Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Nanosci Nanotechnol ; 15(10): 7935-41, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26726443

RESUMO

Flavonoids have recently attracted significant interest as potential reducing agents, hydrogen-donating antioxidants, and singlet oxygen-quenchers. Quercetin, in particular, induces the expression of a gene, known to be associated with cell protection, in dose- and time-dependent manners. Therefore, quercetin may be used as an effective cosmeceutical material useful in the protection of dermal skin. In this study, hollow porous silica spheres used to load quercetin were prepared by using a combined emulsion sol-gel process and triblock copolymer as a template. Fabrication of hollow porous silica spheres was performed under various conditions such as the molar ratios of H2O/TEOS (Rw) and weight ratios of poloxamer 184/poloxamer 407. Loading of quercetin in hollow porous silica spheres was devised to improve the stability of quercetin and to consider the possibility as a raw cosmetic material. The surface of inclusion complexes of quercetin in hollow porous silicas was modified to enhance the stability of quercetin. The physicochemical properties of the samples were investigated using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA)-differential thermal analysis (DTA) and Brunauer-Emmett-Teller (BET) surface area and porosity analysis. Determination of quercetin concentration was carried out by high-performance liquid chromatography (HPLC) analysis.


Assuntos
Antioxidantes/química , Quercetina/química , Dióxido de Silício/química , Oxigênio Singlete/química , Emulsões , Oxirredução , Transição de Fase , Porosidade
2.
J Nanosci Nanotechnol ; 14(11): 8777-82, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25958602

RESUMO

Shape control of inorganic nanomaterials during hydrothermal syntheses is crucial for fine-tuning the function of these materials, which are widely utilized in semiconductors, ceramics, and optical devices. In particular, magnesium compounds possess many desirable physical properties such as high thermal stability, wide band gap and high secondary electron emission yield, which allow their application as polymeric resins, cements, reinforcements, and fillers. However, conventional synthetic methods often require extreme reaction conditions such as high temperatures, high pressures, or prolonged reaction times. Additionally, various shape control methods are typically quite complicated and time consuming under conventional parameters. In this work, magnesium oxysulfate (5Mg(OH)2 x MgSO4 x 3H2O) granules of various shapes were fabricated by introducing ethanolamine chelate during hydrothermal reaction at a relatively low temperature and pressure. The strong interaction between ethanolamine and Mg2+ produced 5Mg(OH)2 x MgSO4 x 3H2O granules in the form of flakes, flowers, or whiskers through self-assembly this formation is dependent on concentration, reaction time, and temperature. The physicochemical properties of the samples were investigated using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...