丝素纤维/硫酸钙抗感染骨材料的制备及性能

通过控制丝素蛋白自组装过程制备了溶液状态下的丝素纳米纤维(silk fibroin nanofibers,SFFs),与硫酸钙、万古霉素(vancomycin,VCM)复合,制备了VCM/CS/SFFs抗菌骨材料。通过SEM、XRD、紫外分光光度计、万能力学试验机、抑菌圈、MTT等手段分别研究了复合材料的微观形貌与结构、药物释放、力学、抑菌及细胞相容性等性能。结果显示,与水作为固化液相比,随着SFFs溶液(0.017 5~2.1 mg·m L~(-1))的加入,复合材料凝固时间可控,降解率逐渐降低,抗水性增强,韧性提高;同时随丝素纳米纤维含量的增加骨材料抗压强度表现为先增加后减小的趋势,一周内药物释放速率降低;材料同时具有抑菌作用;MTT实验结果显示,加入丝素纳米纤维后与纯的硫酸钙相比MC3T3细胞增殖明显。     

静电纺制备丝素蛋白纳米纤维及其复合纳米纤维的研究进展

将生物材料通过静电纺丝制备成的纳米纤维,具有比表面积大、空隙率高、生物相容性好等优点,因此得到广泛研究。本文主要综述了近年来国内外静电纺丝制备丝素蛋白纳米纤维的研究现状,重点介绍了采用不同溶剂制备的纯丝素蛋白纳米纤维和丝素蛋白与其它材料复合制备的丝素蛋白复合纳米纤维,并展望丝素蛋白纳米纤维潜在的应用前景。     

甲醇-水混合溶剂后处理制备丝素蛋白膜及其药物释放研究

采用溶液浇注法制备丝素蛋白薄膜, 应用傅里叶红外光谱(FTIR)和X 射线衍射(XRD)研究了浓度不同的甲醇-水混合溶剂处理后丝素蛋白薄膜的结构变化, 并以罗丹明B 为模型药物与丝素蛋白构建药物缓释体系, 考察了丝素蛋白膜的结晶结构对药物释放动力学的影响. 结果显示, 在甲醇体积比浓度Φ_MeOH＝50%～90%的范围内, 丝素蛋白材料中以β-折叠为主的silk Ⅱ 结晶含量随着混合溶剂中甲醇浓度的增加而先增加后下降, 在Φ_MeOH＝80%附近出现最大值. 罗丹明B 从丝素蛋白膜的释放属于Fickian 扩散机理, 其扩散指数n 随着丝素蛋白膜中β-折叠含量的增加而增加, silk Ⅱ结晶是丝素蛋白材料药物释放的天然调节器.     

PU/MOMMT纳米复合材料的制备与研究

纳米复合材料由于其纳米尺寸效应，表面效应以及纳米粒子与基体界面间强的相互作用，具有优于相同组分常规复合材料的力学、热学等性能，引起了人们的广泛关注。用纳米材料改性聚合物，制备纳米复合材料是获得高性能高分子复合材料的重要方法。1998年以来，Pinnavaia等首先制备了聚氨酯，蒙脱土（PU／MMT）纳米复合材料，研究了有机蒙脱土在聚醚中的分散性。其后Chen等将聚羟基己内酯/蒙脱土（PCL／MMT）纳米复合材料加入到PCL和二苯基甲烷-4，4＇-二异氰酸酯（MDI）合成的预聚体与1，4-丁二醇扩链反应后的溶液中，制备了PU／MMT纳米复合材料。少量PCL／MMT的引入可使复合材料的综合性能大幅提高。     

