Evaluation of in vitro corrosion behavior and biocompatibility of poly[xylitol-(1,12-dodecanedioate)](PXDD)-HA coated porous iron for bone scaffolds applications

The present study evaluates the corrosion behavior of poly[xylitol-(1,12-dodecanedioate)](PXDD)-HA coated porous iron (PXDD140/HA-Fe) and its cell-material interaction aimed for temporary bone scaffold applications. The physicochemical analyses show that the addition of 20 wt.% HA into the PXDD polymers leads to a higher crystallinity and lower surface roughness. The corrosion assessments of the PXDD140/HA-Fe evaluated by electrochemical methods and surface chemistry analysis indicate that HA decelerates Fe corrosion due to a lower hydrolysis rate following lower PXDD content and being more crystalline. The cell viability and cell death mode evaluations of the PXDD140/HA-Fe exhibit favorable biocompatibility as compared to bare Fe and PXDD-Fe scaffolds owing to HA's bioactive properties. Thus, the PXDD140/HA-Fe scaffolds possess the potential to be used as a biodegradable bone implant.

Preparation and Characterization of Biodegradable Sponge-like Cryogel Particles of Chitosan via the Inverse Leidenfrost (iLF) Effect

Chitosan-based cryogel particles were synthesized using the inverse Leidenfrost (iLF) effect, with glutaraldehyde employed as the cross-linker. The resulting cryogels exhibited a sponge-like morphology with micrometer-sized interconnected pores and demonstrated resilience, withstanding up to three compression-release cycles. These characteristics highlight the potential of chitosan cryogels for diverse applications, including adsorption and biomedical uses. We further investigated the influence of varying acetic acid concentrations on the properties of the chitosan cryogels. Our findings revealed that the particle size distribution of the cryogels ranged from 1300 to 2900 μm. As the concentration of acetic acid increased, the swelling degree of the chitosan cryogels decreased, stabilizing at an approximate value of around 6 at 0.03 mol of acetic acid. Additionally, the shift in the absorption peak of the OH and free amino groups from 3261 to 3404 cm-1 confirmed the cross-linking reaction between chitosan and glutaraldehyde.

Elucidating the alkene hydrogenation reaction based on cotton textile reduced graphene oxide under the influence of external electric field: Illustration of new noble method

The hydrogenation reaction of alkene is one of the most used industrial chemical process for various materials of daily life and energy consumption. This is a heterogeneous reaction and traditionally carried out by metallic catalysis. However, these conventional catalytic hydrogenations of alkene suffer from various setbacks such as catalyst poisoning, less recyclability and are environmentally unfriendly. Therefore, in recent years, researchers have been trying to develop the alternatives to metal catalysis hydrogenation of alkene. Heterogeneous catalysis under the external electric field is considered the future of green catalysis. In this paper, we report a comprehensive investigation dealing with the theoretical basis for simulating the phenomenon of heterogeneous catalysis, on a molecular level, under an external electric field. The illustration of the prospect as well as the effects of the mostly used catalytic systems, reduced graphene oxide, under the influence of external electric fields is provided. Moreover, a noble method of alkene hydrogenation reaction based on cotton textile reduced graphene oxide (CT-RGO) under the influence of an external electric field is introduced. The corresponding theoretical investigation was carried out within the framework of the density functional theory (DFT) method using first-principles calculations. The study has been carried out by elucidating DFT calculations for three different proposed catalytic systems, namely without electricity, with electricity and with an external electric field of 2 milli-Atomic unit. The obtained results indicate that adsorption energy of H₂ on the CT-RGO surface is significantly higher when the electric field is applied along the bond axis, suggesting thereby that hydrogenation of alkene can be induced with CT-RGO catalyst support under external electric fields. The obtained results shed light on the effect of the external electricity field on the graphene-hydrogen complex, the activation energy of graphene radicals to achieve the transition states as well as the adsorption of the hydrogen atoms over the graphene surface. Altogether, the theoretical results presented herein suggested that the proposed catalytic system holds promise for facilitating the alkene hydrogenation under external electric fields.

Bibliometric Analysis of Publications of Universiti Teknologi Malaysia

This study analyses the scholarly publications of Universiti Teknologi Malaysia (UTM) in conjunction with 50 years of UTM establishment. A bibliometric analysis is performed to analyse the UTM’s publication and research trends over the 50 years, especially during the post-research university (RU) period, publications impacts, subject area expertise and publications performance in comparison to other RU. Based on the analysis, engineering and computer science are the most prominent fields among the research fields in UTM in terms of a number of publications and citations thus far. Among the top 10 fields in UTM, materials science, chemical engineering, energy and chemistry areas are seen to have a high potential to further excel in citation provided that the publication numbers of these fields are further increased. The publications output for some UTM fields can still be considered low despite having a reasonable number of authors and talents. UTM is the top university in the number of publications from 2015 till 2020 in four fields, namely engineering, computer science, materials science, and chemical engineering, compared to other RU.

