交联淀粉纳米晶的制备和性能

通过环氧氯丙烷与淀粉纳米晶表面羟基活性基团反应,制备交联淀粉纳米晶,并经傅里叶变换红外光谱、核磁共振氢谱、X射线衍射及扫描电镜等对其结构与形态进行表征。交联淀粉纳米晶在化学结构上变化不大,由交联反应形成的化学键仍为醚键,与淀粉纳米晶本身的化学键类似。交联淀粉纳米晶的结晶结构也基本不变,得到的是分散比较稳定的50nm左右的颗粒。而热性能分析表明,交联淀粉纳米晶的熔融温度略有提高。浸润性实验结果表明,交联淀粉纳米晶具有一定的疏水性,可在水、丙酮、二氯甲烷中均匀分散,但在乙酸乙酯中无法分散。交联淀粉纳米晶与聚丁二酸丁二醇酯复合材料的力学性能表明,当交联淀粉纳米晶含量为3%时,拉伸强度增加约11%,拉伸模量增加约13%,断裂伸长提高约10%,说明交联淀粉纳米晶可以增强、增韧聚丁二酸丁二醇酯。     

淀粉基碳包覆铁纳米胶囊的合成及其磁学性能

以淀粉为碳源，通过热解炭化铁／淀粉复合物，成功制备出碳包覆铁（Fe@C）纳米胶囊。在这一过程中淀粉有双重作用，既是碳源又是铁纳米颗粒的稳定剂。采用透射电镜、X射线衍射及振动样品磁强计研究了（Fe@C）纳米胶囊的结构和磁学性能。发现Fe@C纳米胶囊具有完美的铁核（bcc-Fe）／碳壳（石墨层片）包覆结构，其尺寸介于30nm～40nm之间；Fe@C纳米胶囊在室温下有低的剩磁比（Mr／Ms=0．11），表明它在室温下具有超顺磁性。     

羟基磷灰石/淀粉基复合生物材料

淀粉基(starch-based)材料是一类重要的生物降解聚合物,羟基磷灰石(HA)是人体骨骼的主要成分,以淀粉基材料为基体、以HA为增强材料的HA/淀粉基复合材料是一类新型的复合生物材料,其具有良好的生物相容性,在骨修复领域具有巨大的应用潜力.初步对该复合材料进行了归类,并介绍了其制备工艺、性能和应用等方面的研究近况,指出改进复合工艺、采用纳米级HA增强并进行表面改性是其发展趋势.     

淀粉颗粒聚集态结构研究进展

详述了淀粉颗粒中直链淀粉和支链淀粉的分子结构和分布位置,结晶结构及聚集态结构,以及颗粒的晶体结构与形状之间的关系等最新研究成果,同时对淀粉颗粒聚集态结构的研究方向提出展望。认为直链淀粉是分散在支链淀粉分子中且更集中于颗粒表面;颗粒表面比颗粒内部的支链淀粉分子具有更多的短支链。A型多晶淀粉比B型多晶淀粉具有更为松散的内部结构,因而后者对酸和酶具有更强的抗性。     

非层状纳米无机粒子/热塑性聚合物复合材料制备方法研究进展

纳米粒子由于十分容易聚集和团聚, 加之表面亲水性的纳米颗粒和表面憎水性的聚合物基体的相容性较差, 往往以较大的团聚体形式分散于聚合物基体树脂中, 导致复合材料的性能不佳。基于常规共混法的纳米颗粒/聚合物复合材料制备技术仍是重要的制备途径之一, 关键在于如何解决复合体系中纳米粒子的有效分散和利用问题。为此, 本文中针对非层状纳米无机粒子/热塑性聚合物复合材料的制备, 介绍了纳米无机粒子表面改性和纳米颗粒在热塑性聚合物中的分散技术方面的研究进展。      

水溶性NaYF4:Yb,Er纳米颗粒的溶剂热合成及其上转换发光性能

稀土上转换发光纳米材料具有极好的生物应用前景,但其应用的前提是能制备出水溶性、发光效率高的稀土纳米材料.以乙二醇为溶剂、稀土氯化物和NaP为反应物,采用简易的溶剂热法一步制备出水溶性的NaYF4:Yb,Er纳米颗粒.NaYF4:Yb,Er样品以粒径为25~40nm的球形颗粒为主,同时含有少量直径为25~40nm、长度为50～100nm的虫状纳米颗粒.该样品具有立方相结构,样品表面上的乙二醇配体使其能够很好地分散于水中.在980nm激光器激发下,NaYF4:Yb,Er纳米颗粒水溶液展现了强的黄绿色上转换发光.因此该样品拥有良好的生物应用潜力.     

