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1.
基于季戊四醇的二代硅碳烷液晶树状物--端基含36个丁氧基偶氮苯基团 总被引:1,自引:1,他引:1
以基于季戊四醇的二代硅碳烷树状氯化物PCSi-2G-Cl为脚手架、4一-丁氧基-4’-羟己氧基偶氮苯(M—C4)为介晶基元,合成了以季戊四醇为核、端基含36个丁氧基偶氮苯的新型硅碳烷液晶树状物PCSi-2GC4。利用红外光谱(IR)、核磁共振(^1H NMR)、元素分析(EA)、偏光显微镜(POM)和差示扫描量热法(DSC)进行了表征。PCSi-2G-C4与M—C4同为向列相,说明树状物相态由介晶基元相态决定。PCSi-2G-C4的熔点比M—C4降低13℃,清亮点比M—C4降低15℃。 相似文献
2.
丁酰壳聚糖树枝网络交联膜的制备及其固定酶的应用 总被引:6,自引:0,他引:6
通过丁酰壳聚糖与丙烯酰氧基丙基二甲氧基硅烷的迈克尔加成反应合成了含有甲氧硅烷基 (Methoxysilyl )的丁酰壳聚糖 (Mos butyrylchitosan) ,Mos基团通过水解缩合成树枝网络膜 (DBCSF)。SEM测定表明 ,该膜具有微孔结构。当丁酰壳聚糖树枝网络膜固定辣根过氧化酶 (HRP)修饰金电极表面 ,采用示差脉冲极谱 (DPV )方法对过氧化氢进行监测 ,测量限度可达到 2× 10 -10 mol/L ,传感器 4℃储存 2个月以后酶的活性可保持 75 %。 相似文献
3.
制备了基于季戊四醇外围含丁氧基/己氧基偶氮苯基团的新型硅碳烷液晶树状物.利用Williamson反应和偶氮反应合成了4-[4-(6-羟己氧基)苯基]丁氧基偶氮苯与4-[4-(6-羟己氧基)苯基]己氧基偶氮苯两种液晶基元.以基于季戊四醇端基为Si-Cl键的硅碳烷树状物为脚手架,分别以上述两种偶氮苯液晶基团对其表面进行修饰,得到两种树状液晶化合物.采用偏光显微镜(POM)和示差扫描量热法(DSC)对修饰单元和树状物的液晶性进行表征,表明其均示向列相. 相似文献
4.
PS/P(BA—BOA)核壳乳液的研究 总被引:2,自引:0,他引:2
以丁氧基甲基丙烯酰胺(BOA)为活性单体,采用种子乳液聚合法制备了PS/P(BA-BOA)核壳型复合乳液,用透射电子显微镜观察了乳液粒子的微观形态,探讨了聚合方式等对微观结构的影响,对乳液的稳定性以及乳液膜的力学性能进行了测试,考察了聚合方式对乳液性能的影响。 相似文献
5.
叔丁氧基钾/正丁基锂体系合成无规丁苯橡胶的结构与性能 总被引:3,自引:1,他引:2
采用叔丁氧基钾/正丁基锂为引发剂、合成出溶聚无规丁苯橡胶,用^13C-NMR、IR、GPC等对共聚物的序列分布及微观结构进行了表征。该体系合成的丁苯共聚具有均匀的分子内和分子间分布。采用偶联方式,可以改善生胶的冷流现象。并考察了该体系合成无规丁苯橡胶的加工性能、力学性能、抗湿滑性和滚动损失。 相似文献
6.