Modifications on porous absorbable Fe-based scaffolds for bone applications: A review from corrosion and biocompatibility viewpoints

Iron (Fe) and Fe-based scaffolds have become a research frontier in absorbable materials which is inherent to their promising mechanical properties including fatigue strength and ductility. Nevertheless, their slow corrosion rate and low biocompatibility have been their major obstacles to be applied in clinical applications. Over the last decade, various modifications on porous Fe-based scaffolds have been performed to ameliorate both properties encompassing surface coating, microstructural alteration via alloying, and advanced topologically order structural design produced by additive manufacturing (AM) techniques. The recent advent of AM produces topologically ordered porous Fe-based structures with an optimized architecture having controllable pore size and strut thickness, intricate internal design, and larger exposed surface area. This undoubtedly opens up new options for controlling Fe corrosion and its structural strengths. However, the in vitro biocompatibility of the AM porous Fe still needs to be addressed considering its higher corrosion rate due to the larger exposed surface area. This review summarizes the latest progress of the modifications on porous Fe-based scaffolds with a specific focus on their responses on the corrosion behavior and biocompatibility.

Hierarchical Structure and Magnetic Behavior of Zn-Doped Magnetite Aqueous Ferrofluids Prepared from Natural Sand for Antibacterial Agents

This study performs natural sand-based synthesis using the sonochemical route for preparing Zn-doped magnetite nanoparticles. The nanoparticles were dispersed in water as a carrier liquid to form Zn-doped magnetite aqueous ferrofluids. Structural data analysis indicated that the Zn-doped magnetite nanoparticles formed a nanosized spinel structure. With an increase in the Zn content, the lattice parameters of the Zn-doped magnetite nanoparticles tended to increase because Zn2+ has a larger ionic radius than those of Fe3+ and Fe2+. The existence of Zn-O and Fe-O functional groups in tetrahedral and octahedral sites were observed in the wavenumber range of 400-700 cm-1. The primary particles of the Zn-doped magnetite ferrofluids tended to construct chain-like structures with fractal dimensions of 1.2-1.9. The gas-like compression (GMC) plays as a better model than the Langevin theory to fit the saturation magnetization of the ferrofluids. The ferrofluids exhibited a superparamagnetic character, with their magnetization was contributed by aggregation. The Zn-doped magnetite ferrofluids exhibited excellent antibacterial activity against gram-positive and negative bacteria. It is suggested that the presence of the negatively charged surface and the nanoparticle size may contribute to the high antibacterial activity of Zn-doped magnetite ferrofluids and making them potentially suitable for advanced biomedical.

Insight into the bioabsorption of Fe-based materials and their current developments in bone applications

Iron (Fe) and Fe-based materials have been vigorously explored in orthopedic applications in the past decade mainly owing to their promising mechanical properties including high yield strength, elastic modulus and ductility. Nevertheless, their corrosion products and low corrosion kinetics are the major concerns that need to be improved further despite their appealing mechanical strengths. The current studies on porous Fe-based scaffolds show an improved corrosion rate but the in vitro biocompatibility is still problematic in general. Unlike the Mg implants, the biodegradation and bioabsorption of Fe-based implants are still not well described. This vague issue could implicate the development of Fe-based materials as potential medical implants as they have not reached the clinical trial stage yet. Thus, there is a need to understand in-depth the Fe corrosion behavior and its bioabsorption mechanism to facilitate the material design of Fe-based scaffolds and further improve its biocompatibility. This manuscript provides an important insight into the basic bioabsorption of the multi-ranged Fe-based corrosion products with a review of the latest progress on the corrosion & in vitro biocompatibility of porous Fe-based scaffolds together with the remaining challenges and the perspective on the future direction.

Green Synthesized Silver Nanoparticles Immobilized on Activated Carbon Nanoparticles: Antibacterial Activity Enhancement Study and Its Application on Textiles Fabrics

This research aimed to enhance the antibacterial activity of silver nanoparticles (AgNPs) synthesized from silver nitrate (AgNO3) using aloe vera extract. It was performed by means of incorporating AgNPs on an activated carbon nanoparticle (ACNPs) under ultrasonic agitation (40 kHz, 2 × 50 watt) for 30 min in an aqueous colloidal medium. The successful AgNPs synthesis was clarified with both Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectrophotometers. The successful AgNPs-ACNPs incorporation and its particle size analysis was performed using Transmission Electron Microscope (TEM). The brown color suspension generation and UV-Vis's spectra maximum wavelength at around 480 nm confirmed the existence of AgNPs. The particle sizes of the produced AgNPs were about 5 to 10 nm in the majority number, which collectively surrounded the aloe vera extract secondary metabolites formed core-shell like nanostructure of 8.20 ± 2.05 nm in average size, while ACNPs themselves were about 20.10 ± 1.52 nm in average size formed particles cluster, and 48.00 ± 8.37 nm in average size as stacking of other particles. The antibacterial activity of the synthesized AgNPs and AgNPs-immobilized ACNPs was 57.58% and 63.64%, respectively (for E. coli); 61.25%, and 93.49%, respectively (for S. aureus). In addition, when the AgNPs-immobilized ACNPs material was coated on the cotton and polyester fabrics, the antibacterial activity of the materials changed, becoming 19.23% (cotton; E. coli), 31.73% (polyester; E. coli), 13.36% (cotton; S. aureus), 21.15% (polyester; S. aureus).

