明胶/海藻酸钠(京尼平交联)互穿网络膜的制备与性能

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。     

QCS/SiO_2有机/无机杂化膜的制备及其溶胀动力学研究

以季铵化壳聚糖(QCS)为主体膜材料,二氧化硅(SiO2)为无机前躯体通过溶胶-凝胶法制备QCS/SiO2有机/无机杂化膜,通过傅利叶变换红外光谱(FT-IR)、扫描电镜(SEM)和热失重分析(TGA)对制备得到的膜的结构、形貌以及热稳定性进行表征。同时,对QCS/SiO2杂化膜的溶胀机理、SiO2含量对该杂化膜溶胀度、溶胀速率和溶胀动力学的影响等因素进行了考察。结果表明:无机物质SiO2的含量对膜的溶胀过程有显著影响,随着SiO2含量的增加,溶胀速率常数呈现先增大而后减小的趋势。而且,该系列杂化膜在pH=7的水溶液中吸水溶胀时,溶胀过程遵循Schott’s二级溶胀动力学模型。另外,无机物质的引入优化了杂化膜的吸水溶胀过程,当杂化膜中无机物质SiO2含量为15%时(质量分数),初始溶胀速率(KsW2∞)为769.23,吸水速度较快。     

环氧树脂/二氧化硅杂化材料的制备与性能表征

溶胶-凝胶法制备环氧树脂/SiO2杂化材料,利用FTIR、SEM和综合热分析仪对杂化材料的结构、显微形态及热性能进行了表征.结果表明,杂化材料中SiO2与环氧树脂两相间存在氢键作用;SiO2质量分数＜7%时SiO2与环氧树脂之间无明显相界面,可获得有机聚合物链段与无机网络互穿的有机/无机杂化材料;SiO2质量分数为11%时材料具有最佳耐热性能.     

聚醋酸乙烯酯(PVAc)/聚离子液体(PILs)半互穿聚合物网络膜的制备及气体分离性能

利用紫外光固化法,制备了聚醋酸乙烯酯(PVAc)/聚离子液体(PILs)半互穿聚合物网络膜,用于CO2/N2的分离,并对其化学结构、形貌及热稳定性进行了表征.结果表明,加入PILs后,半互穿膜的热稳定性增加,并且PILs与PVAc的相容性较好,随着PILs含量的增加,PVAc/PILs半互穿膜的CO2和N2渗透系数和溶解度系数均提高,渗透选择性先增后减,当PILs含量为50%时达到最大值64.20.     

含偶联剂的聚酰亚胺/SiO2杂化膜的制备与性能

采用二酐(HQDPA)和二胺(ODA)合成了聚酰亚胺,以正硅酸乙酯(TEOS)为无机前驱体,通过溶胶-凝胶法在溶剂DMF中制备出SiO2不同含量的PI/SiO2杂化膜,偶联剂GOTMS用来加强聚酰亚胺与SiO2的相容性。采用SEM及万能拉力实验机对膜材料的微观结构和力学性能进行了表征。结果表明,质量分数为10%SiO2的杂化膜力学性能得到加强,20%,30%的膜力学性能下降;加入偶联剂有效地抑制了SiO2的团聚,20%,30%的杂化膜力学性能得到了改善。     

聚乙烯醇/海藻酸钙水凝胶的制备及其力学性能研究

采用冷冻-解冻交联聚乙烯醇(PVA),海藻酸钠(SA)交联Ca2+制备聚乙烯醇/海藻酸钙(PVA/Alg-Ca)互穿网络水凝胶。探究了影响混合水凝胶pH敏感性及平衡溶胀比的原因,考察了冷冻-解冻循环次数、Ca2+浓度、海藻酸钠含量对凝胶弹性模量(E)的影响。利用回归分析建立数学模型,实现对E定量控制,模拟细胞在体内生长的生物物理环境。数学模型模拟的相对误差不超过0.1,可实现对PVA/Alg-Ca互穿网格水凝胶力学性能的定量控制。     

聚氯乙烯/无机粒子复合膜的结构与性能

通过在聚氯乙烯(PVC)铸膜液中引入无机粒子二氧化硅,利用湿法相转化法成膜机理,制得一系列不同粒子含量的PVC/SiO2复合膜。对PVC/SiO2复合膜的形貌进行观察,分析和讨论了无机粒子SiO2含量对PVC/SiO2复合膜产生界面微孔的作用以及添加聚乙二醇(PEG)后PVC/SiO2复合膜性能的变化。结果表明,添加一定含量的二氧化硅可在PVC/SiO2复合膜中产生较明显的界面微孔结构,有效增强PVC/SiO2复合膜的通透性及力学性能,而PEG添加则有利于PVC/SiO2复合膜中界面微孔之间的贯通。     

二氧化硅填充聚氯乙烯杂化膜研究

在聚氯乙烯(PVC)纺丝液中适度加入二氧化硅(SiO2)无机粒子,以溶液相转化法制得PVG-SiO2杂化纤维膜.观察纤维膜的形貌,分析讨论SiO2含量和喷丝头拉伸比,对于产生界面微孔的作用及其与膜结构和性能的关系.结果表明,适量SiO2的加入,既可提高PVC纺丝液的稳定性,又使纤维膜产生界面微孔;在喷丝头拉伸比为2:1,SiO2含量为45%时,纤维膜中可产生较为明显的界面微孔结构,从而有效地提高其通透性.     