2,9,16,23-四-芳氧基酞菁镍的合成及光谱性质 总被引:2,自引:0,他引:2
用4-苯氧基邻苯二腈、4-(4-羟基-苯氧基)邻苯二腈、4-(β-萘氧基)邻苯二腈和无取代邻苯二腈分别和金属盐、尿素、钼酸铵在熔融状态下合成2,9,16,23-四-苯氧基金属酞菁、2,9,16,23-四-(4-羟基-苯氧基)金属酞菁和2,9,16,23-四-(β-萘氧基)金属酞菁以及无取代金属酞菁,对产物进行了IR、UV-vis光谱测定和表征,并对比3种化合物谱学性质.实验结果表明,对于芳氧基取代的金属酞菁来说,随着苯环数目和苯环上供电子基数目的增加,取代酞菁产生的红移程度都会变大. 相似文献
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γ-甲基丙烯酰氧基丙基三甲氧基硅烷改性丙烯酸酯乳液的研究 总被引:5,自引:1,他引:4
采用单体后滴加的方法,用γ-甲基丙烯酰氧基丙基三甲氧基硅烷改性丙烯酸酯乳液进行改性,通过乳液共聚合成了丙烯酸酯-有机硅共聚物,对合成工艺进行了初步探索,通过红外光谱,DSC分析对产物进行了表征,研究了不同有机硅含量对共聚产物力学性能,吸水率的影响,证实了丙烯酸酯-有机硅共聚物比纯丙烯酸酯具有更优良的力学性能和耐水性。 相似文献
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合成了外围含4-丁氧基偶氮苯介晶基元的三代硅碳烷液晶树状物PCSi-3G-C4.以4-[4-(6-羟基已氧基)苯基]丁氧基偶氮苯介晶基团对端基官能团为Si-Cl的三代硅碳烷树状物PCSi-3G-Cl脚手架进行功能化,并利用元素分析、红外光谱(IR)、核磁共振(NMR)、偏光显微镜(POM)、差示扫描量热法(DSC)对其结构与液晶性进行表征.结果表明,与对应的液晶基元相似PCSi-3G-C4显示向列相,但二者在熔点、清亮点和液晶态温区等方面存在一定差异. 相似文献
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Zhu Chen Ming Zhao Kang Liu Yuqing Wan Xudong Li Gang Feng 《Journal of materials science. Materials in medicine》2014,25(8):1903-1913
Traditional chitosan hydrogels were prepared by chemical or physical crosslinker, and both of the two kinds of hydrogels have their merits and demerits. In this study, researchers attempted to prepare one kind of chitosan hydrogel by slightly crosslinker, which could combine the advantages of the two kinds of hydrogels. In this experiment, the crosslinker was formed by a reaction between the isocyanate group of 1,6-diisocyanatohexan and the hydroxyl group of polyethylene glycol-400 (PEG-400), then the crosslinker reacted with the amidine and the hydroxyl group of ethylene glycol chitosan to form the network structure. Physical properties of the hydrogel were tested by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and biodegradation. Biocompatibility was assessed by cell implantation in vitro and the scaffold was used as a cartilage tissue engineering scaffold to repair a defect in rabbit knee joints in vivo. FTIR results show the formation of a covalent bond during thickening of the ethylene glycol chitosan. SEM and degradation experiments showed that the ethylene glycol chitosan hydrogel is a 3-D, porous, and degradable scaffold. The hydrogel contained 2 % ethylene glycol chitosan and 10 μl crosslinker was selected for the biocompatibility experiment in vitro and in vivo. After chondrocytes were cultured in the ethylene glycol chitosan hydrogel scaffold for 1 week cells exhibited clustered growth and had generated extracellular matrix on the scaffold in vitro. The results in vivo showed that hydrogel-chondrocytes promoted the repair of defect in rabbits. Based on these results, it could be concluded that ethylene glycol chitosan hydrogel is a scaffold with excellent physicochemical properties and it is a promising tissue engineering scaffold. 相似文献
13.
