化聚醚砜氢氧根离子(QAPESOH)交换膜。对膜的离子交换容量、吸水率、溶胀度以及离子传导率进行测试,结果表明,当QAPESOH膜的氯甲基化程度(DC)在23%～51%时,即使温度升高到60℃,膜都具有良好的吸水率和适当的溶胀度。特别是DC为51%的膜,其氢氧根传导率在20℃时可以达到15.6mS/cm,并且具有良好的机械稳定性,说明QAPESOH膜在氢氧根离子交换膜燃料电池方面有很好的应用前景。     

聚乙烯醇-羟乙基纤维素共混膜的制备及性能

以羟乙基纤维素(HEC)和聚乙烯醇(PVA)为原料,通过溶液浇铸共混制备不同含量的羟乙基纤维素/聚乙烯醇(HEC/PVA)共混膜,用傅立叶红外分析(FT-IR)、扫描电子显微镜(SEM)进行表征,并考察了HEC/PVA膜的力学性能.结果表明:当PVA质量含量为40％时,共混膜的力学性能较纯HEC有显著提高;温度越低膜的溶胀度越小,但当温度升到60℃以后,膜的溶胀度几乎不变化,说明膜在高温下尺寸的稳定性很好;随着温度的升高,膜的含水率不断增加,制备的共混膜的使用温度不要超过80℃.     

耐溶剂聚酰亚胺膜渗透汽化分离有机溶剂的研究

文章制备了聚酰亚胺渗透汽化膜,并将其用于乙酸和N,N-二甲基乙酰胺(DMAc)脱水。实验结果表明:聚酰亚胺渗透汽化膜能有效地从乙酸和DMAc中脱除水,对于含水量为2.20 wt%的乙酸水溶液,其渗透通量为27.7 g/(m2h),分离因子为3427,溶胀度为17.7%;对于含水量为6.63 wt%的DMAc水溶液,其渗透通量为4.50 g/(m2h),透过液中无DMAc,溶胀度为36.3%。同时,随着乙酸和DMAc水溶液温度的升高,其渗透通量均增大,在乙酸体系中分离因子减小。     

CTAB改性膨润土填充PEBAX/PVDF膜渗透汽化降低汽油噻吩含量

用十六烷基三甲基溴化铵(CTAB)对膨润土进行柱撑改性,并对改性前后的膨润土进行吸附实验及红外测定。将改性后膨润土置于填充聚醚共聚乙酰胺(PEBAX)聚合物溶液中,以聚偏氟乙烯(PVDF)超滤膜为支撑膜,制备复合膜,考察复合膜在模拟汽油(噻吩/正庚烷)中的溶胀性能,并进行渗透汽化实验,研究膜的分离性能。利用SEM考察膜的形貌结构。结果发现:30℃下,溶胀度随噻吩质量分数的增加而升高,15 min后达溶胀平衡,并且在填充量为20%时最大。渗透汽化结果表明:在料液温度为30℃,噻吩质量分数为1 100μg/g时,CTAB填充量为20%的PEBAX/PVDF复合膜的渗透通量和硫富集因子分别为2.81 kg/(m2·h)和4.65。     

炭黑改性质子交换膜的制备及其性能研究

制备Nafion膜(M1)和添加炭黑的改性Nafion膜(M2),探索成膜的工艺条件,比较了膜改性前后含水率、溶胀度和阻挡OH-能力等性质,并将改性前后的Nafion膜应用于微生物燃料电池的质子交换膜,比较其产电性能。结果表明:适宜成膜温度为180℃、刮膜温度为40~50℃;与Nafion膜相比,加炭黑0.5%的Nafion膜的含水率增加、溶胀度降低、阻碍OH-能力增强;电池性能试验表明采用炭黑改性质子交换膜的电池内阻减小11%、功率密度增加15%,对应电池的产电性能优于不加炭黑的Nafion膜。     

