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Elvio A. Campos Yoshitaka Gushikem Maria do Carmo Gonçalves Sandra C. de Castro 《Journal of colloid and interface science》1996,180(2):453
The Nb2O5/cellulose composite was prepared by reacting α-cellulose with NbCl5-n(OC2H5)n, in nonaqueous solvent, under nitrogen atmosphere and submitting the obtained material to hydrolysis. An increase in the crystallinity degree is observed in the composite material because the precursor reagent reacts with the amorphous phase of the cellulose fibers. Loadings between 4.5 and 16.0% of the oxide were achieved and in every case the oxide particles uniformly cover the fiber surface. Lewis and Brønsted acid sites were determined by using pyridine as the basic molecular probe. 相似文献
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V. V. Spiridonov I. G. Panova M. I. Afanasov S. B. Zezin A. V. Sybachin A. A. Yaroslavov 《Polymer Science Series B》2018,60(1):116-121
The one-step synthesis of water-soluble composites from maghemite (γ-Fe2O3) nanoparticles with a diameter of 12 ± 4 nm and a biocompatible polysaccharide, namely, sodium salt of carboxymethyl cellulose, is described. The role of the polymer matrix consists in stabilization of the resulting nanoparticles by the electrostatic interaction of polymer carboxyl groups with the surface atoms of iron in the (3+) oxidation state. The dissolution of the composites in water affords aggregatively stable dispersions responding to the external magnetic field. The content of the magnetic phase (iron oxide) in the formulation of the maghemite–carboxymethyl cellulose composite is defined by the ratio of components during the synthesis. 相似文献
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以异佛尔酮二异氰酸酯(IPDI)、聚醚二醇(N-210)、二羟甲基丙酸(DMPA)、一缩二乙二醇(DEG)、三羟甲基丙烷(TMP)及纳米氧化锡锑(ATO)浆料为主要原料,制备了稳定的纳米ATO改性水性聚氨酯(APU)乳液。 粒径测试及透射电子显微镜(TEM)观察显示,纳米ATO在水性聚氨酯中分散较好,乳液粒径均小于100 nm; FTIR分析表明,纳米ATO粒子与水性聚氨酯(WPU)间可能存在化学键; 热重分析(TGA)测试显示,随纳米ATO添加量的增加,胶膜最大热分解温度逐渐提高,最大提高了约20 ℃;紫外-可见-近红外吸收及保温性能测试表明,随着纳米ATO添加量的提高,胶膜在800~2500 nm的透过率逐渐降低,但涂层在可见光区透过率均超过70%,热阻率由1.34×10-2 m2·℃/W提高至3.17×10-2 m2·℃/W。 相似文献
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聚乙烯醇/半纤维素/纤维素纳米晶复合膜的制备和性能 总被引:1,自引:0,他引:1
通过碱解醇沉法从玉米芯中提取半纤维素,进而采用溶液共混流延法制备出不同比例的聚乙烯醇(PVA)/半纤维素共混膜,在此基础上加入通过硫酸水解脱脂棉制备的纤维素纳米晶(NCC),制备了NCC增强的复合膜.DSC、TGA、FTIR、SEM和薄膜拉伸等研究表明,复合膜的各组分间形成了氢键作用,相容性良好.在PVA/半纤维素共混膜中,半纤维素的加入大幅度提高了复合膜的断裂伸长率:当PVA与半纤维素质量比为3∶1时,复合膜的断裂伸长率高达380%,比纯PVA的140%增加了1.7倍,而拉伸强度仍能保持在较高的水平;纤维素纳米晶的加入,还可改善复合膜的韧性;半纤维素对PVA组分的结晶性能产生了影响,而刚性结构的NCC则对PVA的结晶起抑制作用.此外半纤维素和NCC的引入也提高了复合膜的热性能,使第二阶段分解速率峰的温度提高了约50℃. 相似文献
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首先,以磺化聚醚醚酮(SPEEK)为光敏自由基载体,以聚乙烯醇(PVA)为分散稳定剂,制备了具有光生自由基功能的SPEEK/PVA高分子膜;然后,通过在SPEEK/PVA膜上紫外光诱导Ag+还原生成纳米银颗粒(AgNPs),从而得到SPEEK/PVA-AgNPs复合膜。采用紫外可见分光光度计(UV-Vis)、扫描电镜(SEM)、能谱仪(EDS)、X射线光电子能谱分析(XPS)及傅里叶变换红外光谱(FT-IR)等手段对SPEEK/PVA-AgNPs材料进行了表征。结果显示:生成的银颗粒为纳米级,较均匀地分布在SPEEK/PVA高分子膜表面,SPEEK/PVA-AgNPs复合膜整体呈现棕色;形成的银纳米颗粒具有较完整的晶型,且价态分析显示其为单质。 相似文献
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PET表面锐钛矿-板钛矿相TiO2薄膜的制备及表征 总被引:1,自引:0,他引:1