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。     

聚酰亚胺/SiO_2杂化膜的微观结构与力学性能

以聚酰亚胺(HQDDA-0DA)为基体,正硅酸乙酯(TEOS)为增强剂,在共溶DMF中,通过溶胶-凝胶法,制备出厚度约为20μm,不同含量SiO2的PI/SiO2杂化膜,用Fr-IR、SEM及万能拉力实验机对膜材料的微观结构和力学性能表征.结果表明,杂化膜中Si-OH和PI存在化学键;10%SiO2含量的杂化膜SiO2颗粒呈卵形镶嵌在PI基体中,取向与膜平行,随着SiO2含量的增加,颗粒尺寸增大,30%SiO2含量的杂化膜中,无机相形成部分的连续结构,并出现团聚;10%SiO2含量的杂化膜强度和模量均为最大,随着SiO2含量的进一步增加的膜的强度与模量均下降.     

海藻酸钙凝胶对牙本质小管封闭作用的实验研究

为治疗牙本质过敏症,研究了海藻酸钙对牙本质小管的封闭作用及矿化效果。以海藻酸钠(SA),碳酸钙,葡萄糖酸内酯(GDL)为原料,在牙本质上通过原位相转变制备海藻酸钙(CA)凝胶。测定了单一变量条件下不同海藻酸钠浓度、f值(钙离子与羧基的摩尔比)及n值(葡萄糖酸内酯与钙离子的摩尔比)对海藻酸钙凝胶的凝胶化时间和浸提液pH值的影响。扫描电镜观察海藻酸钠混合液处理前后牙本质微观形貌改变,并对封闭后牙本质小管进行了矿化研究。结果表明海藻酸钠浓度为2.5%、f=0.5及n=0.6为最佳配比。海藻酸钠处理后,开放的牙本质小管明显变小或封闭,显示海藻酸钠溶液可进入牙本质小管形成凝胶,并封闭牙本质小管。矿化后凝胶表面呈致密的矿化层,XRD分析为单一的高结晶羟基磷灰石,CA凝胶有利于诱导高结晶度HA的生成,为继续探索牙本质的仿生矿化提供新思路。     

Study on the combined dust suppression effect of sodium alginate and sodium fatty acid methyl ester sulfonate

To further improve the effect of dust control in coal mines and protect the health of workers, the effect of sodium alginate (SA) on the dust suppression ability of sodium methyl ester sulfonate (MES) was studied using molecular dynamics simulation. Scanning electron microscopy and X-ray photoelectron spectroscopy analyses were performed to compare the dust suppression effect of the SA/MES dust suppressant compound to MES by itself. The results show that when SA is present, the coal dust bonds together more, agglomerates into large particles, and settles. This finding is also consistent with the results of molecular dynamics simulations. In the analysis of relative concentrations and mean square displacement, the presence of SA can reduce the water diffusion on the coal surface, making it easier for coal dust to agglomerate. In addition, we analyzed the mode of action of SA through radial distribution and electrostatic potential, and determined that SA forms a unique networking chain structure to capture and retain water molecules. SA increases the probability of interaction between water and surfactant, thus increasing the amount of adsorption. This study provides a more in-depth understanding of the dust suppression mechanism of mixed dust suppressants.     

丝素/海藻酸钠膜韧性的优化及膜释药机理分析

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。     

海藻酸钠阳离子交换膜的改性及表征

以海藻酸钠(SA)为原料,以羧基化多壁碳纳米管(cMWCNTs)为改性剂,再通过涂敷浸渍的方法与热塑性聚氨酯(TPU)导电无纺布复合得到改性SA阳离子交换膜。利用热失重分析仪(TG)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)、绝缘电阻测试仪和万能材料试验机对SA阳离子膜的结构和性能进行表征。结果表明:与SA阳离子交换膜相比,经cMWCNTs和TPU导电无纺布改性后膜的电阻率显著降低,导电能力提高;改性SA阳离子膜的表面平整、光滑,未出现气泡等缺陷,TPU导电无纺布与SA膜间界面结合力较强;改性后,膜的热稳定性和力学性能得到显著提高。     

海藻酸钠/羽毛角蛋白复合纤维的制备与性能

采用酸碱法在鸭毛中提取羽毛角蛋白（FK）,通过正交实验研究了FK提取的最佳条件。将FK与海藻酸钠（SA）进行共混,制备SA/FK复合溶液,测试了复合溶液的流变性。通过湿法纺丝制备SA/FK复合纤维,研究了复合纤维的基本性能并表征了复合纤维分子间氢键作用。结果表明:在最佳提取条件下（提取温度为60.0℃,提取时间为120.00 min,碱浓度为2.00wt%）,FK产率最高为45.75%。SA/FK复合溶液的表观黏度随剪切速率的增加而减小,随FK含量的增加呈现先增后减的趋势。FK的加入使分子间氢键作用增强。SA/FK复合纤维的力学断裂强度能够达到1.96 cN/dtex。SA与FK的复合破坏了原有分子的晶体结构,SA/FK复合纤维分子结构是以非晶态存在。SA/FK复合纤维的表面具有均匀的沟槽结构。      

