Hong Liang

Bio: Hong Liang is an academic researcher from Texas A&M University. The author has contributed to research in topics: Chemical-mechanical planarization & Tribology. The author has an hindex of 39, co-authored 297 publications receiving 5981 citations. Previous affiliations of Hong Liang include Stevens Institute of Technology & National Institute of Standards and Technology.

Antibacterial activities of gold and silver nanoparticles against Escherichia coli and bacillus Calmette-Guérin.

Abstract: Background: Diseases such as tuberculosis (TB) have always had a large impact on human health. Bacillus Calmette-Guerin (BCG) is used as a surrogate for TB during the development of anti-TB drugs. Nanoparticles (NPs) have attracted great interest in drug development. The purpose of this study was to examine the potential of NPs as anti-TB compounds by studying the interacting mechanisms between NPs and bacteria. Results: We investigated effects of gold and silver NPs on BCG and Escherichia coli. Experimentally, particle size and shape were characterized using transmission electron microscopy (TEM). Different concentrations of NPs were applied in bacterial culture. The growth of E. coli was monitored through colony forming units (CFU). The mechanism of interaction between NPs and bacteria was analyzed through bacterial thin sections followed by TEM and scanning electron microscopy. Antibacterial effects on BCG were observed by recording fluorescent protein expression levels. Conclusions: The results suggest NPs have potential applications as anti-TB compounds. The antibacterial effects and mechanism of action for NPs were dependent upon composition and surface modifications.

Micro‐ and Nano‐Structured Vanadium Pentoxide (V2O5) for Electrodes of Lithium‐Ion Batteries

Abstract: Vanadium pentoxide (V2O5) has played important roles in lithium-ion batteries due to its unique crystalline structure. To assist researchers understanding the roles this material plays, a comprehensive and critical review is conducted based on about 250 publications. Here, we report basics and applications of micro- and nano-materials of V2O5 and V2O5-based composites. The comparative and statistical analysis leads to the discovery of several interesting phenomena. The V2O5 electrodes with two lithium ions have a favorable capacity performance with reversible phase formation. The excellent capacity retention is displayed in the V2O5 electrodes with one lithium ion inserted. In the case of three lithium ions insertion, it was found that the irreversible formation of the phase ω in LixV2O5 leads to its control. In addition, effects of additives on electrode performance, circuitry models of performance, as well as reaction routes are studied. Two unprecedented concepts of the “high capacity band” and “empirical total capacity retention” are proposed though the comprehensive statistical analysis of the reviewed data. This review provides a comprehensive collection of information of state-of-the-art and recent advancement in V2O5 and V2O5-based composite materials for electrodes. Researchers could use the information to design and develop advanced electrodes for future batteries.

Shape-Controlled Catalysis by Cetyltrimethylammonium Bromide Terminated Gold Nanospheres, Nanorods, and Nanoprisms

Abstract: Shape-controlled Au nanospheres, nanorods, and nanoprisms have been utilized for the first time for selective chemical reduction of different aromatic nitro compounds to the corresponding amino derivatives at room temperature. Careful observation reveals that the reaction was fastest with nanospheres and slowest with nanorods, whereas the rate was intermediate with nanoprisms when keeping the numbers of particles approximately the same. Controlled experiments revealed that our reaction followed the nitroso and hydroxylamine pathway. The yield of the product was very high, and the method should be applicable for very fast catalysis reaction of other nitro compounds.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Abstract: Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Antimicrobial activity of metals: mechanisms, molecular targets and applications

Abstract: Metals have been used as antimicrobial agents since antiquity, but throughout most of history their modes of action have remained unclear. Recent studies indicate that different metals cause discrete and distinct types of injuries to microbial cells as a result of oxidative stress, protein dysfunction or membrane damage. Here, we describe the chemical and toxicological principles that underlie the antimicrobial activity of metals and discuss the preferences of metal atoms for specific microbial targets. Interdisciplinary research is advancing not only our understanding of metal toxicity but also the design of metal-based compounds for use as antimicrobial agents and alternatives to antibiotics.

‘Green’ synthesis of metals and their oxide nanoparticles: applications for environmental remediation

Abstract: In materials science, “green” synthesis has gained extensive attention as a reliable, sustainable, and eco-friendly protocol for synthesizing a wide range of materials/nanomaterials including metal/metal oxides nanomaterials, hybrid materials, and bioinspired materials. As such, green synthesis is regarded as an important tool to reduce the destructive effects associated with the traditional methods of synthesis for nanoparticles commonly utilized in laboratory and industry. In this review, we summarized the fundamental processes and mechanisms of “green” synthesis approaches, especially for metal and metal oxide [e.g., gold (Au), silver (Ag), copper oxide (CuO), and zinc oxide (ZnO)] nanoparticles using natural extracts. Importantly, we explored the role of biological components, essential phytochemicals (e.g., flavonoids, alkaloids, terpenoids, amides, and aldehydes) as reducing agents and solvent systems. The stability/toxicity of nanoparticles and the associated surface engineering techniques for achieving biocompatibility are also discussed. Finally, we covered applications of such synthesized products to environmental remediation in terms of antimicrobial activity, catalytic activity, removal of pollutants dyes, and heavy metal ion sensing.