Becoming a zero single use plastic nation

WHAT once seemed impossible to start has begun, what was once a habit that seemed impossible to change has started to turn around. And it all started when Yeo Bee Yin announced her "break-up" with single-use plastic in September 2018. As a researcher working in biodegradable materials, I know that the Energy, Science, Technology, Environment and Climate Change Minister's initiative could lead to a greener Malaysia. Greener Malaysia does not only mean more trees in the country but also less harm and pollution caused by the non-degradable single-use plastic materials. There will be less single-use plastics consumed, thus leading to a greener place to live in. Single-use plastics are highly sought after for their durability, cheapness and convenience. We basically do not need to think of clean-up when drinking from a plastic bottle or when buying curry puffs in plastic bags and throwing the bags away without thinking. We must realise that what is convenient for us is actually harmful to the environment. We do not want future generations to deal with the waste that we are producing now due to our negligence. I was very thrilled to see one state after another taking up the plastic straw ban, as reported in The Star on Feb 16 ("For the sake of environment"; online at bit.ly/star_ plastic). Could we become a zero single-use plastic nation one day? There should also be sustainable and environmentally friendly materials to replace plastic straws and bags. There must be a replacement for a ban. This is the time for local innovators to bring forward their inventions

The future of energy harvesting: a brief review of MXenes-based triboelectric nanogenerators

Triboelectric nanogenerators (TENGs) have shown immense potential as self-powering devices for energy harvesting, electronics, and self-powered sensing devices. However, the performance of TENGs largely depends on the materials used, therefore, it is crucial to select appropriate materials. While dielectric polymers, metals, and inorganic materials have been commonly employed as active materials for TENGs, there is a need to explore new materials that offer improved performance. One promising material is two-dimensional MXenes, which have shown exciting potential in various applications, including wearable sensors and electrochemical energy storage. For this reason, further research is needed to fully evaluate the performance of MXenes-based TENGs and to determine their suitability for practical applications. This review emphasizes the significance of material selection in order to optimize the performance of triboelectric nanogenerators (TENGs). Here, the mechanism of TENGs is clearly explained for devices that convert mechanical energy into electric energy. The concept of the triboelectric effect is also described, which generates charge density on material surfaces, along with various types of TENG working modes. The selection of materials is thoroughly discussed, highlighting the growing interest in polymeric and biopolymeric materials, as well as functionalized and inorganic triboelectric materials. Also, exploration of materials that can enhance the output of TENGs, such as chemical modification techniques and the utilization of 2D materials like graphene and MXenes to improve triboelectricity is also included. The synthesis methods and techniques for MXenes are explored in detail. Furthermore, the performance of MXenes-based TENGs for energy harvesting and self-powered sensing is evaluated, and their potential applications in wearable devices are assessed. The study concludes by providing recommendations for future research on MXenes-based TENGs and their applications in wearable devices

Preparation and characterization of polylactic acid based polyurethane for environmental friendly packaging materials

Conventional packaging materials are mostly produced using petroleum-based substances and its’ non-biodegradability are causing landfill problems. Therefore, researches have been done to replace the non-degradable polymer substances to degradable polymers. Polylactic acid (PLA) is a type of biodegradable polymer which is brittle but has good mechanical strength, which makes it a suitable polymer to be used as packaging materials. To improve the flexibility of PLA, PLA based polyurethanes (PUs) are produced by using PLA-diol with vegetable oil polyol as the chain extender. Palm oil polyol (PO) is a type of vegetable oil polyol which are used in various productions of PUs. In this study, PO polyol is used as soft segment to improve the flexibility of PLA whereas hexamethylene diisocyanate (HDI) and toluene diisocyanate (TDI) are used as a source of isocyanate. PLA/Palm oil polyol based polyurethanes (PLAPOPUs) are synthesized using one-shot and two steps polymerization method. Fourier Transform Infra-Red (FT-IR) spectra confirmed on the formation of urethane bond and glass transition temperature was analyzed using Differential Scanning Calorimetry (DSC). The PLAPOPU prepared using HDI through one-step method has high potential to be used in environmental friendly packaging industries

