反应沉淀法制备阿奇霉素药物超微粉体

利用反应沉淀法进行了阿奇霉素微粉化的实验研究,考察了NaOH溶液浓度、搅拌速度、搅拌时间和反应温度等因素对产品粒度、形貌、分散性及收率的影响. 分别采用扫描电镜(SEM)、比表面分析仪、X射线衍射仪(XRD)和红外光谱仪(FT-IR)对产品进行了分析与表征,并对微粉化产品和原料药进行了溶出性能研究. 实验结果表明,利用此方法可以制备得到平均粒径约为413 nm的无定型阿奇霉素超微粉体,与原料药相比,微粉化的阿奇霉素粉体比表面积增加了约27倍,相应地,药物的溶出性能较原料药明显改善.     

醇解法合成锥形氧化锌纳米粉体

采用非水解法予150℃在乙二醇溶漳中合成了氧化锌粉体,用X射线衍射、透射电子显微镜和Fourier红外光谱对其进行了表征.结果表明:在乙二醇溶液中,可在较低的温度(150℃)制备出锥形纳米氧化锌粉体.所合成的纳米氧化锌以取向黏附的方式沿(002)方向进行择向生长,并呈现出强烈的紫外发射现象.     

反溶剂重结晶法制备青蒿素超细粉体

采用反溶剂重结晶法进行了青蒿素超细粉体的制备研究。以乙醇为溶剂,水为反溶剂,系统考察了药用辅料类型、反溶剂溶剂体积比、药物溶液浓度和混合强度对产品颗粒形貌和大小的影响。结果表明,辅料羟丙甲纤维素(HPMC)与聚乙烯吡咯烷酮 (PVP)联用可有效控制颗粒形貌,反溶剂溶剂体积比为20,青蒿素乙醇溶液浓度为20 mg·ml^-1,搅拌转速为8000 r·min^-1时,浆料中可得到平均短径0.84 μm、长径3 μm的针状颗粒,此浆料经喷雾干燥可得到粒径为2～3 μm的类球形粉体颗粒。进一步采用红外光谱、X射线衍射、差热分析、比表面积测试对原料药及产品的特性进行了表征,结果显示,青蒿素经反溶剂重结晶过程与辅料HPMC间产生一定的氢键作用,超细粉体产品的结晶度及熔点降低,比表面积增至原料药的26.4倍。体外溶出测试结果表明,青蒿素超细粉体的溶出速率远优于原料药,超细药物粉体15 min即可溶出88.3%,而同期原料药的溶出度仅为2.1%。     

沉淀溶出法制备纳米钛酸锌粉体

就纳米钛酸锌（ＺｎＴｉＯ３）粉体的沉淀溶出法制备条件进行了探讨,发现在６００℃煅烧１ｈ,即可制得氧化锌－钛酸锌复合粉体,其粒径２０～５０ｎｍ;将复合粉体中过剩的氧化锌溶出,继续在７００℃于马弗炉内煅烧１ｈ．能得到晶型较好的白色球状钛酸锌粉体,粒径约３０～６０ｎｍ。     

纳米ZnO-TiO2复合粉体的制备及抗菌性能的研究

目的:制备纳米级的ZnO-TiO2复合粉体,研究纳米ZnO-TiO2与单用纳米TiO2和纳米ZnO两种抗菌剂的抗菌能力。方法:本实验以ZnCl2和TiCl4为原料制备纳米级的ZnO-TiO2复合粉体,再选择了大肠杆菌和金黄色葡萄球菌为代表菌株,采用了纸片扩散法,对纳米ZnO-TiO2复合粉体抗菌剂进行了抗菌性研究,并与单用纳米TiO2和纳米ZnO两种抗菌剂抗菌性能进行比较。结果表明:纳米ZnO-TiO2复合粉体抗菌剂对代表菌株表现出比单用纳米ZnO或TiO2抗菌剂有更好的抗菌能力。在此基础上对相关抗菌剂的抗菌机理进行了分析讨论。     

碳酸钙／二氧化硅纳微复合粒子的高能球磨制备

采用高能球磨法制备了碳酸钙(纳米)/二氧化硅(微米)复合粒子.用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、能谱分析仪(EDS)和傅里叶变换红外光谱仪(FT-IR)研究了球磨过程中复合粉体的相组成和微观组织;对碳酸钙/二氧化硅复合粒子的粒径、形态、结构进行了测定与表征.结果表明随着球磨时间的延长,复合粉体在强烈的冲击、挤压作用下逐渐细化和均匀化;球磨240 min可形成结合紧密的碳酸钙/二氧化硅复合粒子,并使之球形化;纳米碳酸钙均匀复合于二氧化硅的表面及其空隙,复合过程中没有产生新物质;强烈的机械力作用,使纳米碳酸钙表面晶体结构发生畸变,颗粒表面无定形化程度增加.     