利用戊二醛(GLA)交联并负载La3+的壳聚糖吸附净化高氟地下水时,反应不完全的戊二醛可能会溶出而产生较大的生物毒性。选用低毒的乙二醇二缩水甘油醚(EGDE)替代GLA,对壳聚糖实施交联改性,生成交联壳聚糖微球(CEB),然后在CEB表面螯合La3+,制备新型除氟剂(CEB-La)。结果表明,交联温度是影响CEB-La吸附性能的最主要因素,交联的适宜条件为EGDE与CS的-NH2物质的量比为1∶2,20℃反应4h;螯合的适宜条件为将CEB按投加量2g/L加到0.020mol/L的La3+溶液中,40℃反应3h。所得到的吸附剂具有良好的稳定性,对质量浓度20mg/L含氟水的F-去除率达96%。红外光谱分析表明,EGDE与壳聚糖的-NH2、C6-OH发生交联反应,形成的交联产物CEB中,仲羟基与La3+配位。X射线衍射分析表明,壳聚糖微球在制备过程中结晶能力下降,有利于La3+的负载和F-的吸附,除氟剂中的镧主要以La-O化物的形式存在。 相似文献
14.
Almeida JF Fonseca A Baptista CM Leite E Gil MH 《Journal of materials science. Materials in medicine》2007,18(12):2309-2317
Recently there have been some developments in the preparation of controlled drug delivery systems for glaucoma. Many materials
are being used in this area, namely gelatine and chitosan. Both of them present high levels of biocompatibility and biodegradability.
In this paper, we wish to report the work we have been doing on the preparation and characterization of hydrogels based on
gelatine and chitosan. The crosslinking agents used were 1-(3-(Dimethylamino)propyl)-3-Ethylcarbodiimide hydrocholide (CDI),
1,4-Butanodiol diglycidyl ether (epoxyde 1), Ethylene glycol diglycidyl ether (epoxyde 2) and genipin. The results obtained
showed that all of the films were hydrogels. The surface and transversal cut showed a porous surface in all the films. The
thermal analysis proved the modifications in the polymeric chains, with the stabilization of all of them by the crosslinking
agents. The release pattern indicates that the gelatine films were the best since they release the adequate proportion of
drug. Finally, the cytotoxicity showed that the gelatine films were all biocompatible, specially the ones crosslinked with
one of the Epoxydes. 相似文献
15.
Van Viet Thai Byong-Taek Lee 《Journal of materials science. Materials in medicine》2010,21(6):1867-1874
In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4·2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid phase (20, 40 wt%). In each groups, the HPMC percentage was 0, 2, and 4 wt%. An increase in compressive strength due to changes in morphology was confirmed by scanning electron microscopy images. A good conversion rate of HAp at 20% citric acid was observed in the XRD profiles. In addition, HPMC was not obviously affected by apatite formation. However, both HPMC and citric acid increased the compressive strength of IBS. The maximum compressive strength for IBS was with 40% citric acid and 4% HPMC after 14 days of incubation in 100% humidity at 37°C. 相似文献
16.
采用H_3PO_4/HNO_3-NaNO_2氧化体系对竹浆纤维C6位进行选择性氧化,然后与壳聚糖溶液交联反应制备生态的抗菌壳聚糖改性竹浆纤维。固相CP/MAS 13 C核磁共振分析显示,H_3PO_4/HNO_3-NaNO_2已将竹浆纤维C6位上的伯羟基选择性氧化成羧基,且红外光谱和扫描电镜测试表明,壳聚糖的氨基与氧化竹浆纤维分子上的羧基发生酰胺化反应,壳聚糖分子通过C-N化学键共价交联在竹浆纤维上,并在竹浆纤维表面形成壳聚糖薄膜。通过分析H_3PO_4/HNO_3-NaNO_2氧化和壳聚糖处理过程中竹浆纤维羧基含量、机械强力、壳聚糖含量等指标,得出最佳工艺参数。Kjeldahl定氮分析得出壳聚糖在氧化竹浆纤维上的最大含量为3.92%。壳聚糖接枝竹浆纤维的断裂强度变化不明显,但其断裂伸长率降低。抗菌试验结果显示,与壳聚糖处理的原竹浆纤维抗菌性相比,壳聚糖改性竹浆纤维对大肠杆菌和金黄色葡萄球菌的抗菌效果明显提高,抑菌率均在96%以上,且壳聚糖改性竹浆纤维具有良好的抗菌耐洗涤性能。 相似文献
17.
