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In this work, the use of carboxymethyl cellulose (CMC) is highlighted in enhancing the controlled release behaviour of zinc/aluminium layered double hydroxide-quinclorac (Zn/Al-LDH-QC). The Zn/Al-LDH-QC-CMC nanocomposite were characterised using powder x-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric and derivative thermogravimetric analysis and field emission scanning electron microscopy. The release study was carried out in an aqueous solution of Na3PO4, Na2SO4 and NaCl, so as to mimic the environmental condition where the QC is frequently used. The Zn/Al-LDH-QC-CMC nanocomposites showed better performance in releasing QC, with prolonged release time ranging from 163–6083 min, compared to 99–2639 min for the uncoated nanocomposites. The hygroscopic nature of the CMC play a critical role in enhancing the release behaviour of the Zn/Al-LDH-QC-CMC. The kinetic study shows that the Zn/Al-LDH-QC-CMC follows the pseudo-second order kinetic model; hence the release mechanism occurred via dissolution of the CMC matrix and the ion exchange process. These results, therefore, indicate the potential of Zn/Al-LDH-QC-CMC in dealing with the downside effect of the excessive usage of herbicide in paddy cultivation.

The aim of this study is to modulate the controlled release properties of zinc hydroxide nitrate–sodium dodecylsulphate–bispyribac (ZHN–SDS–BP) nanocomposite, by coating the nanocomposite using chitosan. This study was conducted as part of an effort to reduce the environmental problems caused by the over-use of pesticides. The characterisation study shows that chitosan had been successfully coated onto the outer surface of the ZHN–SDS–BP (BP concentration of 0.05 M) without changing the types of ions intercalated in its interlayer gallery. The chitosan-coated nanocomposite, ZHN–SDS–BP–Chi also possesses a better thermal stability compared to the uncoated nanocomposite. Owing to the polycationic, hygroscopic nature, and gelation ability of chitosan, the chitosan coating was found to significantly prolong the release of bispyribac. The ZHN–SDS–BP–Chi showed a better performance in releasing pesticides, with prolonged release time ranging from 462 to 5349 min, compared to 74 to 4117 min for the uncoated nanocomposites. The release kinetic studies reveal that the release of bispyribac from the ZHN–SDS–BP–Chi is controlled by a pseudo-second-order kinetic model, thus signifying that the release mechanism is via dissolution and ion-exchange processes. The potential of chitosan in slowing the release of BP from ZHN–SDS–BP–Chi will hopefully contribute to minimise the risk of pollution resulting from the excessive use of pesticides.

The negative effects of dye-contaminated wastewater on humans and the environment are well known, so the wastewater must be treated carefully before discharge into the environment. To overcome those impacts, the search for environmentally friendly and low-cost materials is essential, especially in developing countries The objective of the present study was to determine the feasibility of using bauxite from Malaysia as a new and efficient ceramic, hollow-fiber membrane for the degradation of reactive dyes in wastewater. A porous, hollow-fiber membrane was fabricated from bauxite (BHFM) using a phase-inversion technique, followed by sintering at various temperatures. The BHFM consisted of two types of voids, having either a finger-like or a sponge-like structure. As the sintering temperature was increased, the porosity of the BHFM decreased from 46.5 to 9.5%. The greatest mechanical strength of 308.1 MPa was achieved when the BHFM was loaded with 55 wt.% of bauxite and sintered at 1450°C. The remaining 45 wt.% consisted of solvent, polymer binder, and dispersant. The BHFM functioned well as a membrane for microfiltration and a support membrane for ultrafiltration. BHFM with loading of 45 wt.%, 50 wt.%, and 55 wt.% successfully eliminated 90%, 94%, and 98% of 10 ppm reactive dye (RB5) when sintered at the highest temperature.