Role of electrocoagulation in wastewater treatment: a developmental review

Electrocoagulation (EC) is a popular wastewater treatment alternative that had been studied extensively for a wide range of wastewater types, due to its versatility, ease of setup, low footprint and eco-friendly nature. The recent studies on EC advancements on various wastewater types had been reviewed in this paper. The operational variables that are vital to EC and the fundamental relationship of EC with conventional chemical coagulation had been assessed as they are the primary factors that govern the pollutant removal mechanism of the process. Hence, EC needs further studies for optimisation of its process parameters and modelling for scale up in the industrial level. Moreover, this paper reviews the current emerging hybrid technologies of EC with integrated separation technologies and their limitations for enhanced wastewater treatment systems for cleaner effluents, water reclamation and recycle. The current prominent hybrid EC processes under research include: EC-adsorption, EC-peroxidation, EC-chemical coagulation (CC), photovoltaic EC and EC-membrane. Due to the overall low footprint requirement, environmental sustainability and strong potential of constant operation without needing extensive control, hybrid EC-membrane process undeniably stands out to be the future of wastewater treatment

Effectiveness of pre-procedural rinsing with essential oils-based mouthrinse to reduce aerosol contamination of periodontitis patients

This research aims to evaluate the effectiveness of pre-procedural rinsing using essential oils-mouthwash (Listerine®) in reducing bioaerosol contamination in a dental clinic. Thirty (30) subjects who consisted of those receiving treatment for periodontitis problems were randomly assigned to rinse with either 20 mL of Listerine® or 20 mL of placebo as control rinse. Every subject was instructed to gargle using the rinse for 1 min. Microbial samples of environmental air and saliva were collected before and after the rinse. All samples were further analyzed for total plate counts to measure the microbial level. Rinsing using Listerine® showed significant reduction in the level of microbial load in saliva compared to the control mouthrinses. Analysis done at three defined distance intervals from the operating site showed the level of bioaerosol contamination was highest at distance nearest to the treatment point of 1 ft. Based on counts of cfu, there was higher presence of microbial contaminant in bioaerosols of the control-rinsed group compared to the test-rinsed group using Listerine®. Therefore, it can be concluded that rinsing using Listerine® was effective towards reducing the microorganisms in saliva and oral cavity in general

Properties of sulphur in colloidal system: a review

Sulfur has been highly sought by many industries everywhere around the world for various applications. This exceptionally useful element has been largely manufactured especially in powder form each year reflecting its increase in demand in line with technological advancement and uses for various product applications. The manufacturing processes include mining as well as chemical reactions in Claus Process. Rubber industries normally use abundance of sulfur in their latex compound to introduce vulcanization. The geneal concern of sulfur for rubber vulcanization is dispersibility in the rubber matrix due to improper optimization of its preparation process prior to latex compounding. Another crucial issue is crystallization of soluble sulfur from its insoluble origin, either during or post-rubber vulcanization that constitutes to formation of sulfur bloom that grows on the surface of the rubber articles. It is known that both issues are related to the process conditions and compounding recipe that could not be fully solved. Various studies have been conducted to minimize such occurences – from process optimization to sulfur chemistry itself – and of continuous improvement and innovation to solve various threats in sulfur applications. This paper reviews on detailed description on elemental sulfur, of respective industrial applications, and most importantly highlights on sulfur trends and issues normally encountered

Properties of polylactic acid biocomposite foamed treated via supercritical carbon dioxide

In this study, polylactic acid (PLA) was incorporated with durian skin nanofibre (DSNF) and cinnamon essential oil (CEO), where the DSNF was extracted through freeze drying process. Supercritical carbon dioxide (SCCO2) acts as physical foaming agent for PLA biocomposite. The tensile strength and chemical interaction between PLA, DSNF, and CEO were investigated. The tensile strength of PLA biocomposite foamed reduced in presence of DSNF, however when only CEO incorporated in PLA the tensile increase and through FTIR graph functional group of PLA biocomposite foamed were identified. The foam structure produced after PLA biocomposite treated via SCCO2 was not fully nucleated and unstable as shown through SEM. The addition of DSNF and CEO did affect the PLA biocomposite foam

ELECTROCHEMICAL CHARACTERIZATION OF POLYLACTIC ACID-BLOCK-POLY(2-VINYLPYRIDINE)/GOLD NANOPARTICLE COMPOSITES FOR GLUCOSE BIOSENSOR DEVELOPMENT

