University of Macau

About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Population & Control theory. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.

A critical review on research progress of graphene/cement based composites

Abstract: Cement based composite materials (CBCM) with superior mechanical strength and excellent durability are always desirable in practical applications. Although considerable research has been reported in the past decades about the use of Nano materials (NMs) for strength and durability enhancement of cement matrix, there is little information available on the use of graphene nano-sheets and their derivatives (GND) in cement-based materials. Particularly the role of GND in hydration processes and their mechanisms of strengthening in cement matrix are unclear. In this paper, a critical review on recent research findings about GND modified cement-based materials was conducted. The review mainly discussed the influence of GND on properties of cement matrix including microstructure, hydration, mechanical properties, etc. The information revealed in this paper would not only provide a comprehensive understanding of the effect of GND on cement composites, but also provide valuable ideas and guidance for similar studies in the future.

Multi-target drugs: the trend of drug research and development.

Abstract: Summarizing the status of drugs in the market and examining the trend of drug research and development is important in drug discovery. In this study, we compared the drug targets and the market sales of the new molecular entities approved by the U.S. Food and Drug Administration from January 2000 to December 2009. Two networks, namely, the target–target and drug–drug networks, have been set up using the network analysis tools. The multi-target drugs have much more potential, as shown by the network visualization and the market trends. We discussed the possible reasons and proposed the rational strategies for drug research and development in the future.

Super-adsorbent hydrogel for removal of methylene blue dye from aqueous solution

Abstract: Adsorptive removal of dyes from industrial effluent has attracted intensive interest in the treatment of water pollution. Although we have witnessed great development in adsorbents for treating dyeing waste water, super-adsorbent hydrogels still cannot meet the high requirement for huge adsorption capacities towards various dyes. Traditional uncross-linked poly(acrylic acid) (PAA) adsorbents possess a low adsorption capacity towards dyes due to the poor three-dimensional structure in the bulk, which has a negative effect on the exposure of adsorptive sites and the penetration of water within the internal channels of the adsorbent. Thus, other monomers or chemical cross-linkers are introduced to design a well-cross-linked PAA-based super-adsorbent hydrogel with the intention of improving its adsorptive behavior. However, the above-mentioned additives may negatively affect the adsorptive properties of composite adsorbents based on the PAA hydrogel. To the best of our knowledge, adsorption capacities of PAA-based super-adsorbent hydrogels for organic dyes reaching more than 2000 mg g−1 have rarely been reported as yet. Therefore, it is urgent to explore super-adsorbent hydrogels with high adsorptive properties to alleviate dye-based water pollution. In this work, a novel poly(acrylic acid) (PAA)-based super-adsorbent nanocomposite hydrogel (NC gel) acting as an effective dye adsorbent is prepared via free radical in situ polymerization of acrylic acid by employing non-aggregated calcium hydroxide (Ca(OH)2) nano-spherulites (CNSs) with a diameter less than 5 nm as cross-linkers. The high water penetration of our super-adsorbent NC gel with a high swelling ratio (500 times) allows the internal adsorption sites to be fully exposed to methylene blue (MB). Thus, the adsorption capacity is as high as 2100 mg g−1 for MB under near neutral pH conditions due to the exposure of a large amount of active sites. This is the first time that it has been reported that a maximum adsorption of more than 2000 mg g−1 for MB has been obtained using a PAA-based super-adsorbent NC gel. In addition, the adsorption behavior of our NC gel matches well with the pseudo-second-order model and Langmuir adsorption isotherm model. This work confirms that CNSs can create a well-cross-linked structure of a PAA hydrogel without the aid of any other cross-linker and further confirms that the PAA-based super-adsorbent NC gel has a potential application in the removal of organic dyes from dyeing waste water.