共查询到19条相似文献,搜索用时 234 毫秒
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以壳聚糖为原料,经羧甲基化、纳米化与Ca~(2+)、Zn~(2+)复合制备出纳米羧甲基壳聚糖含钙、锌复合物,采用红外光谱、X射线衍射光谱、扫描电镜等光学手段对样品进行结构表征,考察了复合物的凝血、止血性能。结果表明:纳米羧甲基壳聚糖结构中含有磷酸盐结构,Ca/Zn-纳米羧甲基壳聚糖结构中含有Ca~(2+)与Zn~(2+),Ca~(2+)和Zn~(2+)与纳米羧甲基壳聚糖成功复合;复合物的结晶性下降、溶解性提高、形貌均匀圆整,且凝血、止血时间明显缩短;Ca-纳米羧甲基壳聚糖比Zn-纳米羧甲基壳聚糖结构更稳定,凝血、止血效果更好。 相似文献
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以壳聚糖(CTS)与硫氰酸铵和氯乙酸反应,合成了带有硫脲基和羧基双官能团的中间产物,再经戊二醛交联,制备了水不溶性的可用于处理含金属废水的颗粒状树脂.用FT-IR进行了表征,表明-HN-C(S)-NH-CH2-COOH基团接枝到CTS链上并形成交联.吸附实验表明,该树脂对Cd2 的吸附量(2.248mmol·g-1)比Mg2 (1.035mm0l·g-1)高得多.再生3次后的树脂仍然具有良好的吸附性能. 相似文献
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以壳聚糖为原料,在碱性条件下合成了羧甲基壳聚糖,考察了其对稀土离子Eu3 的吸附性能.讨论了时间,溶液的酸度、初始离子浓度、羧甲基取代度及离子强度对吸附性能的影响.发现羧甲基壳聚糖对Eu3 有较强的吸附性,吸附性满足Langmir等温式. 相似文献
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为了提高壳聚糖的水溶性及其止血方面的性能,将壳聚糖(CS)进行羧甲基化改性,并引入具有抗菌作用的Ag+和TiO2,制备出羧甲基壳聚糖复合止血材料。首先,在壳聚糖中引入羧甲基,制得羧甲基壳聚糖(CMCS),之后向其中引入Ag+和TiO2,分别制备出Ag+-CMCS、TiO2-CMCS和Ag+-TiO2-CMCS复合材料。然后,采用FTIR、XRD、SEM等手段对复合材料的结构进行表征。最后,对复合物的凝血、止血性能进行了测试。实验结果表明:改性后的羧甲基壳聚糖的IR图谱在3 423 cm-1和1 380 cm-1处出现了羧甲基壳聚糖钠盐的特征吸收峰。改性后的羧甲基壳聚糖在XRD图谱中表现出了金属晶态。CMCS的粒径为14.8 nm左右,Ag+粒径为143.5 nm左右,纳米TiO2的粒径为267.2 nm左右,且三者分散的很均匀。Ag+-TiO2-CMCS的凝血、止血效果要优于Ag+-CMCS和TiO2-CMCS,同时Ag+-CMCS和TiO2-CMCS的凝血、止血效果要优于CMCS。 相似文献
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在最佳反应条件下制备过氧化氢对壳聚糖的降解产物,通过测定原料及降解产物(Mw=1 500~166.53 kDa)的氮、碳含量,分析它们的红外光谱、核磁共振碳谱、X射线衍射谱及圆二色谱,考察各产物是否保持其天然结构。结果表明:各降解产物与原料的碳含量,氮含量及脱乙酰度的最大相对偏差分别为2.4%,2.3%与6.9%,且后两者随着反应时间的延长而减小;各降解样品的红外光谱及核磁共振碳谱与原料壳聚糖的相似,说明降解过程几乎不改变原料的化学结构;经相同方法处理过的原料及降解产物在2θ=10.4°和19.8°处均存在X射线衍射峰,在210 nm处均存在一个负的圆二吸收峰,表明产物的固态结构与其在溶液中的构象均没有发生变化。说明在优化的降解条件下过氧化氢氧化降解没有改变壳聚糖的天然结构。 相似文献
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采用光聚合技术成功制备了羧甲基壳聚糖(CSC)、丙烯酰胺(AM)、丙烯酸(AA)的三元接枝共聚物,即壳聚糖基重金属捕集絮凝剂CSC-P(AM-AA)。为了证明接枝共聚产物的成功制备和表征其结构特征,采用红外光谱(IR)、X射线衍射(XRD)、差热-热重分析(TG-DSC)、扫描电镜(SEM)对其进行表征,结果表明成功制备出羧甲基壳聚糖的接枝共聚物CSC-P(AM-AA),且具有较好的溶解性;由于羧甲基壳聚糖的接枝改性使得CSC-P(AM-AA)具有与P(AM-AA)显著不同的结构特征。同时絮凝实验证明其具有较好的重金属螯合捕集效果,在pH为8、投加量为8 mg·L-1、转速为150 r·min-1时,CSC-P(AM-AA)对Cu2+的最佳去除率为87.0%。 相似文献
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壳聚糖是一种富含氨基和羟基的天然高分子聚合物,易成膜,膜的机械性能、透光率好,且膜的表面平整光滑,对叶绿素有较高的富集能力,平衡态时叶绿素在壳聚糖膜和水相两相间的分配系数为9090,重现性好,可以研制成固相微萃取薄膜用于叶绿素的分析。磁力搅拌萃取叶绿素,壳聚糖膜可在80 min内达到平衡,用5%NaOH超声洗脱30 min内可以洗脱干净。红外光谱和X射线衍射谱图表明萃取叶绿素之后的壳聚糖分子中分子内或分子间的氢键作用力大大减弱,可能是壳聚糖分子中的大量氨基和羟基在萃取叶绿素的过程中起关键作用。 相似文献
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Willian Garcia Birolli Jorge Augusto de Moura DelezukSérgio Paulo Campana-Filho 《Applied Acoustics》2016
This paper discusses the production of chitosan by applying high intensity ultrasound irradiation to alpha-chitin suspended in 40% aqueous sodium hydroxide. The average degree of acetylation (DA) of chitosan was determined by 1H NMR spectroscopy and titrimetry while its viscosity average molecular weight (Mv) was calculated from the intrinsic viscosity as determined by capillary viscometry. The results show that fully acid-soluble chitosans (DA < 32%; 100,000 g/mol ? Mv ? 200,000 g/mol) are produced at very high yield (>95%) by applying non-isothermal ultrasound-assisted N-deacetylation process to alpha-chitin suspension (44 mg/mL). It is also shown that such a process is more efficient than thermochemical N-deacetylation, even being carried out at a lower temperature due to the effects of high intensity ultrasound irradiation. 相似文献
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One-pot synthesis of a chitosan-based hydrogel as a potential device for magnetic biomaterial 总被引:1,自引:0,他引:1
Alexandre T. Paulino Marcos R. Guilherme Antonio G.B. Pereira Elias B. Tambourgi 《Journal of magnetism and magnetic materials》2009,321(17):2636-2642