二氧化铈/氧化铝纳米复合粉体的制备及抗紫外线性能研究

紫外线对人类的危害已经引起人们的广泛关注,研制各种抗紫外线材料已成为人们研究的热点之一。为了弥补单一无机纳米粉体对某一波段紫外线屏蔽不佳的缺陷,以硝酸铈和硝酸铝为原料,采用超声-沉淀法制备了二氧化铈/氧化铝纳米复合粉体。研究了铈与铝物质的量比、煅烧温度、干燥方式对二氧化铈/氧化铝纳米复合粉体对紫外线吸收性能的影响。通过实验确定了超声-沉淀法制备二氧化铈/氧化铝纳米复合粉体的最佳工艺条件。采用热重-差热分析仪(TG/DTA)、X射线衍射仪(XRD)、紫外-可见光分光光度计(UV-Vis)以及激光粒度仪等对复合粉体的性能进行了表征。结果表明:在最佳工艺条件下制得的二氧化铈/氧化铝纳米复合粉体,属于原子级混合,其对紫外线的吸收性能优于二氧化铈、氧化铝任何一种单一粉体。     

1-脱氧野尻霉素控释微丸的制备工艺优化及其药动学研究

1-脱氧野尻霉素控释微丸采用挤出滚圆和流化床方法进行制备。首先使用羟丙基甲基纤维素和微晶纤维素等辅料制备分散体、丸芯，再使用羟丙基甲基纳米纤维素邻苯二甲酸酯作为主要包衣材料进行包衣，并装入胶囊。采用SEM观察微丸的微观形态，以及测定其产率、脆碎度、密度、水分含量和粒径分布等物理性质，研究结果显示微丸性质符合中国药典标准规定。在体外释药试验中，溶出介质和放置方式对药物释放无显著影响，释放过程符合Baker-Lonsdale模型。对比研究1-脱氧野尻霉素原料药、分散体微丸和控释微丸在比格犬体内的控释特性，结果表明：与1-脱氧野尻霉素原料药相比，分散体微丸和控释微丸分别使1-脱氧野尻霉素的生物利用度提高了183.37%和243.87%。此外，1-脱氧野尻霉素控释微丸的体内-体外研究的相关性分析可知体外溶出和体内吸收之间呈现良好的线性关系。     

Al2O3/Fe纳米复合粉体的制备及其陶瓷的性能研究

以纳米α-Al2O3和Fe(NO3)3·9H2O为原料,采用非均相沉淀法制备了Fe包裹Al2O3的纳米复合粉体.经XRD、SEM分析发现:复合粉体前驱体经500 ℃焙烧,在H2中700 ℃还原可以得到纳米Fe包裹Al2O3的纳米复合粉体.粉体分散良好,Al2O3表面的纳米Fe粒子呈非连续状态,颗粒为球形,尺寸为30 nm左右,分布均匀.将复合粉体在热压下(30 MPa)烧结获得Al2O3/Fe复合陶瓷,当加入5mol%Fe时,陶瓷的热压烧结温度比单相Al2O3陶瓷降低将近100 ℃.含量为10mol%Fe的陶瓷样品在1500 ℃热压烧结后,断裂韧性可达到5.62 MPa,与相同条件下烧结的单相Al2O3陶瓷(KIc=3.57 MPa)相比提高了近57%.     

SLS用纳米羟基磷灰石/聚酰胺6复合粉体的制备及粉体性能分析

采用高温高压溶剂沉淀法制备出纳米羟基磷灰石/聚酰胺6(n-HAP/PA6)复合粉体。通过扫描电子显微镜(SEM)、示差扫描量热法(DSC)和X-射线衍射(XRD)对粉体的微观形貌、热性能和结构进行分析;通过对粉体粒径及分布、压缩度和休止角测试,讨论了粉体的流动性能。结果表明:制备出的粉体由蓬松多孔结构变为光滑致密的近球形颗粒;随着n-HAP含量的增加,n-HAP/PA6复合粉体的熔融焓逐渐降低,有助于降低选择性激光烧结(SLS)扫描功率;成功实现了对粉体粒径的控制,当n-HAP含量为10%时粒径达到29.68μm;压缩度和休止角的降低充分表明,复合粉体中n-HAP含量为10%时所制备的粉体流动性最好。     