交联β-环糊精聚合物/Fe3O4核壳结构复合纳米颗粒的制备和性能研究

以羧甲基-β-环糊精为表面修饰剂对Fe3O4纳米粒子进行包覆修饰,以环氧氯丙烷为交联剂,在β-环糊精的碱性溶液中通过Fe3O4纳米粒子表面进行的交联反应制备了交联β-环糊精聚合物/Fe3O4复合纳米颗粒.利用FTIR、XRD、TEM和TGA分剐对复合纳米颗粒的结构、形貌和尺寸进行了表征.结果表明,制备的复合纳米颗粒为近球形、核壳结构,粒径约为10～20nm,环糊精聚合物含量为29%,在水中的分散性良好.磁性能测试和包合性能测试表明,复合纳米颗粒为超顺磁性,对特定分子具有一定的包合能力,可用于靶向给药系统和特定物质分离的载体.     

生物素化普鲁兰多糖纳米颗粒制备与表征

合成生物素化普鲁兰多糖衍生物(BP),采用纳米沉淀法制备纳米颗粒(BPNs),考察制备条件对纳米颗粒性质影响,为进一步将其作为药物载体的研究提供基础.通过酯化反应将生物素羧基与普鲁兰多糖连接,生成的衍生物BP通过FI-IR和1H-NMR表征,取代度采用电感耦合等离子体光谱仪(ICP)确定;BPNs进行透射电镜、动态光散射仪和ζ电位仪表征与检测,颗粒表面生物素采用Quant*TagTM Biotin Kit生物素测定试剂盒测定.获得取代度21(BP1),46(BP2),81(BP3)3种衍生物,其中BP2和BP3能够制备纳米颗粒(LBPNs,HBPNs).纳米颗粒呈球形,表面光滑规整,平均粒径100～300nm,水中ζ电位在一17mV左右.制备过程中,粒径随BP浓度(10～50mg/ml)增加而增加((136.2±46.8)nm,(190.8±89.6)nm和(254.5±140.0)nm).调整水相组成为水:元水乙醇(v/v)1:1和1:2时粒径分别为(170.7±30.4)nm和(158.8±21.0)nm.HBPNs和LBPNs表面的生物素量为衍生物的(1.9±0.03)%和(2.0±0.04)%.生物素化普鲁兰多糖衍生物通过纳米沉淀法能制备出纳米颗粒,颗粒表面存在有生物素,颗粒性质受制备条件影响.     

核-壳式纳米Al2O3 / PS 复合粒子改性聚苯乙烯的选区激光烧结实验研究

针对纳米粒子易团聚的特点, 利用乳液聚合方法制备纳米Al₂O₃ / PS 复合粒子。用TEM、FTIR 对复合粒子结构进行了表征。结果表明, 所制备的复合粒子具备以纳米氧化铝为核、以聚苯乙烯为壳的核2壳式结构, 而且包覆层厚度大约为10～20 nm。用复合粒子改性选区激光烧结制备聚苯乙烯基纳米复合材料, 通过SEM 和FE2SEM 研究纳米复合材料烧结体的显微结构, 发现纳米粒子较好地分散在聚合物基体中, 且纳米氧化铝与聚合物基体之间的界面相容性和粘结性较好, 烧结体结构较致密。      

聚乙烯和纳米蒙脱土与淀粉共混改性研究进展

综述了近年来纳米蒙脱土和聚乙烯与淀粉共混改性制备可降解复合材料的方法和加工工艺。此外,还综述了淀粉的表面改性和相容剂加入、纳米蒙脱土的剥离和在基体树脂中的分散对共混复合材料的力学性能、热性能、耐水性能及材料的微观结构的影响。     

TiO2纳米微粒对淀粉粘合性能的促进作用

以粘合强力、断裂功以及断裂伸长为量化指标,通过轻浆粗纱法定量研究了T iO2纳米微粒对淀粉与聚酯、棉及聚酯/棉混纺纤维粘合性能的影响。实验结果表明,当这种微粒对淀粉的用量在0.15%~0.5%范围时,能够提高淀粉对上述三种纤维的粘合性能,并能改善淀粉浆液的黏度热稳定性。     

热塑性淀粉片材的制备及性能研究

利用双螺杆挤出机对玉米淀粉进行糊化处理,经干燥、粉碎后制得预糊化淀粉,以其为原料,添加甘油,PVA为增塑剂制备热塑性淀粉,经模压制备片材后,通过偏光显微镜分析了淀粉的糊化情况,研究了甘油含量和PVA含量变化对材料性能的影响。实验结果表明:甘油含量的增加会降低片材的抗拉强度,但升高其断裂伸长率;而增加了PVA的含量,材料抗拉强度和断裂伸长率均呈增长趋势。     

Naproxen Particle Design Using Porous Starch

Naproxen (Nap) was embedded in porous starch by preferential grinding, and we examined the physicochemical properties of these particles, including pore diameter, pore volume, and dissolution of naproxen. Porous starch (PS) particles made by preferential grinding with a Mechanofusion system had a higher content of naproxen than those made using the Mechanomill as determined using a mercury porosimeter. Neither sample showed any significant changes in crystallization state of naproxen in particles as determined by powder X-ray diffraction and differential scanning calorimetry (DSC). No interactions occurred between naproxen and porous starch due to preferential grinding as determined by powder X-ray diffraction and DSC. The dissolution rate of drug from particles prepared by preferential grinding was faster than that from physical mixtures.     