利用改进的溶胶-凝胶法在经表面改性的PET(聚对苯二甲酸乙二醇酯)表面制备得到TiO2薄膜. 利用X射线衍射(XRD)、原子力显微镜(AFM)、UV-Vis 透光率曲线、接触角测试仪等测试手段对TiO2样品的性能进行表征.结果表明, PET表面过渡层的引入有效地改善了有机基底与无机薄膜之间的界面相容性, 在其表面形成透明、均一、附着力良好且具有光催化活性的TiO2薄膜.通过控制实验过程, 在低温下成功制备了不同锐钛矿/板钛矿比的TiO2薄膜,同时发现适量板钛矿相的存在能有效提高薄膜的光致亲水性. 相似文献
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Zilong Deng Zixuan Wu Xiao Tan Fangkun Deng Yaobang Chen Yanping Chen Hongcai Zhang 《Molecules (Basel, Switzerland)》2022,27(23)
To improve the mechanical and antibacterial properties of traditional starch-based film, herein, cellulose nanocrystals (CNCs) and chitosan nanoparticles (CS NPs) were introduced to potato starch (PS, film-forming matrix) for the preparation of nanocomposite film without incorporation of additional antibacterial agents. CNCs with varied concentrations were added to PS and CS NPs composite system to evaluate the optimal film performance. The results showed that tensile strength (TS) of nanocomposite film with 0, 0.01, 0.05, and 0.1% (w/w) CNCs incorporation were 41, 46, 47 and 41 MPa, respectively. The elongation at break (EAB) reached 12.5, 10.2, 7.1 and 13.3%, respectively. Due to the reinforcing effect of CNCs, surface morphology and structural properties of nanocomposite film were altered. TGA analysis confirmed the existence of hydrogen bondings and electrostatic attractions between components in the film-forming matrix. The prepared nanocomposite films showed good antibacterial properties against both E. coli and S. aureus. The nanocomposite film, consist of three most abundant biodegradable polymers, could potentially serve as antibacterial packaging films with strong mechanical properties for food and allied industries. 相似文献
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将再生丝素蛋白(SF)与纳米生物活性玻璃(NBG)粉体复合成膜,制备出一种新型生物材料。采用场发射扫描电镜(FESEM)、红外光谱(FT-IR)、热重分析(TGA)等方法对复合膜结构进行表征。结果表明:NBG均匀分散在丝素膜中,随着NBG含量的增加,复合膜中丝素的构象部分由无规线团或SilkⅠ向SilkⅡ转变,同时力学性能变差。体外生物活性研究表明:复合膜表面沉积出较多的类骨羟基磷灰石(HA),说明其具有较高的生物活性及优良的诱导类骨HA沉积的能力。 相似文献
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具有低表面自由能有机介电薄膜的制备及表征 总被引:1,自引:0,他引:1
通过自主开发的有机镀膜技术在Mg-Mn-Ce镁合金表面制备了具有低表面自由能和较高介电常数的有机纳米薄膜. 利用X射线光电子能谱(XPS)分析了表面有机镀膜过程的反应机理, 借助傅里叶变换红外(FT-IR)光谱进一步确认表面有机膜层的存在, 采用接触角测量仪测定了有机薄膜的蒸馏水接触角和表面自由能变化, 使用椭圆偏振光谱仪研究了薄膜的厚度, 并借助精密阻抗分析仪评价了薄膜的介电性能. 有机镀膜后镁合金表面形成了一层纳米级厚度的有机薄膜, 接触角从基体的70.8°上升至150.5°, 表面自由能从基体的37.96 mJ·m-2降低到1.57 mJ·m-2, 镁合金表面从亲水性转变为疏水性; 薄膜的厚度和质量随有机镀膜时间延长先增加后有所减小, 在镀膜20 min时薄膜性能最佳, 此时膜重达到23.5 μg·cm-2, 膜厚最大为147.48 nm, 其相对介电常数也达到最大, 在1 kHz下可达24.922. 相似文献
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《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1981,37(12):1067-1069
In the antimony(III) and bismuth(III) complexes of 2-methyl-benzoxazole: SbX3·L (X = Cl, Br), SbI3·2.5L, MX3·L·H2O (M = Sb, X = I; M = Bi, X = Cl, Br), SbCl4·HL, SbBr5·2HL, BiCl5·2HL. Bi2X9·3HL (X = Br, I) the ligand is O-bonded to the metal. 相似文献
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锑(III)在铂电极上的欠电位沉积行为 总被引:3,自引:0,他引:3