载阿奇霉素-鼠李糖脂胶束制备工艺优化及性能表征

采用薄膜水化法制备载阿奇霉素-鼠李糖脂(AZI-RHL)胶束，以包封率、载药量为评价指标，通过单因素试验和正交试验优化制备工艺，并考察其理化性质。制备载药胶束前先测定RHL水溶液的临界胶束浓度(CMC)。结果表明，RHL水溶液的CMC值约为0.25 mg/mL。优化后的最佳制备工艺条件为：RHL投料量100 mg，甲醇用量12 mL，搅拌时长20 min。在此条件下制备的AZI-RHL胶束呈球形，水动力学直径为136.3±68.5 nm，Zeta电位为-23.1±6.8 mV，包封率为80.34%±0.60%，载药量为19.42%±0.48%。红外光谱证明AZI包埋在胶束中。体外释放试验表明AZI-RHL胶束具有一定的缓释作用，其体外累计释放曲线符合Ritger-Peppas方程，释放药物以Fick扩散为主。综上所述，AZI-RHL胶束的制备工艺稳定可靠，胶束粒径小，且包封率、载药量高，是一种有潜力的新型制剂。     

纳米降凝剂在含蜡原油中的应用

总结了传统降凝剂在含蜡原油改性过程中存在的局限性以及纳米材料的特殊效应。分析了纳米降凝剂在含蜡原油降凝改性工艺中的优越性:纳米降凝剂削弱了蜡晶的结构强度,显著改善了含蜡原油的低温流动性,其降凝改性效果明显优于传统降凝剂,动、静态时效稳定性变好,抗剪切性提高。概述了目前纳米降凝剂在含蜡原油管道中的应用情况。     

聚吡咯对五氧化二钒干凝胶插层行为研究

本文采用分散直接插层法使聚吡咯(PPY)嵌入五氧化二钒(V2O5)凝胶层间。并通过X射线衍射(XRD)、红外光谱(FI-IR)和多点氮气吸附法(BET/N2)等测试手段对其进行分析,证明了PPY确实进入了五氧化二钒(V2O5)干凝胶的层间,为不溶性导电高聚物的插层提供了一条新的途径。     

Facile synthesis of an up-conversion luminescent and mesoporous Gd2O3 : Er3+@nSiO2@mSiO2 nanocomposite as a drug carrier

In this paper, we report the facile synthesis of a bifunctional inorganic nanocomposite which is composed of core-shell structured mesoporous silica coated with up-conversion Gd2O3?:?Er3+ particles. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption, and photoluminescence (PL) spectra were used to characterize the samples. The results indicate that the nanocomposite with general 50 nm shell thickness and 300 nm core size shows typical ordered mesoporous characteristics (2.3 nm) and has spherical morphology with smooth surface and narrow size distribution. The bifunctional system shows unique green up-conversion emission under 980 nm NIR laser excitation even after loading with drug molecules. In addition, biocompatibility tests on L929 fibroblast cells using an MTT assay reveals low cytotoxicity of the system. Drug release tests suggest that the nanocomposite has a controlled drug release property with ibuprofen (IBU) as the model drug. Interestingly, the up-conversion emission intensity of the bifunctional carrier increases with the released amount of model drug, thus allowing the release process to be monitored and tracked by the change of up-conversion luminescence intensity. This composite can potentially act as a functional drug carrier system.     

Phenolic foams toughened with crosslinked poly (n‐butyl acrylate)/silica core‐shell nanocomposite particles

A new type of crosslinked poly (n‐butyl acrylate) (PBA)/silica core‐shell nanocomposite particles was adopted as toughening agent to improve the mechanical properties of phenolic foams. The effects of the nanocomposite particles on the structures and properties of lightweight phenolic foams were investigated. SEM result showed that the addition of a small quantity of the nanocomposite particles can significantly enhance the structural homogeneity of phenolic foams. Thermalgravimetric analysis result suggested that the incorporation of the nanocomposite particles did not affect the thermal stability of the toughened phenolic foams. The flexural strength, compressive strength, and elastic modulus of the phenolic foams increased distinctively after the addition of the nanocomposite particles, the maximum values of which increased by 36.0%, 42.9%, and 32.3%, respectively. In this study, the optimum dosage of the nanocomposite particles is 0.03 phr in the modified phenolic foams. Moreover, the influence on the flammability of phenolic foams by toughening can almost be neglected. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42590.     