光交联PVA-SBQ/透明质酸纳米纤维的制备及性能

为了增强透明质酸的耐水溶性、实现药物缓释,本研究应用静电纺技术制备改性透明质酸（GMHA）与聚乙烯醇-苯乙烯吡啶（PVA-SBQ）的复合纳米纤维膜,进一步在紫外光照射下得到光交联复合纤维膜。系统研究了不同的紫外光照时间、温度和pH值下复合纳米纤维的溶胀比以及载药释放性能,结果表明复合纳米纤维膜的溶胀比随温度升高而减小,随pH值升高而增大。光交联之后的1.0%（质量分数,下同）载药复合纳米纤维膜在10 h内的累积释放率在40%左右,释放曲线比较平缓,达到药物缓释的目的。     

疏水SiO_2填充PDMS膜分离水中乙酸正丁酯的性能

以聚偏氟乙烯(PVDF)为支撑层,选用疏水性纳米SiO_2粉体作为改性剂,制备出聚二甲基硅氧烷(PDMS)复合膜材料,并用于乙酸正丁酯/水溶液的渗透汽化分离。采用SEM、FTIR、XRD、拉伸实验、接触角及正电子湮没寿命谱测定等对膜材料物理化学性能进行了表征,考察了膜材料的溶胀行为及渗透汽化性能。结果表明,SiO_2在PDMS膜中分散均匀,且没有发生化学作用,并提高了膜材料的机械强度和疏水性。随着SiO_2添加量增加,膜在乙酸正丁酯溶液中的溶胀度先升后降,渗透通量呈下降趋势,而分离因子先增大后减小。当SiO_2添加量为4%(质量)时,随进料浓度的增加,渗透通量增大,分离因子先增大后减小;随着温度升高,渗透通量增大,分离因子减小;渗透通量和分离因子最大值分别为240 g·m~(-2)·h~(-1)和542。     

聚乙烯醇缓释膜缓释性能的初步研究

采用部分醇解级和完全醇解级的聚乙烯醇(PVA)混合物制备了PVA缓释膜,研究了缓释膜的缓释机理。以I(1788)含量的增大,缓释膜的缓释速率逐渐增大;缓释膜的厚度越小,其缓释速率越大;当PVA BM-I(1788)蒸馏水为载体,初步测定了PVA缓释膜的透水速率。探讨了PVA缓释膜缓释速率的影响因素,测定了PVA缓释膜的溶胀率以及溶解失重率,并对其稳定性进行了初步研究。结果表明:随着部分醇解级PVA BM-含量为30%时,缓释膜的溶胀率达到最大;缓释膜的稳定性良好,能够较长时间保持其缓释性能。     

原位生成PNaAA/EPDM吸水膨胀橡胶的吸水膨胀性能研究

采用原位生成法制备聚丙烯酸钠(PNaAA)／EPDM吸水膨胀橡胶，研究其吸水膨胀性能的影响因素。结果表明，过氧化二异丙苯用量增大，硫化胶的吸水膨胀性能降低，NaAA理论生成量增大，硫化胶的吸水膨胀性能提高，氢氧化钠／AA摩尔比为1～1．2时，硫化胶的吸水膨胀性能较好，水溶液温度高，硫化胶的吸水膨胀率较大，水溶液中Na^ 含量越大，硫化胶(尤其是NaAA理论生成量大时)的吸水膨胀率越小。     

类氨基酸基载药水凝胶敷料的制备与性能

为制备一种具有良好生物相容性、可控缓释的物理交联的水凝胶敷料,选用类氨基酸单体N-丙烯酰基甘氨酰胺（NAGA）与生物发酵产物衣康酸（IA）为单体,在紫外光条件下,通过自由基聚合,在不需要外加任何交联剂条件下即可形成水凝胶聚（N-丙烯酰基甘氨酰胺-衣康酸）（P(NAGA-IA)）。所得水凝胶具有溶胶-凝胶转变温度（UCST）、较高的水溶胀率（40倍）及力学性能（压缩模量最高540 kPa）、较优的药物负载性和缓释性,这是因为NAGA单元提供分子间多重氢键作用,进而赋予了水凝胶较优的综合性能;而IA单元赋予了聚合物的pH刺激响应性,从而可诱导药物的释放。因此,所得P (NAGA-IA)水凝胶可作敷料用于创伤治疗。     

Indomethacin release behaviors from pH and thermoresponsive poly(vinyl alcohol) and poly(acrylic acid) IPN hydrogels for site-specific drug delivery

