Physico-Chemical Properties of Silica Coated Superparamagnetic Magnetite Nanoparticles Synthesized by Non-Seeded Process

2015 ◽  
Vol 1107 ◽  
pp. 267-271
Author(s):  
Sodipo Bashiru Kayode ◽  
Azlan Abdul Aziz

The science of core-shell nanoparticles requires investigation into several physical and chemical properties of the composite nanoparticles. Unlike the conventional sol-gel or the reverse microemulsion micelle method, we presented here a non-seeded process of encapsulating superparamagnetic magnetite nanoparticles (SPMN) with silica. Physico-chemical analysis of the product was used to confirm the result of the coating procedure. Colloidal suspension of SPMN and silica nanoparticles were synthesised through coprecipitation method and modified Stöber method respectively. Afterwards, both colloidal suspensions of SPMN and silica nanoparticles were sonicated to encapsulate the SPMN with silica. Elemental mapping of the composite particles with electron spectroscopy imaging (ESI) confirmed the core-shell micrograph of the SPMN and silica. The X-ray diffraction pattern (XRD) showed the silica shell to be in amorphous form. FTIR analysis further confirmed the chemical properties of the product to be silica coated SPMN.

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Ismail Ab Rahman ◽  
Vejayakumaran Padavettan

Application of silica nanoparticles as fillers in the preparation of nanocomposite of polymers has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, and chemical properties. Recent developments in the synthesis of monodispersed, narrow-size distribution of nanoparticles by sol-gel method provide significant boost to development of silica-polymer nanocomposites. This paper is written by emphasizing on the synthesis of silica nanoparticles, characterization on size-dependent properties, and surface modification for the preparation of homogeneous nanocomposites, generally by sol-gel technique. The effect of nanosilica on the properties of various types of silica-polymer composites is also summarized.


2014 ◽  
Vol 896 ◽  
pp. 153-158
Author(s):  
Anis Kristiani ◽  
Kiky C. Sembiring ◽  
Fauzan Aulia ◽  
Joddy Arya Laksmono ◽  
Silvester Tursiloadi ◽  
...  

A series of sulfated zirconia was prepared through sol gel method in alcohol medium. Porosity of the catalyst was developed in two different methods, which were immersion of cetyltrimethyl ammonium chloride (CTAC) surfactant as templating agent and Supercritical Fluid Extraction (SFE). The physico-chemical properties of the catalysts were characterized by Thermal Gravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) and gravimetry method for acidity measurement following by the adsorption of organic bases. The characterization results show that different method of immersing CTAC surfactant and SFE affecting physical and chemical properties, i.e. crystalinity, surface area, pore size, pore volume and acidity.


2016 ◽  
Vol 4 (10) ◽  
pp. 1417-1421 ◽  
Author(s):  
C. Achilli ◽  
S. Grandi ◽  
G. F. Guidetti ◽  
A. Ciana ◽  
C. Tomasi ◽  
...  

Magnetite nanoparticles coated with silica, obtained by a sol–gel process in the reverse micelle microemulsion, were characterized and homogeneously suspended in water in order to assay their biocompatibility toward blood cells, in view of a potential medical use of this material.


2013 ◽  
Vol 2013 ◽  
pp. 1-24 ◽  
Author(s):  
K. Santhosh Kumar ◽  
Vijay Bhooshan Kumar ◽  
Pradip Paik

This paper covers the core-shell nanomaterials, mainly, polymer-core polymer shell, polymer-core metal shell, and polymer-core nonmetal shells. Herein, various synthesis techniques, properties, and applications of these materials have been discussed. The detailed discussion of the properties with experimental parameters has been carried out. The various characterization techniques for the core-shell nanostructure have also been discussed. Their physical and chemical properties have been addressed. The future aspects of such core-shell nanostructures for biomedical and various other applications have been discussed with a special emphasis on their properties.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3492
Author(s):  
Jun Hyup Lee

To achieve the seamless characteristics of displays, liquid crystal (LC) devices need a super-narrow bezel design. This device architecture can be constructed using functional adhesives that possess excellent physical and chemical properties. In this study, mechanically robust ultraviolet (UV)/heat dual-curable adhesives with outstanding reliability and processability have been fabricated using reactive poly(methyl methacrylate) (PMMA)/polyethyleneimine (PEI) core-shell nanoparticles. Their curing characteristics, narrow drawing processability, adhesive strength, elongation at break, and the contact contamination of LCs have been investigated. Compared to conventional adhesive material, the proposed adhesive containing multifunctional PMMA/PEI nanoparticles afforded a high adhesion strength of 40.2 kgf cm−2 and a high elongation of 64.8% due to the formation of a firm crosslinked network with matrix resins comprising bisphenol A epoxy resin and bisphenol A glycerolate dimethacrylate. Moreover, the proposed adhesive showed an excellent narrow drawing width of 1.2 mm, which is a prerequisite for super-narrow bezel display. With regard to LC contamination, it was found that the level of contamination could be remarkably reduced to 61 µm by a high-temperature curing process. This study makes a significant contribution to the development of advanced display, because it provides robust and sustainable display adhesives based on nanomaterials, thereby enhancing the life and sustained operability of displays.


2019 ◽  
Vol 17 (1) ◽  
pp. 1459-1465
Author(s):  
Xuedong Feng ◽  
Jing Yi ◽  
Peng Luo

AbstractWith the purpose of studying the influence of NO/O2 on the NOx storage activity, a Pt-Ba-Ce/γ-Al2O3 catalyst was synthesized by an acid-aided sol-gel method. The physical and chemical properties of the catalyst were characterized by X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results showed that the composition of the catalyst was well-crystallized and the crystalline size of CeO2 (111) was about 5.7 nm. The mechanism of NO and NO2 storage and NOx temperature programmed desorption (NO-TPD) experiments were investigated to evaluate the NOx storage capacity of the catalyst. Pt-Ba-Ce/γ-Al2O3 catalyst presented the supreme NOx storage performance at 350℃, and the maximum value reached to 668.8 μmol / gcat. Compared with O2-free condition, NO oxidation to NO2 by O2 had a beneficial effect on the storage performance of NOx. NO-TPD test results showed that the NOx species stored on the catalyst surface still kept relatively stable even below 350℃.


2020 ◽  
Vol 21 (24) ◽  
pp. 9696
Author(s):  
Miguel Gisbert-Garzarán ◽  
Daniel Lozano ◽  
María Vallet-Regí

Current chemotherapy treatments lack great selectivity towards tumoral cells, which leads to nonspecific drug distribution and subsequent side effects. In this regard, the use of nanoparticles able to encapsulate and release therapeutic agents has attracted growing attention. In this sense, mesoporous silica nanoparticles (MSNs) have been widely employed as drug carriers owing to their exquisite physico-chemical properties. Because MSNs present a surface full of silanol groups, they can be easily functionalized to endow the nanoparticles with many different functionalities, including the introduction of moieties with affinity for the cell membrane or relevant compartments within the cell, thus increasing the efficacy of the treatments. This review manuscript will provide the state-of-the-art on MSNs functionalized for targeting subcellular compartments, focusing on the cytoplasm, the mitochondria, and the nucleus.


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