Fe3O4/聚二甲基硅氧烷改性胶原海绵及其油水分离性能

为发展一种原料丰富、绿色环保、易于在复杂环境中操控使用、循环使用性好的多功能油水分离用海绵材料,采用浸渍法对胶原海绵进行聚二甲基硅氧烷(PDMS)/四氧化三铁(Fe₃O₄)纳米颗粒复合改性,制备了超疏水胶原基复合海绵(Fe₃O₄/PDMS-COL),表征了改性后化学结构与微观结构的变化,研究了油水分离性能。通过接触角测量可知：当胶原(COL)浓度为10 mg/mL、PDMS浓度为15vol%时,复合海绵的水接触角为150.3°。FTIR、XPS、XRD及TG测试结果表明Fe₃O₄/PDMS与胶原海绵成功发生复合,FE-SEM观察结果表明Fe₃O₄纳米粒子的加入可有效构造表面粗糙结构。海绵可吸附多种不同类型的油相如苯、正己烷、乙酸乙酯、真空泵油、花生油等,其中对乙酸乙酯的吸附量达47 g/g,且对不同油相的分离效率在99%以上。以苯为吸附物,连续循环使用20次后,海绵的接触角与磁性均未发生明显下降。海绵还可有效分离...     

羧甲基纤维素钠/甲壳素基复合调湿材料的制备与表征

采用甲壳素(CT)和羧甲基纤维素钠(CMC)为基质,与硅胶、无机盐氯化锂复合制备调湿材料,考察了基质配比、硅胶用量对调湿性能的影响,并利用红外光谱、扫描电镜对复合调湿材料的结构进行了表征。结果表明,在最佳配比m(CT)∶m(CMC)∶m(LiCl)∶m(硅胶)=2∶2∶2∶1所制得的调湿材料在25℃相对湿度分别为80%,60%和40%时,最大吸湿量可达到134%,70%和45%,添加硅胶的甲壳素和羧甲基纤维素钠基质复合调湿材料具有优异的吸放湿性能。     

金红石型纳米二氧化钛/聚二甲基硅氧烷复合改性制备多功能胶原海绵

胶原(COL)是一种来自于动物生物质的天然高分子材料，具有来源丰富、易加工、易修饰、可降解等优势。在胶原材料中，基于冻干处理而得的海绵具有天然多孔性，不仅为油相储存提供了充足的空间，还为功能微纳组分的固载提供了骨架网络。文中以胶原海绵为基底、聚二甲基硅氧烷(PDMS)为疏水改性剂、金红石型二氧化钛纳米颗粒(TiO₂)为光催化剂，制备出集疏水性、光催化效应及光响应抗菌性于一体的多功能复合胶原海绵TiO₂/PDMS-COL。使用场发射扫描电镜观察TiO₂/PDMS-COL的形貌，利用红外光谱、X射线光电子能谱、X射线衍射和热重分析对TiO₂/PDMS-COL的结构进行了表征。结果证实，TiO₂,PDMS与COL之间产生了复合作用。复合海绵对CHCl3的吸附容量可达134 g/g；循环使用20次后接触角下降较少。复合海绵对乳液也展现出良好的分离能力。模拟太阳光照射下，80min内复合海绵对罗丹明B的降解率达88%，且3次光照循环使用后其催化降解性能未发生明显下降。此外，光照下TiO<...     

新型仿生聚合物材料——胶原改性聚乳酸的合成与表征

乙二胺改性聚(DL-乳酸)(EMPLA)是实验室合成的一种含有丰富氨基和羧基、具良好亲水性且降解产物不呈酸性的生物材料.研究以二环己基碳二亚胺(DCC)为缩合剂,将Ⅰ型胶原共价引入到EMPLA中,制得了新型胶原改性聚乳酸(CPLA)仿生材料,探索并建立了一套向EMPLA基质中共价引入Ⅰ型胶原的液相合成技术.采用异硫氰酸荧光素(FITC)标记技术对CPLA的结构及胶原含量进行了定性表征.结果表明,采用本研究所建立的液相反应技术能将Ⅰ型胶原共价引入到EMPLA中,且CPLA中的胶原含量随EMPLA中乙二胺接枝率(EDA%)的增大而增大.     