A new nano host-fungicide, namely zinc hydroxide nitrate–sodium dodecyl sulphate–fluazinam (ZHN–SDS–FZ) was successfully synthesised using an ion exchange method. The intercalation of fluazinam (FZ) in the interlayer gallery of ZHN–SDS was confirmed by PXRD pattern with the basal spacing of 32.7 A. The FTIR confirmed that FZ exist in the interlayer gallery. The elemental analysis also supported the presence of FZ in the interlayer ZHN–SDS where the percentages of nitrogen, which contributed by FZ was 65.6%. Meanwhile, the percentages of Zn in the nano host-fungicides was estimated to be 11.5%. Furthermore, TGA/DTG pattern showed that the nano host-fungicide ZHN–SDS–FZ has better thermal stability compared to pure FZ. The intercalation of FZ leads to the change of morphology, surface area and also the porosity. The classification of porosity of ZHN–SDS is mesoporous, meanwhile ZHN–SDS–FZ is non-porous. The BET-BJH surface area shows that ZHN–SDS and ZHN–SDS–FZ is of Type IV and Type III respectively. The controlled release of FZ from the ZHN–SDS–FZ nano host showed that phosphate and carbonate solutions yield the higher percentages of release compared to chloride solutions. The controlled release of FZ was found to be governed by a pseudo-second order mechanism for all medium. In this research, FZ can act as a good guest anion to be intercalated in the interlayer ZHN–SDS to be further used in agricultural sector due to the slowest release of FZ in the phosphate, carbonate and chloride solutions as a release medium.

Solid oxide fuel cell (SOFC) is an attractive device that can convert chemical into energy. Recently, the triple layer hollow fiber (TLHF) opens up a new discovery of higher power output. This study investigates the fabrication of TLHF in solid oxide fuel cell consisting anode/anode functional layer (AFL)/electrolyte (NiO-YSZ/NiO-YSZ/YSZ) via single-step phase inversion-based co-extrusion combined with co-sintering technique using methane as fuel. TLHF formed sandwich-like structure that corresponds to the anode and AFL with dense electrolyte. Initially, the open circuit voltage (OCV) was 1.1 V, after 90 min, the OCV dropped to 0.2 V due to the carbon deposits that caused poisoning. Meanwhile, the power density also reduces from 0.8 to 0.33 Wcm−2. SEM image carbon shows the carbon deposited causing crack and reached electrolyte layer. TEM of the Ni catalyst indicates there are multilayer of graphite exhibit at the Ni particle courtesy of the carbon deposits. The results showed the graphite causing the performance to decrease which is corresponding to the usage of methane as fuel.

Bispyribac (BP) anions have been successfully intercalated in the interlayer region of zinc hydroxide nitrate (ZHN) in the presence of sodium dodecylsulphate (SDS) surfactant. The physicochemical properties of the intercalation compound ZHN–SDS–BP have been characterised herein with different instrumental techniques. The intercalation of BP and SDS is clearly reflected in the PXRD analysis, based on the appearance of symmetrical, sharp and intense intercalation peaks at lower 2θ with a basal spacing of 28.2–28.6 Å. The thermal studies show that the ZHN–SDS–BP nanocomposite has better thermal stability than the pristine BP. The intercalation of BP leads to significant changes in the surface area, porosity, and morphology. Nitrogen adsorption–desorption isotherms reveal that both ZHN–SDS and ZHN–SDS–BP are of Type IV. The release and kinetic studies were also carried out on the ZHN–SDS–BP, in aqueous solution of Na3PO4, Na2SO4 and NaCl as the release media. The releases of BP in both aqueous solutions of Na3PO4 and NaCl were found to follow the pseudo second order kinetic model, whereas the releases of BP in the aqueous solution of Na2SO4 obey the parabolic diffusion kinetic model. This study shows that ZHN has the potential to be used as a host material in slowing the release of BP herbicides in the paddy cultivation sector. Keywords: Nanocomposite, Bispyribac, Zinc hydroxide nitrate, Sodium dodecylsulphate, Intercalation

Carboxymethylcellulose (CMC) acts as a coating material for a magnesium-layered hydroxide-3-(4-methoxyphenyl)propionate (MLH-MPP) nanocomposite via spontaneous self-assembly. The resulting product is called a magnesium-layered hydroxide-3-(4-methoxyphenyl)propionate/carboxymethylcellulose (MLH-MPP/CMC) nanocomposite. The XRD pattern of the MLH-MPP/CMC nanocomposite showed that MPP was maintained in the interlayers of the MLH, thus confirming that CMC is only deposited on the surface of the MLH-MPP nanocomposite. These findings were also supported by FTIR spectra, SEM and TEM. TGA data showed that the thermal stability of the intercalated MPP was significantly enhanced compared to pure MPP and uncoated nanocomposite. The release of MPP from the interlayers of MLH-MPP/CMC nanocomposite showed slower release than did uncoated nanocomposite and followed pseudo–second-order kinetics. Since the herbicide, MPP was released from the synthesised nanocomposite in a sustained manner, thus, it has excellent potential to be used as a controlled-release herbicide formulation. Keywords: Magnesium-layered hydroxide, 3-(4-Methoxyphenyl)propionic acid, Carboxymethylcellulose, Direct reaction method, Controlled release