Recent researches have largely been focused on chitosan, which is deacetylated chitin, the most abundant natural polysaccharide after cellulose. In this paper, we report the fabrication of gold nanoparticles (GNPs) by UV photoactivation in the presence of biopolymeric chitosan and the tracing of the gold salt solution aging. Detailed UV-visible spectroscopy study witnessed the evolution of the surface plasmon resonance (SPR) adsorption during the GNP growth. The effect of chitosan in aqueous solution for the GNP preparation was investigated in detail. The results indicated the size and distribution of GNPs could be controlled over by altering the concentration of chitosan, and the GNP growth during aging was a chitosan-mediated autocatalytic process. Fourier transform infrared spectroscopy (FTIR) showed the hydroxyl in molecular chitosan was oxidized to carbonyl groups in the fabrication of GNPs after aging and nitrogen atoms are the main sites for the complexation of chitosan with Au atoms. Our synthesis method in the present way can be used to form self-assemble monolayers of GNPs and fabricate biosensors based on surface plasmon resonance effect. 相似文献
18.
采用酰化反应将癸二酸胆甾醇单酯的羧基进一步与邻苯二甲酰化壳寡糖接枝聚己内酯(PHC-SO-g-PCL)的羟基反应制备了新型的胆甾醇支化的壳寡糖接枝聚己内酯热塑性生物材料(PHCS()-g-PCL-g-chol.).采用傅立叶红外光谱(FT-IR)对其化学结构进行了表征.通过偏光显微镜(POM)研究了癸二酸胆甾醇单酯(M)的液晶性能,表现为胆甾型液晶,同时可观察到该热塑性生物材料的熔融过程.采用示差扫描量热仪(DSC)对该生物材料的热性能进行表征,结果表明胆甾醇支化的壳寡糖接枝聚己内酯在89℃出现了熔融峰,因此具有热塑性,它克服了原壳寡糖分子间及分子内的强氢键作用,进而改善了壳寡糖的溶解性和功能性. 相似文献
19.
以壳聚糖(CS)和2,3-环氧丙基三甲基氯化铵(GTA)为原料,制备季铵化壳聚糖(QCS),将其与小分子游离胍(Guanidine)共混,借助戊二醛(GA)的化学交联作用,将季铵化壳聚糖中的氨基以及胍中的氨基交联,形成网状结构,由此制得含有不同含量Guanidine分子的交联QCS-G阴离子交换膜。实验过程中,对该膜的含水率、溶胀度、力学强度、电导率及耐碱稳定性等进行了详细的考察。结果表明,游离胍的引入可有效地提高膜的电导率和耐碱稳定性,同时降低了膜的溶胀度及含水率。其中小分子游离胍质量分数为2.5%的膜(QCS-G2.5%)在70℃时的电导率可达到6.58×10~(-2)S/cm;在10 mol/L NaOH溶液中浸渍72 h后该膜70℃测得的电导率损失仅为3.8%,离子交换量损失仅为3.82%,表明该膜的耐碱性能较好。 相似文献
20.
新型两亲性N-烷基-N-季铵化壳聚糖衍生物的制备与表征 总被引:2,自引:0,他引:2
以天然聚合物壳聚糖为原料,在其2-NH2上引入长链疏水基(n=8,10,12),制得N-烷基壳聚糖,然后在未取代的2-NH2进行季铵化得到两亲性的N-烷基-N-季铵化壳聚糖衍生物。通过FT-IR、13C-NM R、1H-NM R对其结构进行表征;用差示扫描量热法分析了物理性质。两亲性的N-烷基-N-季铵化壳聚糖衍生物可在水中自发形成21 nm~280 nm的胶束。 相似文献