静电纺丝法制备三维聚二甲基硅氧烷纳米通道

利用静电纺丝技术构建了新型三维纳米通道系统。 在不同质量分数的聚苯乙烯（PS：Mw=1.3×105）溶液中加入一定量十二烷基磺酸钠（SDS）,于不同电压下进行静电纺丝。 所得纤维在90 ℃加热粘连后,形成三维聚苯乙烯纳米网络模板,然后于聚二甲基硅氧烷(PDMS)预聚体（含10%交联剂）灌注进入上述模板并交联形成网络复合材料,再用二硫化碳超声除去聚苯乙烯纤维。 采用扫描电子显微镜、透射电子显微镜对纤维模板形貌和纳米通道进行了表征。 结果表明,质量分数为10%的PS溶液加入0.5%SDS,在20 kV电压下进行静电纺丝,得到直径为150 nm的纤维。 SDS的加入对纺丝纤维具有平滑作用,使得粘连的纤维模板更易去除,形成的三维纳米通道直径约160 nm,与纤维模板直径一致。 该类型纳米通道可以应用于医学药物载体、纳流控芯片等众多领域。     

β-羟基丁酸与β-羟基戊酸共聚物 (PHBV)/蒙脱土纳米复合材料的结构与性能

用溶液复合法成功地制备了插层型PHBV／蒙脱土纳米复合材料。采用X射线衍射（XRD）和透射电子显微镜（TEM）研究了复合材料的结构，硅酸盐片层间距从1.8nm升至2.4nm左右。同时研究了复合材料的结晶，熔融，动态力学行为和力学性能，发现有机蒙脱土的加入，可以加快PHBV的结晶,降低熔融温度，使基体的玻璃化转变温度升高，提高了材料的力学性能，有机蒙脱土含量在3％时，其综合性能最佳。     

功能化石墨烯/聚苯胺复合电极材料的制备和电化学性能

利用水合肼还原十八胺（ODA）接枝的氧化石墨烯（GO）,得到了十八胺功能化石墨烯（ODA-G）,将ODAG与聚苯胺（PANI）通过溶液共混法,制备了功能化石墨烯和聚苯胺纳米复合材料（ODA-G/PANI）. 采用傅里叶变换红外（FTIR）光谱、X射线衍射（XRD）、热重分析（TGA）、拉曼（Raman）光谱及透射电镜（TEM）,对复合材料的结构和形貌进行了表征;利用循环伏安、恒流充放电及交流阻抗谱等,对复合材料的电化学性能进行了测试. 结果显示,少量ODA-G的引入为PANI 的电化学氧化还原反应提供了更多的电子通道和活性位置,有利于提高PANI 的赝电容. 在电流密度1.0 A·g^-1下,2%（w）ODA-G/PANI 的比电容达到787 F·g^-1,而相应的PANI 仅有426 F·g^-1. 此外,ODA-G/PANI的循环稳定性也远高于纯PANI.     

多孔碳纳米纤维负载Pd纳米颗粒用于增强电催化氧还原性能

采用溶剂热法合成了以锆为金属核心、2-氨基为配体的锆基金属有机骨架（UiO-66）纳米材料,通过静电纺丝技术制备出UiO-66自由分散的聚丙烯腈（PAN/UiO-66）纤维,可控热解得到多孔碳纳米纤维（porous carbon nanofibers,PCNFs）,结合湿化学还原法在PCNFs表面沉积Pd纳米颗粒,得到PCNFs@Pd复合材料。通过扫描电子显微镜、透射电子显微镜、X射线衍射技术对其形貌、组成、结构进行表征;采用电化学工作站分别测试了PCNFs@Pd在0.1 mol·L^-1 KOH和0.1 mol·L^-1 HClO₄电解质中氧还原性能（oxygen reduction reaction,ORR）。结果表明,在PAN纤维中添加UiO-66显著提高了PCNFs@Pd（Pd负载量为0.34%）复合材料的ORR性能。相比40% Pt/C,在碱性电解质中,PCNFs@Pd复合材料展示出更低的Tafel斜率、更优异的循环稳定性和耐甲醇中毒性。在酸性电解质中也表现出类似20% Pt/C的催化活性和循环稳定性。     