A neutrally charged insecticide, imidacloprid (IC), has been intercalated into zinc hydroxide nitrate (ZHN) with the assistance of sodium dodecylsulphate (SDS). The presence of SDS assists the intercalation of IC by forming a hydrophobic region in the interlayer gallery of ZHN. The intercalated compound, ZHN–SDS–IC, was characterised using powder X-ray diffraction (PXRD), thermogravimetric analysis, Fourier transform infrared spectroscopy, elemental analysis, field emission scanning electron microscopy, and gas sorption analysis. The PXRD studies demonstrated intercalation peaks at lower 2θ, which confirmed the intercalation of IC and SDS in the interlayer gallery of ZHN. The release and kinetic studies of ZHN–SDS–IC reveals that the IC were successfully released in controlled manner (with release time up to 1478 min), and were governed by pseudo second order kinetic model. The ZHN–SDS–IC synthesised is hopefully beneficial in overcoming the consequences of excessive usage of insecticide in paddy cultivation.

Sodium dodecyl sulphate surfactant was intercalated into the layered zinc hydroxide salt for the successful adsolubilisation of poor water-soluble pesticide, thiacloprid. The intercalation ...

The generation of surfactant-assisted exfoliated graphene oxide (sEGO) by electrochemical exfoliation is influenced by the presence of surfactants, and in particular the hydrophobic tail molecular-architecture. Increasing surfactant chain branching may improve the affinity for the graphite surfaces to provide enhanced intersheet separation and stabilisation of exfoliated sheets. The resulting sEGO composites can be readily used to remove of a model pollutant, the dye, methylene blue (MB), from aqueous solutions by providing abundant sites for dye adsorption. This article explores relationships between surfactant structure and the performance of sEGO for MB adsorption. Double-branched and highly branched triple-chain graphene-compatible surfactants were successfully synthesised and characterised by1H NMR spectroscopy. These surfactants were used to produce sEGOviaelectrochemical exfoliation of graphite, and the sEGOs generated were further utilised in batch adsorption studies of MB from aqueous solutions. The properties of these synthesised surfactants were compared with those of a common single-chain standard surfactant, sodium dodecyl-sulfate (SDS). The structural morphology of sEGO was assessed using Raman spectroscopy and field emission scanning electron microscopy (FESEM). To reveal the links between the hydrophobic chain structure and the sEGO adsorption capacity, UV-visible spectroscopy, zeta potential, and air-water (a/w) surface tension measurements were conducted. The aggregation behaviour of the surfactants was studied using small-angle neutron scattering (SANS). The highly branched triple-chain surfactant sodium 1,4-bis(neopentyloxy)-3-(neopentylcarbonyl)-1,4-dioxobutane-2-sulfonate (TC14) displayed enhanced exfoliating efficiency compared to those of the single-and double-chain surfactants, leading to ∼83% MB removal. The findings suggest that highly branched triple-chain surfactants are able to offer more adsorption sites, by expanding the sEGO interlayer gap for MB adsorption, compared to standard single-chain surfactants.

A facile electrochemical exfoliation method was established to efficiently prepare conductive paper containing reduced graphene oxide (RGO) with the help of single chain anionic surfactant ionic liquids (SAILs). The surfactant ionic liquids are synthesized from conventional organic surfactant anions and a 1-butyl-3-methyl-imidazolium cation. For the first time the combination of SAILs and cellulose was used to directly exfoliate graphite. The ionic liquid 1-butyl-3-methyl-imidazolium dodecylbenzenesulfonate (BMIM-DBS) was shown to have notable affinity for graphene, demonstrating improved electrical properties of the conductive cellulose paper. The presence of BMIM-DBS in the system promotes five orders of magnitude enhancement of the paper electrical conductivity (2.71 × 10−5 S cm−1) compared to the native cellulose (1.97 × 10−10 S cm−1). A thorough investigation using electron microscopy and Raman spectroscopy highlights the presence of uniform graphene incorporated inside the matrices. Studies into aqueous aggregation behavior using small-angle neutron scattering (SANS) point to the ability of this compound to act as a bridge between graphene and cellulose, and is responsible for the enhanced exfoliation level and stabilization of the resulting dispersion. The simple and feasible process for producing conductive paper described here is attractive for the possibility of scaling-up this technique for mass production of conductive composites containing graphene or other layered materials.