由于经欠电位沉积(UPD)形成的吸附金属原子居可以改变电极表面的结构和组成,从而达到增强电祝活性的目的,因此欠电位沉积在电化学领域中颇受重视.对于梯(Ⅲ)的欠电位沉积行为,自1953年Mills和Wills发现锑(Ⅲ)可在AS电极上形成单电子层[1]以后,Schimide等人和Motoo等人分别研究证实梯(Ⅲ)可在Au电极上[2]和Pt电极上[3]发生火电位沉积,并且Motoo等人使用梯(V)化合物测定了每个吸附梯原子占据的铂原子数[4].本文试图用电位扫描法、微分电容法、电位阶跃法等实验方法对锑(Ⅲ)在柏电极上的大电位沉积并为进行系统的研究… 相似文献
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Shilin Liu Jinping Zhou Lina Zhang Jianguo Guan Jianbo Wang 《Macromolecular rapid communications》2006,27(24):2084-2089
Summary: A polymer‐iron oxide nanocomposite film has been successfully synthesized by using a microporous regenerated cellulose film as template and aqueous ferrous chloride as precursor. The nanocomposite film was investigated with XRD, XPS, SEM, TEM, and VSM. The nanoparticles synthesized in situ were disk‐shaped with a mean diameter of ≈24 and thicknesses of 2.5–3.5 nm. For the first time, the nanodisks were well aligned in the cellulose matrix to form an ordered multibilayer structure by the shrinkage of the hybrid film while drying. The nanocomposite film displayed anisotropic magnetic properties as a result of the alignment of magnetic nanodisks. This work provides a novel and facile method for template synthesis of nanoparticles and aligned nanocomposites.
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纤维素超细纤维增强大豆分离蛋白透光复合膜性能研究 总被引:5,自引:1,他引:5
以醋酸纤维素为原料, 由静电纺丝方法得到平均直径为430 nm的纤维素超细纤维, 将该纤维与大豆分离蛋白复合制备了一种新型的超细纤维增强透光复合膜. 采用扫描电镜、拉伸、三点弯曲和透光率试验等对其结构、力学和透光性进行了分析和表征. 结果表明: 超细纤维与大豆分离蛋白基体具有良好的界面相互作用; 超细纤维对复合材料起到了增强增韧的效果. 而且, 复合膜具有良好的透光率. 即使超细纤维质量分数达到13%, 该膜在700 nm波长处的透光率仍然可以达到77%. 相似文献
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利用激光诱导沉积的方法直接在光纤端面沉积了银纳米膜,并用SERS光谱监测了这一沉积过程,在光纤端面上生成的银膜出现了“年轮”状宏观形貌,这种形貌与激光在光纤中的干涉与衍射条纹分布相一致,证明了这种现象是由激光诱导反应引发的. 结合实验结果进一步讨论了银纳米膜的形成机理. 在光纤上沉积的银纳米膜作为光纤SERS传感器的基底与其它制备基底的方法比较也具有实验操作简便,耗时短,重现性好,SERS增强效果强等诸多优点,是一种非常好的制备光纤SERS传感器基底的方法. 相似文献
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Ahmed M. Donia Asem A. Atia Hassnaa M. Abd El-Latif 《Journal of Dispersion Science and Technology》2014,35(3):380-389
Cellulose was modified via chlorination using phosphorous oxychloride followed by functionalization with amine and thiol moieties. The obtained modified cellulose samples were investigated by means of FTIR, TGA, TEM, and nitrogen-adsorption surface area (BET). The BET measurements showed a remarkable increase in the surface area of Cell-N-S (477.7 m2/g) and Cell-N (706 m2/g). The resins gave an uptake capacities of 38 and 7.2mmol/g for Cell-N-S and Cell-N, respectively toward Hg(II) from its solutions. These values are considered much better compared with other reported resins. Regeneration of the resins was achieved effectively using acidified thiourea. 相似文献
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《高分子学报》2015,(8)
将不同维度纳米填料同时复合,采用纵向氧化切割MWCNTs法制得不同含量比的氧化石墨烯纳米带-碳纳米管(GONRs-CNTs)2种维度纳米材料复合体,随后将上述填料加入到TPU基体中制得GONRsCNTs/TPU复合材料薄膜.采用FTIR、XRD、TG、XPS、TEM和FE-SEM研究了不同反应条件下所得GONRsCNTs复合体的结构及性能,并结合复合材料薄膜的氧气透过率和拉伸测试以及表面形貌观察,研究了GONRs与CNTs的协同作用、二者的含量比对TPU复合材料薄膜阻隔和力学性能的影响.研究表明,GONRs与CNTs的协同效应明显优于MWCNTs,同时当所加GONRs-CNTs复合体中GONRs与CNTs的含量比约为67∶33时,GONRs-CNTs/TPU复合材料薄膜的氧气透过率和拉伸强度相比纯TPU薄膜分别降低51.3%和提高29.3%,阻隔性能和力学性能均得到明显改善. 相似文献