纳米羟基磷灰石/丝素蛋白复合支架材料的降解特性及生物相容性研究

应用共混法制备了纳米羟基磷灰石/丝素蛋白复合支架材料, 通过体外降解和细胞培养实验研究了复合支架材料的降解特性和生物相容性. 体外降解实验结果显示, 复合支架材料具有稳定的降解能力; 在降解过程中, 羟基磷灰石由于与降解液发生钙、磷等离子的交换, 使其结晶得到了进一步生长和完善. 利用细胞计数法、四甲基偶氮唑盐(MTT)比色法和碱性磷酸酶(ALP)活性测定等分析了复合支架材料的生物相容性, 结果表明, MG63细胞在复合支架材料上具有良好的粘附、增殖能力, 并可引起早期的骨分化. 因此, 纳米羟基磷灰石/丝素蛋白复合支架作为骨组织工程的支架材料具有良好的应用前景.     

核-隔层-壳结构Fe3O4@MoO3@mSiO2纳米载体的合成及其药物可控释放

利用加热均匀、迅速、热平稳性好和安全性高的微波热响应来实现药物的微波可控释放。引入具有微波热响应性质、热稳定性和化学稳定性好的MoO₃作为微波吸收物质,制备了核-隔层-壳结构Fe₃O₄@MoO₃@mSiO₂纳米药物载体。研究该纳米载体对药物布洛芬（IBU）的负载和微波响应可控释放过程。该纳米载体具有高的比表面积（222 cm²·g^-1）和较大的孔隙体积（0.14 cm³· g^-1）可用来负载药物。同时还具有较好的磁响应性,可实现药物的靶向给药,具有相对好的微波热响应性,可通过MoO₃中间层吸收微波辐射实现药物的可控释放。结果表明,在持续微波辐射360 min时IBU的释放率达到86%,远远高于仅搅拌时的释放率。     

Preparation and thermal analysis kinetics of the core–nanoshell composite materials doped with Sm

The core–nanoshell composite materials with magnetic fly-ash hollow cenosphere as core and nano SmFeO₃ as shell were synthesized by high-energy ball milling method. The magnetic fly-ash hollow cenosphere, samarium nitrate, and iron nitrate were used as raw materials. The synthesis and growth kinetics of the composite materials were investigated using the thermogravimetry and differential thermal analysis (TG–DTA) at different heating rates. The results show that the precursor of the composite materials decomposes in three steps. The apparent activation energy of each stage was calculated using the Doyle–Ozawa and Kissinger methods. The reaction order, frequency factor, and rate equations were also determined. The activation energy of the nano crystallite growth is calculated to be 16.12 kJ mol^?1 according to kinetics theory of nano crystallite growth. It can be inferred that the crystallite grows primarily by means of an interfacial reaction during the thermal treatment. The magnetic properties and microwave absorbing properties of samples were analyzed by the vibrating sample magnetometer analysis and vector network analyzer. The results indicated that the exchange coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which cause outstanding magnetic properties. In the frequency between 1 MHz and 1 GHz, the absorbing effectiveness of the composite absorbers can achieve ?32 dB. The magnetic properties of the composite material are better than those of single phase. So it is consistent with requirements of the microwave absorbing material at the low-frequency absorption.     

二维六方p6mm有序介孔WO_3-TiO_2复合材料的制备及其可见光光催化性能

以非离子型表面活性剂为模板剂,采用蒸发诱导自组装法制备了一系列不同WO3含量的有序介孔WO3-TiO2复合材料,并表征了其孔结构、形貌、孔隙率、光谱性质及组成.结果表明,该材料呈二维六方p6mm对称和锐钛矿晶相结构;与无序WO3-TiO2复合材料相比,其比表面积(152～154m2/g)更大,孔径更均一(5.3nm),且比纯TiO2的帯隙宽度(3.0eV)更窄.将该WO3-TiO2样品用于可见光光催化降解水相中罗丹明B和2,4-二氯苯氧乙酸的反应中,发现WO3含量适当的有序介孔WO3-TiO2样品的光催化活性比无序的样品和纯TiO2的更高.     