Hydrothermal method has been proven to be an effective method to synthesise the nanostructured titanium dioxide (TiO2) with good morphology and uniform distribution at low temperature. Despite of employing a well-known and commonly used glass substrate as the support to hydrothermally synthesise the nanostructured TiO2, this study emphasised on the application of kaolin hollow fibre membrane as the support for the fabrication of kaolin/TiO2 nanorods (TNR) membrane. By varying the hydrothermal reaction times (2 h, 6 h, and 10 h), the different morphology, distribution, and properties of TiO2 nanorods on kaolin support were observed by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). It was found that the well-dispersed of TiO2 nanorods have improved the surface affinity of kaolin/TNR membrane towards water, allowing kaolin/TNR membrane prepared from 10 h of hydrothermal reaction to exhibit the highest water permeation of 165 L/h.m2.bar. In addition, this prepared membrane also showed the highest photocatalytic activity of 80.3% in the decolourisation of reactive black 5 (RB5) under UV irradiation. On top of that, the kaolin/TNR membrane prepared from 10 h of hydrothermal reaction also exhibited a good resistance towards photocorrosion, enabling the reuse of this membrane for three consecutive cycles of photocatalytic degradation of RB5 without showing significant reduction in photocatalytic efficiency towards the decolourisation of RB5.

In this study, we report a novel and efficient way to produce large-area graphene and syngas simultaneously from CH4 and CO2 via CVD. The successful synthesis of syngas was confirmed by online gas chromatography characterization whereas the graphene produced within the same process was verified using Raman spectroscopy, Raman mapping and HRTEM. This work helps to better understand graphene growth from CH4 and CO2 and improve the CVD method by providing a novel pathway for the synthesis of large-area graphene with a valued by-product. With our derived CVD approach, graphene was grown while producing syngas and consuming green-house gases which is of great importance in this current climate change phenomenon.

Zn/Al-layered double hydroxide-quinclorac (Zn/Al-LDH-QC) nanocomposite has been synthesised via co-precipitation method. The versatility of the Zn/Al-LDH enables this host material to be intercalat...

Ferulic acid (FA) was intercalated into zinc layered hydroxide (ZLH) to form a new nanocomposite, namely zinc layered hydroxide-ferulate (ZLH-FA) and was further coated by surfactants sodiu...

Graphene oxide (GO) has been used as a promising material for antimicrobial surface due to its contact-based antimicrobial activity. The antimicrobial activity of GO was thought to be mediated by physical and chemical interactions when sheets come in direct contact with bacterial cells. Antimicrobial surfaces have important applications in the biomedical field for preventing microbial contamination of medical devices, or in environmental systems where bio-fouling is a major cause of increased operation costs in marine transport, membrane-based water treatment, and heat exchangers. It has been reported that, the antimicrobial activity depends up on the size of GO sheets. Herein, In order to know the accurate assessment of the antimicrobial activity of GO through the suspension assays and surface coatings, we used ultrasonic irradiations to tune the size of GO synthesized through an electrochemical exfoliation method assisted by a surfactant, SDS, in a concentration of 0.01 M to study the antimicrobial activity towards a gram-positive bacteria, Enterococcusfaecalis (cocci) and, a gram - negative bacteria, Escherichia coli (rod-shaped). It has been found that, the ultrasonication time has an effect on the introduction of edge-plane sites on the GO sheets, and their effect on the antimicrobial activity.

Research and development in graphene synthesis has been rapidly growing in the past few years because of its extraordinary physical, mechanical, thermal, electrical and optical properties. Graphene flakes, one of the most popular forms of graphene, can be used for many applications such as conductive inks, nanofluids, supercapacitors, composites, etc. Synthesis of graphene flakes is indeed a path to reach large-scale production even if the cost of production and efficiency are required to be further improved. This review sheds light on the recent advancements of graphene flake synthesis and it gives a comprehensive analysis of the synthesis methods. Keys for further improvements are proposed based on the mechanisms involved in the graphene flake formation.

