http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Mohammad Hegazy (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Mohammad Hegazy,Nahla Rahoui,Ahmed Abou- Elyazed,Diaa Eldin Fouad,Xin Huang,Yudong Huang 한국고분자학회 2019 폴리머 Vol.43 No.3
In this paper, pH-responsive nanocarriers based on mesoporous silica nanoparticles (MSN) modified with the pH-sensitive polymer: poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) were constructed, characterized and tested to evaluate their efficacy as drug delivery systems (DDS). The hybrid nanocarriers were synthesized successfully via a simultaneous copolymerization reaction between two monomers; 2-dimethylamino-ethylmethacrylate (DMAEMA) and 3-methacryloxypropyltrimethoxysilane (MPS) within the mesopores of MSN. Exploiting the polymerizable moiety of MPS together with its alkoxysilane moity susceptible to condensation with silanols surface onto silica, MPS comonomer can act as a bridge for yielding a robust and simple hybrid consisting of MSN-P(DMAEMA-co-MPS). In addition, the grafted PDMAEMA serves as efficient gatekeeper to adjust the encapsulation and in vitro release of cargos loaded inside the pores by altering pH values of the medium. These hybrid nanoparticles showed a high loading capacity with quick release in acidic pH, which exists mainly in the diseases environments e.g. inflammatory and cancerous sites.
-
Abdelkareem, Mohammad Ali,Sayed, Enas Taha,Mohamed, Hend Omar,Obaid, M.,Rezk, Hegazy,Chae, Kyu-Jung Elsevier 2020 Progress in energy and combustion science Vol.77 No.-
<P><B>Abstract</B></P> <P>Fuel cells are electrochemical devices that convert chemical energy directly into electrical energy with high efficiency. The high cost of platinum catalysts and sluggish reaction kinetics are the main challenges in the development of low-temperature fuel cells. Although significant efforts have been made to prepare effective non-precious-metal-based oxygen reduction reaction (ORR) catalysts, suitable anodic catalysts are still far from realization. The reported onset potential of a nonprecious anodic catalyst toward low-molecular-weight hydrocarbons, such as methanol, ethanol, and urea, in alkaline media is approximately 0.35 V (vs. Ag/AgCl), which is far from the theoretical potentials of −0.61, −0.54, and −0.55 V (vs. Ag/AgCl), respectively. Therefore, some researchers concluded that nonprecious anodic catalysts are not practical, taking into account the ORR potential of 0.2 V (vs. Ag/AgCl) in alkaline media. Recently, however, several reports demonstrated an open-circuit voltage (OCV) of more than 0.8 V using non-precious-metal-based anodic catalysts, which contradicts expectations. Therefore, to answer these conflicting claims, this review intensively discusses the possibility of using nonprecious metals, for example Ni-based catalysts, for actual electricity generation in direct (methanol, ethanol, and urea) fuel cells, and the different methods applied to achieve the highest values of OCV. Also, the progress done in the preparation of nonprecious anodic catalysts is reviewed. Finally, conclusions and recommendations to prepare durable and active fuel cells using non-precious-metal-based anodic catalysts are presented.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