介孔生物玻璃/丝素蛋白复合多孔海绵的结构及止血性能研究

采用冷冻干燥法制备了介孔生物玻璃(M58S)/丝素蛋白(SF)复合多孔海绵,采用透射电镜(TEM)和场发射扫描电镜(FESEM)等观察M58S和复合多孔海绵的形貌和结构特征,通过体外凝血实验、大鼠肝脏止血模型和体外细胞毒性实验评价复合多孔海绵的止血性能和细胞毒性。TEM显示M58S内部具有规则的纳米级介孔孔道,排列高度有序,比表面积达400m~2/g,平均孔径为7.3nm;FESEM显示复合海绵呈现多孔沟壑状结构,孔隙率80%;APTT和PT测试结果表明该复合多孔海绵主要通过作用于血液的内源性凝血系统途径促进凝血;小鼠肝脏止血模型显示当M58S含量15%时,复合多孔海绵的止血效果较好且优于明胶海绵,有望用作体外快速止血材料。     

RGDS和胶原改性聚(DL-乳酸) 的合成与表征

利用马来酸酐(MAH)、丁二胺(BDA)I、型胶原和RGDS粘附多肽依次对聚(DL-乳酸)进行了化学改性,制得了仿生细胞外基质材料——胶原改性聚乳酸(CPLA)和RGDS改性聚乳酸(RGDS-PLA)。采用FT-IR、GPC-MALLS、XPS、罗丹明比色法和茚三酮显色法对MAH改性聚乳酸(MPLA)和BDA改性聚乳酸(BDPLA)进行了定性定量表征,分别采用FITC荧光标记技术和氨基酸分析仪对CPLA和RGDS-PLA进行了定性定量测定。结果表明,按文中所述之制备技术,能将胞外基质组分如胶原和RGDS粘附多肽共价引入到PLA中,形成新型的仿生细胞外基质材料。     

聚乙烯/石墨/碳纤维增强复合材料的制备及其性能研究

将改性石墨和表面含有羟基的碳纤维与氯化镁复合,然后负载四氯化钛催化组分,制得复合载体型齐格勒-纳塔催化剂,最后经过乙烯原位聚合,制得含有多维碳材料的聚乙烯(PE)/石墨/碳纤维的新型复合材料。结果表明:改性石墨、碳纤维、氯化镁复合作为催化剂的载体,能够制得高活性的乙烯聚合催化剂。石墨、碳纤维和氯化镁的复合载体型催化剂制得的PE/石墨/碳纤维的新型复合材料力学性能较好,拉伸强度达到38.5MPa,断裂伸长率达到560%,冲击强度达到107kJ/m~2,分别比纯PE提高45.28%、28.74%和16.30%。     

胶原/TiO2纳米复合红外低发射率材料的制备与表征

用胶原与改性纳米TiO2复合得到新型有机-无机复合材料，研究复合物中胶原的含量随复合温度、pH的变化规律，并考察TiO2晶型、Al2O3包膜改性及戊二醛交联改性对复合材料红外发射率的影响．结果表明;胶原与改性纳米TiO2复合的最佳温度为50℃、pH为8．0，胶原含量最高可达9．45wt％，两者间较强的复合协同作用明显降低了材料的红外发射率，并提高了材料的热稳定性；复合材料经戊二醛交联改性后可形成紧密有序的网络层状结构，热稳定性进一步提高，红外发射率最低可降至0．502．     

一种用于高效油水分离的超亲水/水中超疏油改性聚氨酯海绵的制备

采用了一种简单、高效和环保的材料和方法用于油水分离,即使用戊二醛在聚氨酯海绵表面均匀覆盖一层聚乙烯醇/壳聚糖/SiO2(PVA/CS/SiO2)复合涂层,使其达到超亲水/水中超疏油的特点。这种新型的改性海绵可以用于持续的油水分离,不仅可以分离大豆油、泵油和硅油与水的混合物,而且具有超强的耐腐蚀性,可以分离酸性和碱性的含油废水。通过使用扫描电子显微镜来表征它表面粗糙结构和热重分析仪表征它良好的热稳定性。结果表明:当聚合物与SiO2质量比为1∶2时,改性海绵油水分离的效率最佳,可以达到98.4%左右。因此,本研究中的改性海绵是一种操作简单和绿色环保的材料。     