Naproxen Particle Design Using Porous Starch

Naproxen (Nap) was embedded in porous starch by preferential grinding, and we examined the physicochemical properties of these particles, including pore diameter, pore volume, and dissolution of naproxen. Porous starch (PS) particles made by preferential grinding with a Mechanofusion system had a higher content of naproxen than those made using the Mechanomill as determined using a mercury porosimeter. Neither sample showed any significant changes in crystallization state of naproxen in particles as determined by powder X-ray diffraction and differential scanning calorimetry (DSC). No interactions occurred between naproxen and porous starch due to preferential grinding as determined by powder X-ray diffraction and DSC. The dissolution rate of drug from particles prepared by preferential grinding was faster than that from physical mixtures.     

TiO2纳米微粒的溶胶-凝胶法制备及XRD分析

本文采用溶胶 凝胶法制备二氧化钛纳米微粒。用XRD分析了二氧化钛胶体经不同温度热处理后的晶粒粒径。分析表明温度在 4 73K时TiO2 微粒呈锐钛矿结构 ,粒径约为 5 5nm。在 6 73K以上TiO2 粒径迅速增大 ,微粒出现锐钛相与金红石相混晶结构。 973K时TiO2 微粒完全转化为金红石相。用晶界结构弛豫的观点解释粒径随热处理温度变化关系     

Hydrothermal synthesis of magnetite nanoparticles via sequential formation of iron hydroxide precipitates

A novel method for preparing fine magnetite nanoparticles without using any additives and organic solvents has been developed. In this method, a sequential precipitates formation method, ferrous and ferric hydroxides are not coprecipitated but sequentially formed in an alkaline solution, and then the resulting suspension is subjected to a hydrothermal treatment. The obtained magnetite nanoparticles were characterised through scanning electron microscopy observation and X-ray diffraction analysis, and the particle size and magnetic properties were measured with a dynamic light scattering particle size analyser and a superconducting quantum interference device magnetometer, respectively. In order to prepare fine magnetite nanoparticles with a uniform size, both the formation sequence of ferrous and ferric hydroxide precipitates and the supersaturation of ferric hydroxide in the solution were essential. The ferromagnetic magnetite nanoparticles with a median size 8.5?nm were relatively easily obtained in the formation process in which a ferric sulphate solution was rapidly poured into a suspension of ferrous hydroxide particles prepared beforehand using ferric chloride and sodium hydroxide, whereas the median size of magnetite nanoparticles prepared via conventional coprecipitation route was 38.6?nm.     

Investigation of magnetically enhanced swelling behaviour of superparamagnetic starch nanoparticles

The present study follows a novel strategy for the preparation of superparamagnetic nanoparticles of cross-linked starch impregnated homogeneously with nanosized iron oxide. The prepared magnetic nanoparticles were characterized by infra-red (FTIR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction and magnetization studies. The size of the magnetic polymeric particles was found to lie in the range of 20–80 nm, and they exhibited superparamagnetic properties. The particles were allowed to swell in phosphate buffer saline (PBS) and the influence of factors such as chemical composition of nanoparticles, pH and temperature of the swelling bath and applied magnetic field was investigated on the water intake capacity of the nanoparticles. The prepared nanoparticles showed potential to provide a possible option for controlled and targeted delivery of anticancer drugs, applying external magnetic field.     

PVA/淀粉单层和多层复合材料的制备和性能研究

利用流延成形的方法制备PVA/淀粉单层和多层复合薄膜,并通过硅溶胶对其进行改性,对其力学性能和亲水性能进行研究,通过扫描电镜（SEM）、傅里叶红外（FT-IR）等对其进行表征。FT-IR结果表明,SiO₂与淀粉或PVA间发生脱水缩合,分子链间产生交联,SiO₂含量越多,交联程度越大。通过薄膜拉伸断口的SEM分析,在多层结构中,SiO₂颗粒能起到更好的增强增韧效果,多层结构比单层结构有着更高的抗拉强度和断裂延伸率。     

PVA／Starch共混体系的形态,结构和性能

采用聚乙烯醇与淀粉共混的方法制备自然降解的淀粉塑料薄膜，对不同成分的薄膜进行了结构表征，ＳＥＭ观察。力学性能测定和不同条件下粘度测定及数据处理，在实验的基础上探讨了其形成机理。     

纸材料用淀粉接枝聚丙烯酰胺的制备与表征

以过硫酸铵为引发剂,制备了纸包装材料用淀粉接枝聚丙烯酰胺聚合物,并采用红外光谱仪、热重分析仪和扫描电子显微镜研究了聚丙烯酰胺、淀粉以及淀粉接枝聚丙烯酰胺聚合物的结构。通过红外光谱分析,确认淀粉已接枝上聚丙烯酰胺;通过热重分析,发现淀粉接枝聚丙烯酰胺比聚丙烯酰胺更稳定;通过扫描电镜分析,可知淀粉接枝聚丙烯酰胺是接枝在淀粉颗粒表面的,呈网状结构。