A temperature- and pH-responsive drug delivery system was studied by using interpenetrating polymer network (IPN) hydrogels constructed with poly(acrylic acid) (PAAc) and poly(vinyl alcohol) (PVA). The release of indomethacin incorporated into these hydrogels showed pulsatile patterns in response to both pH and temperature. Indomethacin diffused from the polymer matrices through the swelling and deswelling mechanism. The release amount increased at higher temperature because of the swelling caused by the dissociation of hydrogen bonding. The drastic change of drug release was achieved by alternating pH of the buffer solution and was attributed to the change of states of ionic groups within IPN hydrogels. The free water contents were calculated by using differential scanning calorimetry (DSC), and were proved to be the main factor in the swelling. These results demonstrated that the drug release could be controlled by the swelling/deswelling degree of IPN hydrogels as functions of pH and/or temperature. © 1997 John Wiley & Sons, Inc. J Appl Polm Sci 65: 685–693     

黏结煤与不黏煤共热解特性研究

为了利用内构件反应器热解技术实现黏结性煤的高值化利用,采用TG-MS和固定床反应器研究了黏结的山西兴县煤(简称XX煤)与不黏的先锋褐煤(简称XF煤)共热解时的破黏和热解特性。TG-MS实验结果表明,XX煤与XF煤配制的混合煤比XX煤黏性小,且XF煤促进了XX煤热解,混合煤热解行为是两种煤共同作用的结果。固定床热解实验表明,煤粒径越小,降黏越显著;XX煤和XF煤的比例(XX:XF)越小,降黏越显著,XX:XF小于5:5时,可消除结焦团块;XX:XF越小,半焦产率越低,焦油和煤气产率越高;随XX:XF减小,焦油中<170℃和230~300℃的馏分含量先升后降,XX:XF=6:4~3:7时最高,170~210℃、210~230℃和300~360℃的馏分逐渐增加,>360℃的馏分含量不断降低;随XX:XF的减小,H2含量先升高后降低,在XX:XF=3:7时最高;CO含量呈略微升高趋势;CO2含量先逐步升高,在XX:XF=6:4达到最高,然后从XX:XF=5:5开始降低,在XX:XF=3:7达到最低,然后又开始升高;CH4及C2~C3组分含量呈下降趋势,而H2+CO+CH4 (煤气中有效组分之和)的含量先下降再升高接着再降低,在XX:XF=6:4时最低,XX:XF=3:7时最高。XX:XF越小,虽半焦的C/N和C/H不断减少,但C元素含量增幅和N, H元素含量减幅增大;比表面积越大,内孔结构越多越大,起燃温度越低,燃烧越彻底。     

Swelling behavior of crosslinked hydroxypropylcellulose films retaining cholesteric liquid crystalline order,II. Effects of temperature,solvent, and pH

Crosslinked hydroxypropylcellulose (HPC) films were cast from the cholesteric liquid crystalline HPC solution in methanol. The films retained the cholesteric liquid crystalline order. The dependences of swelling behavior of our films in water and propanol on temperature and on pH of the solvent were determined. The response of our films to the changes in water, temperature and in pH was discussed. In water, the equilibrium swelling ratio (B_e) decreased with temperature whereas B_e increased with temperature in propanol. For a given composition of water and propanol, B_e was independent of temperature. B_e in the acidic solvents was higher than in the alkaline solvents. The response data to the stepwise change in temperature revealed that the deswelling behavior was more rapid than the swelling behavior in water, and the swelling-deswelling behavior was reversible. The response to the stepwise change in pH was almost the same as that of the change in temperature, but the surface of the film was attacked by the acid and became fluffy with increasing soaking time.     

Synthesis of biodegradable thermo- and pH-responsive hydrogels for controlled drug release

Novel intelligent hydrogels composed of biodegradable and pH-sensitive poly(l-glutamic acid) (PGA) and temperature sensitive poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) (PNH) were synthesized and characterized for controlled release of hydrophilic drug. The influence of pH on the equilibrium swelling ratios of the hydrogels was investigated. A higher PNH content resulted in lower equilibrium swelling ratios. Although temperature had little influence on the swelling behaviors of the hydrogels, the changes of optical transmittance of hydrogels as a function of temperature were marked, which showed that the PNH part of hydrogel exhibited hydrophobic property at temperature above the lower critical solution temperature (LCST). The biodegradation rate of the stimuli-sensitive hydrogels in the presence of enzyme was directly proportional to the PGA content. Lysozyme was chosen as a model drug and loaded into the hydrogels. The in vitro drug release experiment was carried out at different pH values and the release data suggested that both the pH and PNH content played important roles in the drug release behaviors of the hydrogels.     