The chemically modified multiwalled carbon nanotubes (MWCNTs) paste electrode with chloroplatinum(II) complex for the determination of mercury is presented. The chloroplatinum(II) complex was characterized by nuclear magnetic resonance spectroscopy (NMR), Fourier transforms infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The capability of the electron transfer rate on the surface of modified electrode evaluated is by electrochemical impedance spectroscopy (EIS). The square wave stripping voltammetry (SWSV) technique was employed to investigate the performance of chloroplatinum(II) complex-MWCNTs paste electrode for determination of mercury. Several operational parameters such as the composition ratios of the electrode, type of supporting electrolyte, pH of the solution, and the SWSV parameters were thoroughly investigated. Under optimal conditions, the linear range obtained was from 5.0 μM to 0.1 mM with limit detection of 3.7 μM. The interference from other heavy metals such as Ca2+, Mg2+, Ni2+, Zn2+, Cd2+, Co2+, Ba2+, Mn2+, and Ce3+ did not influence the electrochemical response. The chloroplatinum(II) complex-MWCNTs paste electrode was successfully applied to determine mercury in skin lightening cosmetics with a good recovery (98.9%–101.1%).

The intercalation of L-phenylalanate (LP) into the interlayer gallery of zinc layered hydroxide (ZLH) has been successfully executed using a simple direct reaction method. The synthesised intercalation compound, zinc layered hydroxide-L-phenylalanate (ZLH-LP), was characterised using PXRD, FTIR, CHNS, ICP-OES, TGA/DTG, FESEM and TEM. The PXRD patterns of the intercalation compound demonstrate an intense and symmetrical peak, indicating a well-ordered crystalline layered structure. The appearance of an intercalation peak at a low angle of 2θ with a basal spacing of 16.3 A, signifies the successful intercalation of the L-phenylalanate anion into the interlayer gallery of the host. The intercalation is also validated by FTIR spectroscopy and CHNS elemental analysis. Thermogravimetric analysis confirms that the ZLH-LP intercalation compound has higher thermal stability than the pristine L-phenylalanine. The observed percentage of L-phenylalanate accumulated release varies in each release media, with 84.5%, 79.8%, 63.8% and 61.8% release in phosphate buffer saline (PBS) solution at pH 4.8, deionised water, PBS solution at pH 7.4 and NaCl solution, respectively. The release behaviour of LP from its intercalation compounds in deionised water and PBS solution at pH 4.8 follows pseudo second order, whereas in NaCl solution and PBS solution at pH 7.4, it follows the parabolic diffusion model. This study shows that the synthesised ZLH-LP intercalation compound can be used for the formation of a new generation of materials for targeted drug release with controlled release properties.

A new compound, namely zinc hydroxide nitrate-3-(4-methoxyphenyl)propionate (ZHN-MPP) nanocomposite, was prepared using the ion exchange and co-precipitation methods. The resulting nanocomposite was composed of the herbicide MPP sandwiched between ZHN inorganic layers. From PXRD results, the intercalation of MPP anions into the interlayer of ZHN was successful, leading to the expansion of the interlayer of ZHN at 26.9 and 26.1 A with the ion exchange and co-precipitation methods respectively. The intercalation of layered material is confirmed by PXRD pattern. FTIR spectra for both nanocomposites revealed the presence of MPP in the interlayer of ZHN-MPP nanocomposites. Based on TGA/DTG analysis, the ZHN-MPP nanocomposite prepared by the ion exchange method was found to have greater thermal stability than the one synthesized by the co-precipitation method. The intercalation was also supported by ICP-OES and CHNO-S analysis, which confirmed the presence of C and Zn in the resultant nanocomposites. The surface analyses of both nanocomposites show mesoporous-type material characteristics. However, the co-precipitation method produced nanocomposite with a higher BET surface area compared to the ion exchange method. Overall, the intercalation process decreased the pore size of the nanocomposite compared to the pristine ZHN. The ion exchange method was proven to produce nanocomposite with higher crystallinity and higher thermal stability, whereas the co-precipitation method was proven to produce nanocomposite with a higher surface area compared to the ion exchange method. This work shows that the nanocomposite ZHN-MPP can be synthesized using the ion exchange and co-precipitation methods for the formation of a new generation of agrochemicals.