This describes the cross-linking/co-polymerization reaction of chitosan (CS), acrylic acid (AAc), and N, N′-methylenebisacrylamide (MBA) in the presence of citrate-covered-γ-Fe2O3 nanoparticules. A gelling process was verified by means of spectroscopic methods; Fourier transform infrared (FT-IR) and solid-state 13C-CP/MAS nuclear magnetic resonance (NMR). The corresponding signals of the gelling process, in the 13C NMR spectra, for the magnetic hydrogel were shifted to lower values due to embedding of the citrate-covered-γ-Fe2O3 nanoparticules. The X-ray diffraction (XRD) confirmed that the crystallinity of the magnetic hydrogel exhibited a different crystalline structure to that without magnetic properties. The Mössbauer and magnetization analysis revealed that the magnetic hydrogel displays a high lattice strain, due to bonded iron atom covalence and superparamagnetism. From scanning electronic microscope (SEM) micrographs, no separation phase coexists between the magnetic nanoparticules and cross-linked hydrogel, indicating an excellent dispersion throughout the hydrogel. The swelling rate was dependent on the cross-linking degree of the hydrogel and ionic strength of the aqueous solution. 相似文献
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利用对离子复合凝聚法,以EDTA为对离子,戊二醛为交联剂,壳聚糖(CS)为原料制备了CS纳米粒子。用动力学光散射分析(DLS)、透射电子显微镜(TEM)、FTIR对合成的CS纳米粒子进行了表征。表征结果表明,采用该方法合成的CS纳米粒子约为70nm,CS和EDTA通过电荷吸引凝聚成纳米粒子。 相似文献
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壳聚糖与不同金属锌盐配位的红外光谱研究 总被引:10,自引:0,他引:10
用壳聚糖和硫酸锌合成了一系列不同配比的配合物。通过对这些配合物红外光谱的分析和比较,考察了主要吸收峰随不同配比的变化规律,照发了它们的主要红外吸收峰,研究还表明,不同锌盐与壳聚糖形成的配合物有不同的配位环境。 相似文献
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Green synthesis of biocompatiable chitosan–graphene oxide hybrid nanosheet by ultrasonication method
Ultrasound-induced synthesis of chitosan-modified nano-scale graphene oxide (CS-NGO) hybrid nanosheets, which has great potential pharmaceutical applications, in supercritical CO2 without catalyst was presented for the first time. The preparation process does not require organic solvent and post-processing, and CO2 easily escapes from the product. The morphology and structure of the CS-NGO, characterized using scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis, confirms that it was combined via the amide linkage, and had excellent dispersibility and stability toward acidic and physiological aqueous solution, which implies that it could be used as a drug-carrier. The sonication power played a crucial role in inducing forming amidation, and the conversion rate increased with the sonication time. The mechanism of this reaction was explained. 相似文献
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Microwave-assisted covalent modification of graphene nanosheets with chitosan and its electrorheological characteristics 总被引:1,自引:0,他引:1
Huating HuXianbao Wang Jingchao WangFangming Liu Min ZhangChunhui Xu 《Applied Surface Science》2011,257(7):2637-2642
Biofunctionalization and manipulating of graphene nanosheets (GNS) are important for biomedical research and application. Chitosan (CS) modified graphene nanosheets have been successfully prepared under microwave irradiation in N,N-dimethylformamide medium, which involved the reaction between the carboxyl groups of graphene oxide nanosheets (GONS) and the amido groups of chitosan followed by the reduction of graphene oxide nanosheets into graphene nanosheets using hydrazine hydrate. The as-prepared graphene nanosheets-chitosan (GNS-CS) nanocomposites have been characterized by FTIR, TEM, FESEM, XRD and TG. The results showed that chitosan was covalently grafted onto the surface of graphene nanosheets via amido bonds. Solubility measurements indicated that the resultant nanocomposites dispersed well in aqueous acetic acid. Especially, the electrorheological (ER) properties of the GNS-CS nanocomposites have been investigated. It is believed that this new nanocomposites may be promising for biomedical applications. 相似文献