锂离子电池复合正极材料xLiFePO4·yLi3V2(PO4)3的复合机制

以FePO4·xH2O、V2O5、NH4H2PO4和Li2CO3为原料, 以乙二酸为还原剂, 通过湿化学还原-低温热处理方法制备出锂离子复合正极材料xLiFePO4·yLi3V2(PO4)3. X射线衍射(XRD)结果表明, 合成的材料中橄榄石结构的LiFePO4和单斜晶系的Li3V2(PO4)3两相共存; 从复合材料中LiFePO4、Li3V2(PO4)3相对于相同条件下制备的纯相LiFePO4和Li3V2(PO4)3的晶格常数变化以及结合高分辨透射电子显微镜(HRTEM)、能量散射X射线(EDAX)的结果可以看出, 在复合材料xLiFePO4·yLi3V2(PO4)3中存在部分V和Fe, 分别掺杂在LiFePO4和Li3V2(PO4)3中, 并形成固溶体; X射线光电子能谱(XPS)结果表明, Fe/V在复合材料中的价态与各自在LiFePO4和Li3V2(PO4)3中的价态保持一致, 分别为+2 和+3价. 充放电测试表明, 制备出的复合正极材料电化学性能明显优于单一的LiFePO4和Li3V2(PO4)3; 循环伏安测试表明, 复合正极材料具有优良的脱/嵌锂性能.     

Calcification mechanism and bony bonding studies of calcium carbonate and composite aluminosilicate/calcium phosphate applied as biomaterials by using radioactivation methods

Bony grafts are used as a filling biomaterial for defective bone. The introduction of new range of synthetic materials offers to surgeons additional possibilities to avoid virus transmission risks by using natural grafts in bony surgery. In this work, two materials, synthetic calcium carbonate and composite aluminosilicate/calcium phosphate were synthesized by an original method and experimented “in vivo” as biomaterials for bony filling. Extracted biopsies were studied by several physico chemical and biological methods. The aim was to evaluate the kinetic resorption and bioconsolidation of these materials. We focused on the bioconsolidation between implant and bone by realising cartographies from the implant to the bone and on the calcification mechanism by determination of the origin of Ca and Sr responsible of the neo-formed bone. Neutron activation analysis (NAA), radiotracers ⁴⁵Ca* and ⁸⁵Sr* and proton-induced X-ray emission (PIXE) were used. Concerning the synthetic calcium carbonate, results show that twelve months after implantation, the mineral composition of implant becomes similar to that of the mature bone. The neoformed bone is composed with Ca and Sr coming from the organism when the Ca and Sr of the implant were progressively eliminated. Concerning the composite geopolymer/calcium phosphate, PIXE and histological studies reveal the intimate links between the bone and the implant starting with the first month after implantation.     

High rate capability of Fe/FeO/Fe3O4 composite as anode material for lithium-ion batteries

Fe/FeO/Fe₃O₄ composite was synthesized by a simple solid method using ferric citrate and phenolic resin as raw materials. The reaction processes of raw materials mixture were characterized by thermogravimetric analysis (TGA) under nitrogen. X-Ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the structure and morphology of the products. The results showed that the obtained material was octahedral Fe/FeO/Fe₃O₄ composite with a size of 2-4 μm. The electrochemical performances of Fe/FeO/Fe₃O₄ composite as anode material were also evaluated, which exhibited a stable specific capacity of 260.3 mAh g^-1 and an ideal initial coulombic efficiency of 90.8% in the range of 0.05~3 V at the 5C rate. A good rate capacity of Fe/FeO/Fe₃O₄ composite electrode was also shown by the charge-discharge testing even at the rate of 60C. The better rate capability of Fe/FeO/Fe₃O₄ electrode could be measured in higher temperature.     