Hypothesis: The compatibility of surfactants and graphene surfaces can be improved by increasing the number of aromatic groups in the surfactants. Including aniline in the structure may improve the compatibility between surfactant and graphene further still. Surfactants can be modified by incorporating aromatic groups in the hydrophobic chains or hydrophilic headgroups. Therefore, it is of interest to investigate the effects of employing anilinium based surfactants to disperse graphene nanoplatelets (GNPs) in natural rubber latex (NRL) for the fabrication of electrically conductive nanocomposites. Experiments: New graphene-philic surfactants carrying aromatic moieties in the hydrophilic headgroups and hydrophobic tails were synthesized by swapping the traditional sodium counterion with anilinium. 1 H NMR spectroscopy was used to characterize the surfactants. These custom-made surfactants were used to assist the dispersion of GNPs in natural rubber latex matrices for the preparation of conductive nanocomposites. The properties of nanocomposites with the new anilinium surfactants were compared with commercial sodium surfactant sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and the previously synthesized aromatic tri-chain sodium surfactant TC3Ph3 (sodium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3phenylpropoxy)carbonyl) pentane-2-sulfonate). Structural properties of the nanocomposites were studied using Raman spectroscopy, field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). Electrical conductivity measurements and Zeta potential measurements were used to assess the relationships between total number of aromatic groups in the surfactant molecular structure and nanocomposite properties. The self-assembly structure of surfactants in aqueous systems and GNP dispersions was assessed using small-angle neutron scattering (SANS). Findings: Among these different surfactants, the anilinium version of TC3Ph3 namely TC3Ph3-AN (anilinium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3phenylpropoxy)carbonyl) pentane-2-sulfonate) was shown to be highly efficient for dispersing GNPs in the NRL matrices, increasing electrical conductivity eleven orders of magnitude higher than the neat rubber latex. Comparisons between the sodium and anilinium surfactants show significant differences in the final properties of the nanocomposites. In general, the strategy of increasing the number of surfactant-borne aromatic groups by incorporating anilinium ions in surfactant headgroups appears to be effective.

The effect of incorporating common dodecyl anionic and cationic surfactants such as dodecyltrimethylammonium bromide (DTAB), dodecylethyldimethylammonium bromide (DDAB), and sodium dodecylsulfate (SDS) in nanocomposites of reduced graphene oxide and nanocellulose are described. The stabilization and electrical properties of the nanocomoposites of reduced graphene oxide (RGO) and nanofibrillated kenaf cellulose (NFC) were characterized using four-point probe electrical conductivity measurements. Raman spectroscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy were used to investigate dispersion morphology and the quality of RGO inside the NFC matrices. Small-angle neutron scattering (SANS) was used to study the aggregation behavior of the aqueous surfactant systems and RGO dispersions. The cationic surfactant DTAB proved to be the best choice for stabilization of RGO in NFC, giving enhanced electrical conductivity five orders of magnitude higher than the neat NFC. The results highlight the effects of hydrophilic surfactant moieties on the structure, stability and properties of RGO/NFC composites.

A technology for converting waste materials to high quality large-area monolayer graphene film can be significant and thereby obtaining high value-added product. Here, we revealed the transformation of waste chicken fat into uniform monolayer graphene film on re-solidified Cu by a low pressure chemical vapor deposition (LPCVD) technique. The evolve gas analyzer-gas chromatography⿿mass spectrometry (EGA-GC⿿MS) analysis of chicken fat oil showed that the free fatty acid in chicken oil decomposed into a short hydrocarbon chains which makes it favorable to use as a carbon precursor for graphene synthesis. Growth of uniform monolayer graphene film on the re-solidified Cu was confirmed by Raman mapping, where 2D to G peak intensity ratio (I2D/IG) is 3.0 at most of the area. Thus, the use of waste from poultry industry as a carbon source instead of commonly used hydrocarbon gas sources for graphene synthesis can be an approach for green nanotechnology.

Layered double hydroxides and layered hydroxide salts have generated enormous excitement in the inorganic field due to their potential to act as versatile host materials in fabricating novel host–guest layered materials. The ability of the layered hydroxide anion exchanger to be incorporated with a wide range of guest ions enable them to be exploited in various applications related to pesticides. This review sums up the different methods of preparing layered hydroxide anion exchanger, summarises the types of anion intercalated into these layered hydroxide anion exchanger based on their respective systems, and elucidates their potential applications in pesticide-related fields.

Magnesium layered hydroxide (MLH) intercalated with anionic 3-(4-methoxyphenyl)propionic acid (MPP) was synthesised by a direct reaction method using magnesium oxide and MPP as precursors. A further coating of chitosan was applied on the external surface of MLH–MPP nanocomposite to form a new material, named MLH–MPP/chitosan nanocomposite. The XRD pattern showed an intense and sharp peak at basal spacing 18.9 A, proving that MPP anions were successfully intercalated into the interlayer gallery of MLH in a monolayer arrangement. The XRD pattern of the MLH–MPP/chitosan nanocomposite shows similar peaks with the MLH–MPP nanocomposite. The result was also supported by FTIR spectra and elemental analysis. TGA/DTG spectra showed that the thermal stabilities of the guest anion in the both nanocomposites were markedly enhanced. A controlled-release study of the MPP ion from the MLH–MPP/chitosan nanocomposite showed a slower release compared to MLH–MPP nanocomposite with an initial rapid release and slow r...