胶原基复合止血材料的研究进展及展望

胶原蛋白可用于多种止血场景，并凭借优越的性能和易于获取的特点逐渐取代传统止血材料。然而，不同剂型的胶原止血剂都存在各自的缺陷，如力学性能差、粘附性差等。虽然提纯或交联改性胶原能在一定程度上获得改善，但作用有限，临床应用仍深受限制。天然生物及其衍生物材料是来源丰富的止血剂，具有生物相容性和良好的吸收和降解性能。广泛使用的材料包括壳聚糖、纤维蛋白胶、藻酸盐和氧化纤维素，以及近年来逐渐受到重视的传统中药材。因此，胶原蛋白与天然生物及其衍生物材料交联而成的胶原蛋白基复合止血材料，有望成为极具前景的生物医用止血材料。本文综述了不同类型胶原基复合止血材料的研究进展，总结了各自的优缺点，最后对胶原基复合止血材料的未来发展方向进行了探讨。     

Antitumor activity and antioxidant role of a novel water-soluble carboxymethyl chitosan-based copolymer

In this study, a natural polymer, chitosan (CS) has been converted through modified procedures to produce a water-soluble nontoxic form that has been evaluated as a novel potential antitumor drug. CS was carboxymethylated and then further modified in mild aqueous medium via graft copolymerization using a new simple and reproducible method. The synthesized new derivative of carboxymethylated CS (DCMC) was fully characterized by numerous techniques including Fourier transform infrared spectroscopy (FT-IR), elemental analyzer (EA), scanning electron microscopy (SEM), two-dimensional wide-angle X-ray scattering (2D-WAXS), and differential scanning calorimetry (DSC). The anticancer activity of the DCMC was investigated using mice bearing Ehrlich ascites tumor cells (EAC) at different doses dissolved in isotonic saline. It has been found that treatment with DCMC significantly inhibited tumor growth in a dose-dependent manner. To better understand the molecular mechanism explaining the DCMC effect on cancer cells, we tested the response of EAC cells in vivo to DCMC using flow cytometry cell cycle analysis. The cell cycle analysis revealed a G₂/M phase accumulation as well as a significant increase in sub-G₁ phase cells after treatment with DCMC. This indicates an induction of apoptosis in EAC cells associated with a highly significant decrease in tumor volume. In general, our results indicated that the DCMC is a regulator of tumor cell growth and differentiation not only by causing G₂/M cell cycle arrest but also inducing their apoptotic death. Moreover, the estimated hematological profile such as hemoglobin, RBCs, as well as WBCs counts revealed normal levels in mice treated with DCMC, indicating the possibility of using the DCMC in cancer chemotherapy without causing anemia like other drugs. Biochemical assays also revealed that treatment with DCMC has led to an augmentation of the antioxidant defense system without affecting lipid peroxidation in EAC-bearing mice.     

Antitumor activity and antioxidant role of a novel water-soluble carboxymethyl chitosan-based copolymer