Synthesis of mesoporous cobalt ferrite/hydroxyapatite core-shell nanocomposite for magnetic hyperthermia and drug release applications

In this study, cobalt ferrite/hydroxyapatite nanocomposite was developed by a new approach to design a uniform core-shell combination. The prepared powders were characterized by different techniques such as Brunauer–Emmett–Teller (BET) analyses, transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR), Vibrating-sample magnetometer (VSM), and field emission scanning electron microscopy (FESEM). TEM micrographs showed the formation of a uniform core/shell structure with a particle size of about 85$\pm 65$ nm. The controlled drug release experiments showed that the samples have a good drug loading capability and controlled delivery ability up to 50 h. Moreover, with different magnetic fields or different cobalt ferrite ratios to hydroxyapatite, it is possible to manipulate the amount of produced heat, making this composite promising for various kinds of magnetic hyperthermia-based treatment. Cytotoxicity of the nanocomposite was evaluated by MTT assay using MG63 cells. MTT and VSM results revealed that incorporating hydroxyapatite on cobalt ferrite nanoparticles' surface significantly increases cell compatibility, whereas it reduces magnetization saturation. The results suggest that cobalt ferrite/hydroxyapatite nanocomposite with multifunctionality and uniform structure has a great capability to be applied for medical uses.     

Improved Photocatalytic Activity Using Ternary Au-ZnO/rGO Nanocomposite

In the present study, ternary Au-ZnO/rGO nanocomposite was prepared using a modified polyol protocol. The ternary structure was attained by deposition of both gold nanoparticles (AuNPs) and ZnO NPs on the rGO surface. No surfactants or ligands are used in this chemical process. On the other hand, 1,3-propanediol was used as solvent, reducing agent and surfactant to ensure the formation of NPs and inhibit particles accumulation. The XRD data confirm the successful formation of the three materials and the high crystallinity of the as-prepared sample. Moreover, the XPS measurements confirmed the high purity of the nanocomposite. TEM images show the formation of ternary Au/ZnO/rGO nanostructure. However, Au and ZnO NPs exhibited spherical shape with an average size of 20 nm and homogeneously distribution onto the rGO surface. The ternary Au-ZnO/rGO nanocomposite exhibited optical response in both UV and visible region due to the plasmonic properties of AuNPs. The BET data revealed an increase of the surface area of Au-ZnO/rGO nanocomposite compared to bare ZnO and hybrid Au-ZnO NPs which render it a promising system for high photocatalytic activity. The preliminary photodegradation measurements against MB molecules prove the high performance of the ternary Au-ZnO/rGO nanocomposite to decompose pollutant molecules compared to bare ZnO. The observed photocatalytic activity enhancement could be attributed to the apport given by both plasmonic properties of AuNPs and the high surface area of rGO.

     

流化床CVD法原位合成CNTs-Ni-TiO2及其光催化性能

采用柠檬酸修饰溶胶-凝胶法制备NiO-TiO₂催化剂,然后于流化床反应器中直接在NiO-TiO₂表面原位生长多壁碳纳米管,制备出CNTs-Ni-TiO₂复合光催化剂。采用XRD、SEM、TG、BET、PL荧光光谱等方法对制备的样品进行了表征,以亚甲基蓝降解为模型反应,考察了复合催化剂在紫外线下的光催化性能。结果表明,在NiO含量为5%的NiO-TiO₂催化剂上生长CNTs后得到的CNTs-Ni-TiO₂复合材料具有较高的光催化活性。     

Preparation and characterization of porous acrylate terpolymer nanocomposite for removal of diesel oil from artificial seawater

The present work deals with the preparation of magnetic acrylate terpolymer nanocomposite by emulsion polymerization. This nanocomposite was applied for the removal of diesel oil from artificial seawater by magnetic separation. Magnetic terpolymer nanocomposite was characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Specific surface area and pore size distribution were measured by the Brunauer–Emmett–Teller (BET) method. Contact angle (CA) measurement showed superhydrophobic properties of magnetic acrylate nanocomposite. Kinetics and isothermal studies indicate that oil sorption fits the second-order kinetic model and the Langmuir isotherm. Magnetic acrylate terpolymer can be regenerated for six cycles.