In the present work, the feasibility of chitosan-graphene oxide (CS-GO) nanocomposites, namely CS-GO 1% (w/w), CS-GO 2% (w/w) and CS-GO 3% (w/w) as water-solubilising agents for rotenone pesticide was evaluated for the first time. The CS-GO nanocomposites were characterised by using FTIR, SEM, TEM and XRD analyses. The interaction of nanocomposites with rotenone was investigated through adsorption study involving several experimental parameters such as solution pH, initial concentration and contact time. Additionally, the desorption study was carried out using HCl and NaOH as desorption agents. Based on correlation coefficient (R2), the adsorption kinetic data were best described by the pseudo-first order equation while the adsorption equilibrium data were correlated well with the Langmuir isotherm model. The GO nanoparticle aggregates have a spherical shape with size ranged from 1.40 to 34.7 nm. The crystallinity of CS was increased following interaction with GO, whereby the intensity of diffractive peak at 2θ = 20.42° was increased to more than 4000 counts. Based on Langmuir isotherm model, CS-GO 3% (w/w) exhibited the highest adsorption capacity for rotenone with Q value of 92.59 mg/g. The main mechanism for interaction of CS-GO nanocomposites with rotenone was through formation of hydrogen bond. The presence of -OH, -COOH and -NH functional groups on CS-GO nanocomposites significantly contributed to water-solubilising mechanism. The CS-GO 1% (w/w), CS-GO 2% (w/w) and CS-GO 3% (w/w) nanocomposites were able to increase the solubility of rotenone in water by 34.40%, 38.80% and 46.30%, respectively.

Controlled release formulations of herbicides have been recognised to have potential in reducing the adverse effects of conventional herbicides on our environment. In this work, the controlled release behaviour of quinclorac (QC) from zinc/aluminium-layered double hydroxide-quinclorac (Zn/Al-LDH-QC) and its chitosan-coated composite Zn/Al-LDH-QC-Chi into aqueous solutions of Na3PO4, Na2SO4 and NaCl were studied. The physicochemical properties of both composites were studied initially, using powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR), thermogravimetric and derivative thermogravimetric analysis (TGA/DTG) and field emission scanning electron microscopy (FESEM) instruments, so that the effect of chitosan coating on their functional groups, thermal stabilities and surface morphology could be observed thoroughly. The results from the release studies showed that the presence of chitosan as a coating enhances the electrostatic attraction between the positively charged amino groups on the backbone of chitosan and the negatively charged QC anions, thus assisting in prolonging the time of release of QC. The kinetic studies revealed that both Zn/Al-LDH-QC and Zn/Al-LDH-QC-Chi composites obey second-order mechanisms, thus signifying that the release of QC into the release media by both composites took place via dissolution and ion exchange. These results therefore indicate the promising potential of Zn/Al-LDH-QC and Zn/Al-LDH-QC-Chi to overcome the drawbacks of the over-use of herbicides in paddy cultivation areas.

Graphene is a single layer of carbon atoms arranged in an sp2-hybridized structure with properties far superior compared to other materials. Research and development in graphene synthesis have been rapidly growing the past few years, especially using chemical vapor deposition (CVD) over various types of carbon precursor. The nature and the type of carbon precursor is one important parameter of growth by CVD, especially for graphene production, since they can dramatically impact graphene growth yield and rate. However, effects of the used carbon precursor on graphene growth mechanisms are rarely discussed. In the course of large-scale and low-cost graphene preparation, this review on the recent trends regarding the utilization of diverse carbon precursors used to synthesize graphene via the CVD method is of great interest for development of improved or alternative synthesis methods. The details and the mechanisms involved in graphene synthesis using carbon precursors in the form of gaseous, liquids and solids are compared, analyzed and discussed thoroughly. In this review, we present a thorough overview on the impact and mechanisms of carbon precursors in achieving high-quality graphene with competitive edge in the near future.