In this study, a natural polymer, chitosan (CS) has been converted through modified procedures to produce a water-soluble nontoxic form that has been evaluated as a novel potential antitumor drug. CS was carboxymethylated and then further modified in mild aqueous medium via graft copolymerization using a new simple and reproducible method. The synthesized new derivative of carboxymethylated CS (DCMC) was fully characterized by numerous techniques including Fourier transform infrared spectroscopy (FT-IR), elemental analyzer (EA), scanning electron microscopy (SEM), two-dimensional wide-angle X-ray scattering (2D-WAXS), and differential scanning calorimetry (DSC). The anticancer activity of the DCMC was investigated using mice bearing Ehrlich ascites tumor cells (EAC) at different doses dissolved in isotonic saline. It has been found that treatment with DCMC significantly inhibited tumor growth in a dose-dependent manner. To better understand the molecular mechanism explaining the DCMC effect on cancer cells, we tested the response of EAC cells in vivo to DCMC using flow cytometry cell cycle analysis. The cell cycle analysis revealed a G?/M phase accumulation as well as a significant increase in sub-G? phase cells after treatment with DCMC. This indicates an induction of apoptosis in EAC cells associated with a highly significant decrease in tumor volume. In general, our results indicated that the DCMC is a regulator of tumor cell growth and differentiation not only by causing G?/M cell cycle arrest but also inducing their apoptotic death. Moreover, the estimated hematological profile such as hemoglobin, RBCs, as well as WBCs counts revealed normal levels in mice treated with DCMC, indicating the possibility of using the DCMC in cancer chemotherapy without causing anemia like other drugs. Biochemical assays also revealed that treatment with DCMC has led to an augmentation of the antioxidant defense system without affecting lipid peroxidation in EAC-bearing mice.     

羧甲基纤维素复合膜的研究现状

目的介绍羧甲基纤维素与淀粉、海藻酸钠、明胶、纳米纤维素、壳聚糖和其他材料制备复合膜在国内外的研究进展,以及该类具有抑菌性能的食品包装复合膜的最新研究进展,为羧甲基纤维素复合膜的研究提供一定的思路和依据。方法总结该方向研究中不同材料的最佳添加量对羧甲基纤维素复合膜性能的提升情况,及一些复合膜添加不同的有机抑菌剂或无机抑菌剂后抑菌性能的提升情况和对一些食品的保鲜效果。结论羧甲基纤维素复合膜具有较大的应用潜力,添加一些材料后具有抑菌活性,该类复合膜在食品保鲜方面具有一定的应用价值。     

Influence of reduced graphene oxide on mechanical behaviors of sodium carboxymethyl cellulose

Sodium carboxymethyl cellulose/reduced graphene oxide (NaCMC/rGO) nanocomposite films were prepared by a simple solution mixing-evaporation method. The NaCMC/rGO nanocomposite films were characterized and compared with sodium carboxymethyl cellulose/graphene oxide (NaCMC/GO) nanocomposite films. The stability of the rGO dispersion, and the structural and mechanical properties of the composite films were investigated by UV–Vis spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and using a universal testing machine (UTM). The results revealed that CMC and rGO were able to form a homogenous mixture. Compared with pure CMC, the tensile strength and Young's modulus of the CMC/rGO nanocomposite films were considerably enhanced (by 72.52% and 131.79%, respectively) upon incorporation of 2 wt% rGO.     

Osseous regeneration in the presence of oxidized cellulose and collagen

Oxidized cellulose and collagen are two absorbable hemostatic scaffolding materials that are used widely in surgery. A histomorphological study was undertaken to determine the tissue response and extent of healing brought about by intraosseously implanting these two materials in the femur and tibia of sheep. There was no major difference in the rate of repair of the bone defects brought about by these two materials, with the bone defects being completely repaired by lamellar bone at 6-8 weeks. Therefore, our results suggest that, in most instances where collagen is presently used in surgical applications, it could be substituted by oxidized cellulose.     

豆渣可食性膜的制备及性能研究

以豆渣为基材,海藻酸钠和羧甲基纤维素为成膜剂,甘油为增塑剂,研究了成膜剂和增塑剂对膜性能的影响,并通过正交试验,优选了可食性膜的配方。结果表明,豆渣的添加量为2.0 g,羧甲基纤维素为1.4 g,海藻酸钠为1.0 g,甘油为1 mL时,可食性复合膜的综合性能良好。豆渣可食性膜的研究,既实现了废物利用,又保护了环境,具有广阔的发展前景。     

Hierarchical Assembly of Nanocellulose‐Based Filaments by Interfacial Complexation