A novel wound dressing material — fibrin–chitosan–sodium alginate composite sheet

The present study describes preparation and characterization of fibrin–chitosan–sodium alginate composite (F–C–SA) in sheet form. F–C–SA composite was prepared and characterized for its physicochemical properties like water absorption capacity, surface morphology, FTIR spectra and mechanical properties. The optimum quantities of fibrin, chitosan and sodium alginate to get better mechanical properties to composite were determined. FTIR spectrum confirmed the interaction between amino groups of chitosan, fibrin and sodium alginate and SEM studies revealed composite nature of the material.     

Evaluation of alginate-chitosan semi IPNs as cartilage scaffolds

In this study, alginate and alginate:chitosan semi interpenetrating polymer network (IPN) scaffolds were prepared by freeze-drying process. Alginate scaffolds were crosslinked with different concentrations of CaCl₂, i.e. 0.5, 1 or 3% (w/v), in 96% (v/v) ethanol solutions for two different periods, i.e. 4 and 24 h, after freeze-drying. Scanning electron microscope (SEM)/ Energy Dispersive Analysis by X-ray (EDAX) analysis and swelling studies indicated that crosslinking of scaffolds with 3% (w/v) CaCl₂ for 24 h was effectively created suitable alginate scaffolds in terms of optimum porosity and mechanical stability. This is why, alginate:chitosan semi IPN scaffolds were prepared at the crosslinking condition mentioned above in 70:30, 60:40 and 50:50% (v/v) alginate:chitosan ratios. Besides the attachment and proliferation abilities of ATDC5 murine chondrogenic cells on alginate, 70:30% (v/v) alginate:chitosan and 50:50% (v/v) alginate:chitosan scaffolds, their cellular responses were assessed for chondrogenic potential. These structural and cellular outcomes demonstrate potential utility of chitosan semi IPNs in alginate scaffolds. Comparative results found in relation to alginate scaffolds, support the necessity for alginate:chitosan scaffolds for improved cartilage tissue engineering.     

油茶果壳氧化纳米纤维素-海藻酸钠复合薄膜的 制备及性能

以油茶果壳为研究对象,利用碱煮漂白法提取纤维素,并利用2, 2, 6, 6-四甲基哌啶-1-氧自由基（TEMPO）氧化法,制备TEMPO氧化纳米纤维素（TOCNs）,经离子交联法建立TEMPO氧化纳米纤维素与海藻酸钠（SA）的半互穿交联网络,制得综合性能优异的复合薄膜。对复合薄膜进行了结构表征,力学性能测试,热稳定性和阻氧性能测试。实验结果表明： TOCN/SA薄膜表面平整,有致密的内部层状结构,适量SA和TOCNs具有较好的相容性。当SA的掺杂质量分数达到42%时,TOCN/SA薄膜的断后伸长率较TOCN薄膜增长138.6%,氧气透过率降低15.55%,碳残余量较TOCN薄膜提高21.4%。因此,油茶果壳氧化纳米纤维素TOCN/SA复合薄膜,具有良好的力学性能和热稳定性,同时保持了较好的阻氧性能。     

Biodegradable IPN hydrogel beads of pectin and grafted alginate for controlled delivery of diclofenac sodium

A novel diclofenac sodium (DS) loaded interpenetrating polymer network (IPN) beads of pectin and hydrolyzed polyacrylamide-graft-sodium alginate (PAAm-g-SA) was developed through ionotropic gelation and covalent cross-linking. The graft copolymer was synthesized by free radical polymerization under the nitrogen atmosphere followed by alkaline hydrolysis. The grafting, alkaline hydrolysis, and characterization of beads were confirmed by Fourier transforms infrared spectroscopy. The crystalline structure of drug after encapsulation into IPN beads were evaluated by differential scanning colorimetry and X-ray diffraction analyses. DS encapsulation was up to 96.45 %. The effect of hydrolyzed graft copolymer/pectin ratios and glutaraldehyde concentration on drug release in acidic and phosphate buffer solutions were investigated. The release of drug was significantly increased with increase of pH. The release of drug depends on the extent of cross-linking. The results indicated that IPN beads of hydrolyzed PAAm-g-SA and pectin could be used for sustained release of DS.     

Preparation of Cross-Linked Sodium Alginate Microparticles Using Glutaraldehyde in Methanol

Polymeric sodium alginate microparticles were prepared by precipitating sodium alginate in methanol, followed by cross-linking with glutaraldehyde. The extent of cross-linking was controlled by the time of exposure to glutaraldehyde. The topology of microparticles was characterized by scanning electron microscopy (SEM), which indicated smooth surfaces. The equilibrium swelling experiments were carried out in water to observe the effect of cross-linking and drug loading for better utility of microparticles. It was found that swelling decreased, but drug loading increased, with an increase in cross-linking of the matrix.