The article addresses the role of surfactant headgroup structure on hybrid surfactant performance for water-in-CO2 (w/c) microemulsion stabilization. The synthetic procedure, aqueous properties, and phase behaviour of a new hybrid sulfoglutarate surfactant are described. The sulfoglutarate version has an extra methylene group incorporated into the hydrophilic headgroup. The related hydrocarbon (AOT14 and AOT14GLU) and fluorocarbon (di-CF2 and di-CF2GLU) surfactants were used to form w/c microemulsions. For these two groups, the aqueous properties and w/c phase stability of both sulfoglutarates and sulfosuccinates were found to be similar. The newly synthesized hybrid CF2/AOT14GLU (sodium (4H,4H,5H,5H,5H-pentafluoropentyl-2,2-dimethyl-1-propyl)-2-sulfoglutarate) proved to be more efficient than the normal sulfosuccinate, hybrid CF2/AOT14 in terms of the aqueous behaviour and w/c phase stability. Hybrid CF2/AOT14GLU more effectively decreased the air-water surface tension by ∼2 mN m−1 and lowering the cloud pressures on CO2 by ∼150 bar.

Graphene is the newest member of the carbon family, and has revolutionized materials science especially in the field of polymer nanocomposites. However, agglomeration and uniform dispersion remains an Achilles' heel (even an elephant in the room), hampering the optimization of this material for practical applications. Chemical functionalization of graphene can overcome these hurdles but is often rather disruptive to the extended pi-conjugation, altering the desired physical and electronic properties. Employing surfactants as stabilizing agents in latex technology circumvents the need for chemical modification allowing for the formation of nanocomposites with retained graphene properties. This article reviews the recent progress in the use of surfactants and polymers to prepare graphene/polymer nanocomposites via latex technology. Of special interest here are surfactant structure-performance relationships, as well as background on the roles surfactant-graphene interactions for promoting stabilization.

Zinc-oxide (ZnO) nanorod arrays were successfully prepared by using dual sonication sol–gel process. Field emission scanning electron microscopy revealed that the nanorods exhibited a hexagonal structure with a flat-end facet. The nanorods displayed similar surface morphologies and grew uniformly on the seed layer substrate, with the average diameter slightly increasing to the range of 65 to 80 nm after being immersed for varying growth times. Interestingly, thickness measurements indicated that the thicknesses of the samples increased as the growth time was extended. In addition, the X-ray diffraction spectra indicated that the prepared ZnO nanorods with a hexagonal wurtzite structure grew preferentially along the c-axis. Therefore, we can conclude that the diameter, length, and orientation of the ZnO nanorod arrays along the c-axis are controllable by adjusting the growth time, motivating us to further explore the growth mechanisms of ZnO nanorods.

Hypothesis: Graphene nanoplatelets (GNPs) can be dispersed in natural rubber matrices using surfactants. The stability and properties of these composites can be optimized by the choice of surfactants employed as stabilizers. Surfactants can be designed and synthesized to have enhanced compatibility with GNPs as compared to commercially available common surfactants. Including aromatic groups in the hydrophobic chain termini improves graphene compatibility of surfactants, which is expected to increase with the number of aromatic moieties per surfactant molecule. Hence, it is of interest to study the relationship between molecular structure, dispersion stability and electrical conductivity enhancement for single-, double-, and triple-chain anionic graphene-compatible surfactants. Experiments: Graphene-philic surfactants, bearing two and three chains phenylated at their chain termini, were synthesized and characterized by proton nuclear magnetic resonance (1H NMR) spectroscopy. These were used to formulate and stabilize dispersion of GNPs in natural rubber latex matrices, and the properties of systems comprising the new phenyl-surfactants were compared with commercially available surfactants, sodium dodecylsulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS). Raman spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and high-resolution transmission electron microscopy (HRTEM) were used to study structural properties of the materials. Electrical conductivity measurements and Zeta potential measurements were used to assess the relationships between surfactant architecture and nanocomposite properties. Small-angle neutron scattering (SANS) was used to study self-assembly structure of surfactants. Findings: Of these different surfactants, the tri-chain aromatic surfactant TC3Ph3 (sodium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3phenylpropoxy)carbonyl) pentane-2-sulfonate) was shown to be highly graphene-compatible (nanocomposite electrical conductivity = 2.22 × 10−5 S cm−1), demonstrating enhanced electrical conductivity over nine orders of magnitude higher than neat natural rubber-latex matrix (1.51 × 10−14 S cm−1). Varying the number of aromatic moieties in the surfactants appears to cause significant differences to the final properties of the nanocomposites.