In the present study, interfacial complexation spinning of oppositely charged cellulose‐materials is applied to fabricate hierarchical and continuous nanocellulose based filaments under aqueous conditions by using cationic cellulose nanocrystals with different anionic celluloses including soluble sodium carboxymethyl cellulose and insoluble 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy radical‐oxidized cellulose nanofibers and dicarboxylated cellulose nanocrystals (DC‐CNC). The morphologies of the wet and dry nanocellulose based filaments are further investigated by optical and electron microscopy. All fabricated continuous nanocellulose based filaments display a hierarchical structure similar to the natural cellulose fibers in plant cells. As far as it is known, this is not only the first report about the fabrication of nanocellulose based filaments by interfacial complexation of cationic CNCs with anionic celluloses but also the first demonstration of fabricating continuous fibers directly from oppositely charged nanoparticles by interfacial nanoparticle complexation (INC). This INC approach may provide a new route to design continuous filaments from many other oppositely charged nanoparticles with tailored characteristics.     

Novel preparation of expanded nano-graphene-based electrodes for EDLC and their improved electrochemical performance

The electrode raw materials in this work were composed of expanded nano-graphene (ENG)-based active carbon (YP50F) named YEG as an active material; Super-P carbon black (SPB) as an electric conductor; and styrene–butadiene rubber (SBR), sodium salt of carboxymethyl cellulose (CMC), and polytetrafluoroethylene ((C₂F₄)n, PTFE) as mixed binder materials. We characterized the prepared electrodes by X-ray diffraction, scanning electron microscopy, and Raman spectroscopic techniques. Finally, we examined the electrochemical performances of carbon materials in an electrolyte solution of tetraethylammonium tetrafluoroborate ((C₂H₅)₄NBF₄, TEABF4) in propylene carbonate (C₄H₆O₃, PC). The specific capacitance remains the same for smaller values of YEG in the composite electrodes. These results also provide evidence of the optimum loading of ENG in future graphene-based EDLCs.     

Characterization and temperature-dependent conductivity of polyaniline nanocomposites encapsulating gold nanoparticles on the surface of carboxymethyl cellulose

Polyaniline nanocomposites encapsulating gold nanoparticles on carboxymethyl cellulose surface were prepared via the polymerization of aniline hydrochloride with different carboxymethyl cellulose (CMC) concentrations (wt.%) using HAuCl₄ as oxidant. The synthesized composites were characterized by Fourier transform infrared (FTIR) spectroscopy. Surface morphology was studied by electron diffraction scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The embedded crystallinity of the composites was investigated by X-ray diffraction (XRD) analyses. The electrical property of the composites was examined by temperature-dependent DC conductivity in the range of 300–500 K. The composites exhibited higher electrical conductivities with increased CMC concentration under equivalent conditions. Activation energy for electron transport was also calculated based on the conductivity data.     

A biomimetic strategy to form calcium phosphate crystals on type I collagen substrate

ObjectiveThe aim of this study is to induce mineralization of collagen by introducing phosphate groups onto type I collagen from eggshell membrane (ESM) by treating with sodium trimetaphosphate (STMP). This strategy is based on the hypothesis that phosphate groups introduced on collagen can mimic the nucleating role of phosphorylated non-collagenous proteins bound to collagen for inducing mineralization in natural hard tissue.MethodThe collagen membrane was phosphorylated by treating it with a solution of STMP and saturated calcium hydroxide. The phosphorylated collagen was subsequently exposed to a mineralization solution and the pattern of mineralization on the surface of phosphorylated collagen substrate was analyzed. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), field emission electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and microhardness test were used to characterize the collagen substrate and the pattern of minerals formed on the collagen surface.ResultsThe FTIR and EDX results indicated that the phosphate groups were incorporated onto the collagen surface by treatment with STMP. During the mineralization process, the plate-like mineral, octacalcium phosphate (OCP), which was initially formed on the surface of ESM, was later transformed into needle-like hydroxyapatite (HAP) as indicated by the SEM, FESEM, EDX and XRD findings. The microhardness test displayed significant increase in the Knoop hardness number of the mineralized collagen.ConclusionsPhosphate groups can be introduced onto type I collagen surface by treating it with STMP and such phosphorylated collagen can induce the mineralization of type I collagen.