A biomimetic approach to enhancing interfacial interactions: polydopamine-coated clay as reinforcement for epoxy resin

A facile biomimetic method was developed to enhance the interfacial interaction in polymer-layered silicate nanocomposites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was constructed on clay surface by a controllable coating method. The modified clay (D-clay) was incorporated into an epoxy resin, it is found that the strong interfacial interactions brought by the polydopamine benefits not only the dispersion of the D-clay in the epoxy but also the effective interfacial stress transfer, leading to greatly improved thermomechanical properties at very low inorganic loadings. Rheological and infrared spectroscopic studies show that the interfacial interactions between the D-clay and epoxy are dominated by the hydrogen bonds between the catechol-enriched polydopamine and the epoxy.     

Engineered Microvessel for Cell Culture in Simulated Microgravity

As the number of manned space flights increase, studies on the effects of microgravity on the human body are becoming more important. Due to the high expense and complexity of sending samples into space, simulated microgravity platforms have become a popular way to study these effects on earth. In addition, simulated microgravity has recently drawn the attention of regenerative medicine by increasing cell differentiation capability. These platforms come with many advantages as well as limitations. A main limitation for usage of these platforms is the lack of high-throughput capability due to the use of large cell culture vessels. Therefore, there is a requirement for microvessels for microgravity platforms that limit waste and increase throughput. In this work, a microvessel for commercial cell culture plates was designed. Four 3D printable (polycarbonate (PC), polylactic acid (PLA) and resin) and castable (polydimethylsiloxane (PDMS)) materials were assessed for biocompatibility with adherent and suspension cell types. PDMS was found to be the most suitable material for microvessel fabrication, long-term cell viability and proliferation. It also allows for efficient gas exchange, has no effect on cell culture media pH and does not induce hypoxic conditions. Overall, the designed microvessel can be used on simulated microgravity platforms as a method for long-term high-throughput biomedical studies.     

Innovative lane detection method to increase the accuracy of lane departure warning system

Multimedia Tools and Applications - Lane departure warning is one important feature in Advanced Driver Assistance Systems (ADAS), which aims to improve overall safety on the road. However,...     

Phosphonated graphene oxide with high electrocatalytic performance for vanadium redox flow battery

Development of more efficient electrodes is essential to improve the competitiveness of vanadium redox flow battery (VRFB) systems. Covalent functionalization of carbon structure in graphene oxide with phosphonic acid groups was carried out to enhance the electrode wettability. The phosphonated graphene oxide (P-GO) was characterized and found displaying an improved electrocatalytic performance towards electrooxidation/electroreduction of vanadium ion pairs. The defect in P-GO structure increased the negative charge density on the surface leading to higher vanadium ions tendency for electrooxidation/electroreduction reactions. The battery performance was evaluated using electrodes made of carbon felt hosted GO and P-GO in a single cell VRFB and 180 charge-discharge cycles were recorded. The VRFB with P-GO displayed an improved performance and stable coulombic, voltage and energy efficiency compared to VRFB with GO.     

Hypochlorite oxidation of cyanate under mildly alkaline conditions

Kinetic study was carried out on the hypochlorite oxidation of cyanate, over the pH range of 8.6–10.0 and temperature range from 27 to 50°C. The decomposition reaction was found to be first order each with respect to cyanate, hypochlorite and hydrogen ion concentration. The experimental results indicate that the decomposition reaction may probably follow a series reaction in which the cyanate first hydrolyses to ammonium which then decomposes in alkaline hypochlorite solution to nitrogen. Under the range of pH and hypochlorite/cyanate molar ratio examined in this study, the stoichiometric ratio of hypochlorite to cyanate for the decomposition reaction is found to be approx. 1.5. The conversion of cyanate to nitrate is negligible compared with that to nitrogen. This study suggests that complete treatment of cyanide waste is best carried out in two stages at room temperature and in the presence of excess hypochlorite. The first stage involves the hypochlorite oxidation of cyanide to cyanate at pH 11 and the second stage involves the conversion of the cyanate to nitrogen and other stable inert products at a reduced pH of about 9.     

Building adaption model in assessing adaption potential of public housing in Singapore

Building adaptation is instrumental in curbing building degradation and urban dilapidation. Owing to budget constraint, the policy decision makers who manage substantial public buildings always face the problems of which existing buildings should be selected for adaptation. A tool is required to aid them to prioritise existing buildings based on their adaptation potential. Thus, the aim of this study is to develop a model which acts as a tool for the policy decision makers to perform the challenging work of prioritising the existing public housing for adaption. This research presents a conceptual framework for assessing adaptation potential of existing public housing in Singapore and discusses its validation process. The results show that the proposed approach is effective in estimating the adaptation potential of existing residential buildings. In practice, the decision makers can use this model to rank existing buildings’ adaptation potential and select those buildings with high potential for adaptation, with the intention to optimise the allocation of a tight building adaptation budget.     

A Pulsed NMR Method for the Study of Starch Retrogradation

A rapid and non-destructive pulsed NMR method of monitoring starch retrogradation was developed based on the principle that the signals from protons in the “solid-like” and liquid components in a system decay at significantly different rates following a 90° radio-frequency pulse. As molecular association or recrystallization proceeds during aging of a starch gel, the proportion of the “solid-like” component in the system increases. The resulting decrease in segmental mobility of the starch chains causes a decrease in the signal from the liquid component, but a concomitant increase in the signal attributed to protons in the “solid-like” fraction. The method was applied to study the retrogradation tendency of starches from different botanical sources.