Nanocomposites that consist of diblock copolymer (BCP) and gold nanoparticles (AuNPs) can be applied as a matrix to immobilize enzymes or other molecules based on the well-defined core/shell nanostructures of these composites. In this research, polylactic acid-block-poly(2-vinylpyridine) (PLA-b-P2VP)/hydrogen tetrachloroaurate(III) hydrate (HAuCl4.3H2O) composites were hybridized and then reduced in dichloromethane (DCM) solution. The hybridizations between gold precursors and the P2VP domain were prepared with different ratios of gold to P2VP block (1:1, 1:5, 1:10, 5:1, 10:1) by taking advantage of the association between the long-pair nitrogen of the pyridine group of P2VP. The reduction of the Au3+/PLA-b-P2VP composite was accomplished by hydrazine solution in order to get gold nanoparticle/PLA-b-P2VP composites, which was visually confirmed by a direct color change from bright yellow to purple. In this work, ultraviolet–visible (UV-vis) spectroscopy and Fourier transform infrared spectroscopy (FTIR) were used to confirm the association between gold precursors and pyridine groups as well as the synthesis of gold nanoparticles.The composite which labeled as R3 (Au3+: P2VP = 10:1) showed the highest peak current based on the cyclic voltammetry (CV) measurment. Furthermore, graphene oxide (GO) was added into R3 to prepare BCP/AuNPs/GO composite and reduced to BCP/AuNPs/rGO through electrochemical reduction. The resulting BCP/AuNPs/rGO showed high potential to be used in amperometric biosensor

Recent applications of molecularly imprinted polymers (MIPs) on screen-printed electrodes for pesticide detection

The overuse of pesticides in agricultural sectors exposes people to food contamination. Pesticides are toxic to humans and can have both acute and chronic health effects. To protect food consumers from the adverse effects of pesticides, a rapid monitoring system of the residues is in dire need. Molecularly imprinted polymer (MIP) on a screen-printed electrode (SPE) is a leading and promising electrochemical sensing approach for the detection of several residues including pesticides. Despite the huge development in analytical instrumentation developed for contaminant detection in recent years such as HPLC and GC/MS, these conventional techniques are time-consuming and labor-intensive. Additionally, the imprinted SPE detection system offers a simple portable setup where all electrodes are integrated into a single strip, and a more affordable approach compared to MIP attached to traditional rod electrodes. Recently, numerous reviews have been published on the production and sensing applications of MIPs however, the research field lacks reviews on the use of MIPs on electrochemical sensors utilizing the SPE technology. This paper presents a distinguished overview of the MIP technique used on bare and modified SPEs for the detection of pesticides from four recent publications which are malathion, chlorpyrifos, paraoxon and cyhexatin. Different molecular imprint routes were used to prepare these biomimetic sensors including solution polymerization, thermal polymerization, and electropolymerization. The unique characteristics of each MIP-modified SPE are discussed and the comparison among the findings of the papers is critically reviewed

Potential food additive of Boswellia carterii essential oil encapsulated within gum Arabic: a particle size distribution and zeta potential analysis

Boswellia carterii (BC) {Burseraceae family} essential oil (EO) were extracted by hydrodistillation process. Gum Arabic (GA) {Acacia senegal} polymer particles containing a BCEO were prepared by spray drying technique. The mean particle size and its distribution, as well as the zeta-potential of the microcapsules, were analyzed and found Z-Average 382±203nm, PDI 0.77±0.3, ZP-25±2.73mV, respectively. Product encapsulation efficiency (EE %) was found at 75±0.8%. The surface morphology of the particles was obtained by scanning electron microscope (SEM). Furthermore, particles moisture content was analyzed by the oven drying method. The efficiency of encapsulation (EE %) was estimated by specifying the content of essential oil in the product. Gas chromatography (GC) coupled with time-of-flight mass spectrometry (TOFMS) analysis of EO has been performed to determine the chemical compounds and their prevalence concentrations respectively. The composition of initial essential oil (added in the emulsion) and the encapsulated essential oil (extracted from spray dried powder) were analyzed and compared. The outcome of the research encourages the high potentiality and usefulness of the product in the food industries sector as a food additive agent, moreover, it suggests for further research to unravel potential implementation of BCEO microcapsules in the food production chai