Bioactive Properties of Chitin/Chitosan—Calcium Phosphate Composite Materials

Calcium phosphate coating over phosphorylated derivatives of chitin/chitosan material was produced by a process based on phosphorylation, Ca(OH)₂ treatment and SBF (simulated body fluid solution) immersion. Chitin/chitosan phosphorylated using urea and H₃PO₄ and then soaked in saturated Ca(OH)₂ solution at ambient temperature, which lead to the formation of thin coatings formed by partial hydrolysis of the PO₄ functionalities, were found to stimulate the growth of a calcium phosphate coating on their surfaces after soaking in 1.5 × SBF solution for as little as one day. The Ca(OH)₂ treatment facilitates the formation of a calcium phosphate precursor over the phosphorylated chitin/chitosan, which in turn encourages the growth of a calcium deficient apatite coating over the surface upon immersion in SBF solution. The bio-compatibility of calcium phosphate compound—chitin/chitosan composite materials was evaluated by cell culture test using L-929 cells. The initial anchoring ratio and the adhesive strength of L-929 cells for composites was higher than that for the polystyrene disk (LUX, control). The results of in-vitro evaluation suggested that the calcium phosphate—chitin/chitosan composite materials were suitable for cell carrier materials.     

新型超分子复合发光材料四足配体铕配合物-蒙脱土的插层组装及发光性质

通过离子交换反应将四足配体铕配合物[EuL(NO3)]2+[L=1,1,1’,1’-四(吡啶-2-羧酸酯基)联三甲基丙烷]插层组装到蒙脱土(MT)层板间, 制备出一种新型的超分子复合发光材料[EuL(NO3)]2+-MT. 用元素分析、XRD、FTIR、UV-Vis和热分析对材料进行了表征, 并对其荧光性质进行了研究. 结果表明, 复合材料保持了蒙脱土良好的层柱结构特征, 其层间距d(001)值与插层配离子的直径吻合得较好, 配离子以单层形式分布于蒙脱土层板间. 在紫外光激发下, 复合材料发出较强的Eu3+特征荧光, 其相对荧光强度、荧光单色性和荧光寿命大大优于相应配合物的乙醇溶液. 复合材料中配合物的发光性能、光稳定性和热稳定性较纯配合物有明显提高.     

Preparation of Chitinous Compound/Gelatin Composite and Their Biological Application

Chitin, a natural abundant polysaccharide, have been investigated as prospected biochemical material due to its several biological advantages. It is insoluble in the most of the organic solvents due to its rigid crystalline structure. However, chitin regenerated hydrogel (RG) has been prepared by using the saturated calcium solvent system under mild conditions. And also, swelling hydrogel (SG) was prepared by using water. In this study, we prepared the suspension of chitinous hydrogel, and applied to fabricated the chitinous compound/gelatin composite sheets. Additionally, N-acetyl D-(+)-glucosamine was added into some composite sheets. We investigated the mechanical properties and growth of NIH/3T3 fibroblast cell for the prepared composite sheet.     

B-Co3O4/C复合纳米材料的制备及其电催化析氧性能

本文以雪莲果为碳源,采用热解法制备碳材料(C),以硝酸钴、四硼酸钠和碳材料为原料,通过热解法合成硼掺杂四氧化三钴/碳(B-Co₃O₄/C)复合纳米材料。运用XRD、FTIR、SEM、XPS等手段对其结构、形貌和组成进行表征。利用线性扫描(LSV)和Tafel曲线等电化学测试方法研究了B-Co₃O₄/C复合纳米材料的电催化析氧反应(OER)性能。结果表明,该材料具有较好的电催化OER活性。在1.0mol/L的KOH电解液和10mA·cm^-2的电流密度下,B-Co₃O₄/C复合纳米材料的过电位为293mV,Tafel斜率为45.0mV·dec^-1。在10mA·cm^-2电流密度下连续测试10h, B-Co₃O₄/C的电位变化不大,通过法拉第效率测试该催化剂的产氧效率为94%,说明硼原子的掺入改变了B-Co₃O₄...