DEVELOPMENT OF MAGNETICALLY RESPONSIVE Fe3O4@C CORE/SHELL MICROSPHERES AS POTENTIAL VECTORS FOR DRUG-DELIVERY APPLICATIONS

NANO ◽  
2013 ◽  
Vol 08 (04) ◽  
pp. 1350039 ◽  
Author(s):  
WENJING YUAN ◽  
LING ZHU ◽  
PING CHEN ◽  
ANJIAN XIE ◽  
HUI ZHANG ◽  
...  

The Fe3O4@C core/shell microspheres were fabricated via a two-step process. Fe3O4 microspheres were firstly prepared, and Fe3O4@C core/shell microspheres were subsequently fabricated using glucose as a carbon source by a hydrothermal route, in which the thickness of the carbon coating was about 20 nm. The resulting products were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectra (FTIR). The Nitrogen adsorption–desorption isotherms reveal their mesoporous structure and larger BET surface area (62.3 m2g-1). The Fe3O4@C core/shell microspheres possess ferromagnetism and high saturation magnetization (39.2 emu ⋅ g-1). Bovine hemoglobin (BHb) was used as a model protein to test the adsorption and desorption properties of the Fe3O4@C core/shell microspheres. The capacity for BHb adsorption was more than 71.3 mg/g. According to the values obtained in the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay the Fe3O4@C core/shell microspheres show a low toxicity. Therefore, the prepared Fe3O4@C core/shell microspheres are of great significance for guided site-specific drug delivery.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jinfeng Liu ◽  
Haiyan Li ◽  
Qiuye Li ◽  
Xiaodong Wang ◽  
Min Zhang ◽  
...  

Mesoporous CeOx/TiO2nanoparticles have been successfully synthesized using titanate nanotubes as precursor through the hydrothermal-calcination method. The as-prepared materials were characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), UV-vis diffuse reflectance spectra and nitrogen adsorption-desorption isotherm analysis. All the obtained CeOx/TiO2materials exhibit anatase phase. Ce element existed in two valance states of Ce3+and Ce4+. Introduction of Ce species can effectively extend the spectral response from UV to visible light region. N2adsorption-desorption analysis revealed that all the samples belong to mesoporous structure and have large BET surface area compared with P25. The CeOx/TiO2nanoparticles showed excellent photocatalytic activity in the degradation of MB under visible light irradiation.


2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.


Author(s):  
T. F. Kouznetsova ◽  
A. I. Ivanets ◽  
J. D. Sauka

Titania-silica membranes on a porous quartz substrate are prepared by its direct contact with metal silicate sol at various Ti/Si ratios in the conditions of coagel sedimentation and presence of cetylpyridinium chloride. The study of textural and adsorption properties of membranes is conducted by low-temperature nitrogen adsorption-desorption, including methods of t-plots and DFT theory. It was shown that obtained membranes have mesoporous structure with the specific surface area and pore hydraulic diameter varied in intervals of 64–217 m2 /g and 4–11 nm, respectively. Developed values of surface area remain up to molar ratio of Ti/Si = 50/50.


2011 ◽  
Vol 194-196 ◽  
pp. 389-392
Author(s):  
Ling Li ◽  
Hong Liang Li ◽  
Ying Chun Zhu ◽  
Ai Ping Fu ◽  
Yong Wan ◽  
...  

Polystyrene (PS) spheres encapsulated core-shell composites of SiO2or TiO2nanoparticles were prepared by the spray drying technique and hollow spheres of SiO2or TiO2nanoparticles were then derived by removing the PS cores with calcinations. The PS spheres were dispersed into the SiO2or TiO2colloids, forming a suspension and then the suspensions were sprayed to form micrometer-sized droplets, as the droplets rush through the drying chamber, the PS spheres were encapsulated into the core of SiO2or TiO2particles due to the high temperatures and the instant evaporation, obtaining PS@SiO2, PS@TiO2or PS@SiO2/TiO2core-shell composites. After removing the PS core by calcination at 550°C, SiO2or TiO2hollow spheres were then derived. The influence of drying temperature, the concentration of the SiO2or TiO2particles and the ratio of PS sphere to the particles on the structures and specific surface area of the hollow spheres were studied with scanning electron microscopy (SEM) and nitrogen adsorption-desorption measurements.


2018 ◽  
Vol 921 ◽  
pp. 60-64
Author(s):  
Ke Xun Li ◽  
Jiang Jiang Ma ◽  
Jie Zhang ◽  
Kun Jia ◽  
Bi Cheng Zhou ◽  
...  