Controlled release NPK compound fertilizer with the function of water retention

Controlled release nitrogen, phosphorus and potassium (CRNPK) compound fertilizer with the function of water retention was prepared, which possessed the core/shell structure. Its core was urea formaldehyde (UF) and polyphosphate potassium (PAK) fertilizer, and the shell was P(acrylic acid-co-acrylamide)/kaolin (P(AA-co-AM)/kaolin) superabsorbent composite. Analysis results showed that the N, P and K contents were 11.3, 21.1 (shown by P₂O₅) and 8.6 (shown by K₂O) wt%, respectively. The synthesis conditions of inversion suspension polymerization were studied systematically. The water absorbency of the product was 91 g/g in tap water. The swelling rate, slow release and water retention properties of CRNPK were also investigated. Additionally, the effect of temperature on the nutrients release behaviors was studied. The results showed that the product had high initial swelling rate, and the product not only had a good slow release property but also excellent water retention ability, which could effectively improve the utilization of fertilizer and water resource at the same time.     

莫西沙星/纳米纤维素缓释膜的制备及其释药性能研究

将2,2,6,6-四甲基哌啶-1-氧化物自由基（TEMPO）氧化纳米纤维素（NFC）与广谱抗菌剂莫西沙星通过物理共混、真空抽滤制备出具有缓释和抗菌特性的莫西沙星/NFC缓释膜。研究了NFC的羧基含量、制备NFC时的均质次数对莫西沙星/NFC缓释膜的力学性能、溶胀性能以及药物释放性能的影响,同时探究了缓释膜的抑菌效果。结果表明：当NFC含羧基为1.13 mmol/g,NFC制备时的均质次数为8次时,莫西沙星/NFC缓释膜的弹性模量为3.48 GPa,其平衡溶胀率比NFC膜高,可达到6.03,药物负载率为21%,在体外8 h释药量为19.96%。不同羧基含量的莫西沙星/NFC缓释膜的药物释放曲线均符合Peppas方程;均质次数和pH值增加时,缓释膜的药物释放由渗透和溶胀释放为主转为浓度差驱动的扩散释放为主,相应地其释放曲线由符合Higuchi方程转为符合Peppas方程。莫西沙星/NFC缓释膜对标准金黄色葡萄球菌的抑菌圈直径在4.38~6.33 mm范围内,有着明显的抗菌作用,含羧基1.70 mmol/g,均质次数8次的莫西沙星/NFC缓释膜抑菌效果最好。     

Preparation a core-shell lipid/polymer nanoparticle containing Isotretinoin drug with pH sensitive property: A response surface methodology study

In this study, a core-shell lipid/polymer nanoparticle (NP) was prepared to deliver Isotretinoin drug with pH sensitive and controllable drug release property for oral administration usage. Chitosan was cross-linked to tripolyphosphate to form the core of the NP using the ionic gelation technique and coated with glycerol monostearate lipid as a shell by applying a two-step approach. Response surface methodology was used to investigate the effects of various parameters on particle size and drug entrapment efficiency of the nanoparticles. Optimal nanoparticles with lower particle size and higher entrapment efficiency had a diameter of 100 nm based on TEM analysis and 64% drug entrapment efficiency. Coating NPs surface with lipid changed the NPs charge, hydrophilicity and swelling property. Lipid coating NPs changed release rate from 6 to 4% after 2 h in simulated gastric fluid (SGF), 9 to 16% after 6 h in simulated intestine fluid (SIF) and 21 to 71% after 7 days in blood medium. Kinetic modeling of drug release confirmed Fickian diffusion based on Higuchi model in SIF and blood media where swelling and dissolution of polymer network were negligible, while drug dissolution due to polymer swelling in SGF media was the dominant mechanism for drug release.