In this paper, we reported on the preparation of porous materials via a reaction under Autogenic Pressure at Elevated Temperature (RAPET) at 700°Cusing natural product and alkoxides as precursors. The RAPET is a new simple efficient method to prepare inorganic materials. The porous carbon and its composite materials were prepared via the method of RAPET using natural products such as sweet potato, coriander, the absorbent cotton and viscose fiber doped by tetrabutyl titanate (TBOT) and tetraethoxysilane (TEOS). The reaction temperature of RAPET was 700°C. The carbon and its composites were studied with scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. The BET surface area of the materials are different from 4m2/g to 405m2/g. The XRD investigation indicates that the phases of the TiO2 in the carbon/TiO2 composites are anatase. The materials show a certain charge-discharge performance.


2014 ◽  
Vol 962-965 ◽  
pp. 890-898
Author(s):  
Jin Ping Li ◽  
Da Zhen Tang ◽  
Ting Xu Yu ◽  
Gang Sun

Pore structure characteristics and the effect of lithotype and maceral on pore for three types of high-volatile bituminous coals from Binchang area were investigated by combined low-temperature nitrogen adsorption/desorption, nuclear magnetic resonance (NMR), scanning electron microscope (SEM) and maceral analysis. The low temperature N2 adsorption/desorption test results show that: micropores are more abundant than transitional pores with high BET surface area; two types of pore structures can be identified by adsorption/desorption isotherms; Pore morphology is mainly represented by well-connected, ink-bottled, cylindrical and parallel plate pores. NMR T2 distributions at full saturated condition are apparent or less obvious trimodal and three types of T2 distributions are identified; Seepage pores are better developed when compared with the middle-high rank coal. Further research found that the three coal lithotypes are featured by remarkably different pore structure characteristics and maceral contents of coal are linearly correlated to some of pore structure parameters.


2015 ◽  
Vol 18 (1) ◽  
Author(s):  
Zhaoqi Pan ◽  
Junyu Zeng ◽  
Bingyan Lan ◽  
Laisheng Li

AbstractArgentum-loaded MCM-41 (Ag/MCM-41) was synthesized successfully by a hydrothermal method and used as a catalyst for the ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution. Ag/MCM-41 was characterized by low angle X-ray diffraction (XRD), nitrogen adsorption-desorption and transmission electron microscopy (TEM). Characterizations suggest that the prepared samples retained a highly regulated mesopores of hexagonal structure and a high BET surface area. The influences of argentum content, initial pH, reaction temperature on the catalytic ozonation were also evaluated. Ag/MCM-41/O


2020 ◽  
Vol 42 (4) ◽  
pp. 550-550
Author(s):  
Houria Rezala Houria Rezala ◽  
Houda Douba Houda Douba ◽  
Horiya Boukhatem and Amaya Romero Horiya Boukhatem and Amaya Romero

A purified raw montmorillonite and hydroxy-aluminum pillared montmorillonite have been prepared from a natural bentonite from Maghnia, Algeria. These materials have been analyzed by X-ray fluorescence spectroscopy, X-ray diffraction, Infrared spectroscopy and nitrogen adsorption-desorption measurement. The pillared montmorillonite provided a certain increase of interlayer basal spacing and BET surface area and consequently the improvement of its capacities adsorption and decolorization of Methylene Blue. The adsorption properties of these materials were studied as a function of contact time, solution pH, initial Methylene Blue concentration and temperature. The adsorption kinetics and isotherms were well fitted by pseudo-second order and Freundlich models, respectively. In addition to that, thermodynamic studies showed an exothermic and a spontaneous process.


2012 ◽  
Vol 616-618 ◽  
pp. 1797-1800
Author(s):  
Yu Mei Gong ◽  
Qing Liang ◽  
Jing Chuan Song ◽  
Ling Ming Xia

This paper presents the preparation of bimodal crystalline macro-/mesoporous titania powders by using a pluronic polymer (EO20PO70EO20, P123) as a template through a hydrothermal treatment. The as-prepared powders were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results reveal that the amount of P123 has a significant effect on the surface area of the mesoporous titania. When the mass ratio of P123:TBOT is 1:14, the crystalline macro-/mesoporous titania has the largest surface area (120.96 m2/g), the average pore diameter of this sample reaches a minimum of 6.67 nm.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Huan-qin Wang ◽  
Ming-bo Zheng ◽  
Jin-hua Chen ◽  
Guang-bin Ji ◽  
Jie-ming Cao

HierarchicalMnO2microfibers were prepared by using cotton as the template andKMnO4as the precursor via an ultrasonic assistance route. The results of scanning electron microscope characterization showed that the concentration ofKMnO4had a significant effect on the morphology ofMnO2microfiber. At low concentration ofKMnO4, the microfiber was composed ofMnO2nanorods with single crystal structure. With increasing the concentration ofKMnO4, the secondary nanostructure ofMnO2microfibers had a transformation from nanorod to nanoparticle. The results ofN2adsorption-desorption analysis indicated thatMnO2microfibers had BET surface area of about 25 m2/g. This synthesis provides a new way to control the secondary nanostructure ofMnO2microfiber by adjusting the concentration of precursor. Furthermore, the mechanism for the replication was proposed and discussed.


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