Degradation-triggered release from biodegradable metallic surfaces

This work is dedicated to the investigation of drug-release control by a direct effect of degradation from biodegradable metallic surfaces. Degradation behaviors characterized by surface morphology, immersion, and electrochemical techniques demonstrated that curcumin-coated zinc (c-Zn) had a higher degradation rate compared to curcumin-coated Fe (c-Fe). High anodic dissolution rate due to the higher degradation rate and widely extended groove-like degradation structure of c-Zn propelled a higher curcumin release. On the other hand, a slower curcumin release rate shown by c-Fe scaffolds is ascribed to its lower anodic dissolution and to its pitting degradation regime with relatively smaller pits. These findings illuminate the remarkable advantage of different degradation behaviors of degradable metallic surfaces in directly controlling the drug release without the need for external electrical stimulus.

Photocatalytic remediation of organic waste over Keggin-based polyoxometalate materials: A review

Photocatalytic remediation of industrial water pollution has courted intense attention lately due to its touted green approach. In this respect, Keggin-based polyoxometalates (POMs) as green solid acids in photocatalytic reaction possess superior qualities, viz. unique photoinduced charge-transfer properties, strong photooxidative-photoreductive ability, high chemical and thermal stability, and so forth. Unfortunately, it suffers from a large bandgap energy, low specific surface area, low recoverability, and scarce utilization in narrow absorption range. Therefore, the pollutant degradation performance is not satisfactory. Consequently, multifarious research to enhance the photocatalytic performance of Keggin-based POMs were reported, viz. via novel modifications and functionalizations through a variety of materials, inclusive of, inter alia, metal oxides, transition metals, noble metals, and others. In order to advocate this emerging technology, current review work provides a systematic overview on recent advancement, initiated from the strategized synthetic methods, followed by hierarchical enhancement and intensification process, at the same time emphasizes on the fundamental working principles of Keggin-based POM nanocomposites. By reviewing and summarizing the efforts adopted global-wide, this review is ended with providing useful outlooks for future studies. It is also anticipated to shed light on producing Keggin-based POM nanocomposites with breakthrough visible- and solar-light-driven photocatalytic performance against recalcitrant organic waste.

Electrospun Nano-Fibers for Biomedical and Tissue Engineering Applications: A Comprehensive Review

Pharmaceutical nano-fibers have attracted widespread attention from researchers for reasons such as adaptability of the electro-spinning process and ease of production. As a flexible method for fabricating nano-fibers, electro-spinning is extensively used. An electro-spinning unit is composed of a pump or syringe, a high voltage current supplier, a metal plate collector and a spinneret. Optimization of the attained nano-fibers is undertaken through manipulation of the variables of the process and formulation, including concentration, viscosity, molecular mass, and physical phenomenon, as well as the environmental parameters including temperature and humidity. The nano-fibers achieved by electro-spinning can be utilized for drug loading. The mixing of two or more medicines can be performed via electro-spinning. Facilitation or inhibition of the burst release of a drug can be achieved by the use of the electro-spinning approach. This potential is anticipated to facilitate progression in applications of drug release modification and tissue engineering (TE). The present review aims to focus on electro-spinning, optimization parameters, pharmacological applications, biological characteristics, and in vivo analyses of the electro-spun nano-fibers. Furthermore, current developments and upcoming investigation directions are outlined for the advancement of electro-spun nano-fibers for TE. Moreover, the possible applications, complications and future developments of these nano-fibers are summarized in detail.

SEM, XRD and FTIR analyses of both ultrasonic and heat generated activated carbon black microstructures

The microstructures of the activated carbon black microparticles (ACBMPs) generated through both treatments of 20 min ultrasonic and 400 °C thermal energy equivalent have been analyzed properly using scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier-transformed infrared (FTIR) spectroscopy methods. The research was aiming to generate binding or active sites points on the outer surface of the ACBMPs body of which commonly plays an important role in both adsorption and catalytic processes. It was observed that around 150 nm up to 400 nm in average diameter super macro voids with many various turns of nano-scale wells, and around 1.84 angstrom (Å) up to 15.98 Å intraparticle pores were generated. In addition, the parallel planes spacing of the carbonaceous framework sheets, namely d hkl in Miller indexes terminology, of about 4.44 Å up to 2.98 Å constructed the inner particles of the ACBMPs body. A new nomenclature method for the binding or active site shapes identification and classifying them into four categories based on the quadrants terminology, i.e. quadrant one (Q1), two (Q2), three (Q3) and four (Q4) is proposed. Each the quadrants contains four categories of turns types, i.e. sharp, semi sharp, obtuse and non-significant turns depending on the angle of the associated turn in radian angle, θ. Finally, it can be concluded that the combination of ultrasonic and thermal energy treatments in fabricating ACBMPs could generate binding or active site points with unique shapes as a transit terminal for any guest molecules, in this context is methyl red (MR) molecules to enter into the suitable intra-particles pores of the ACBMPs body.

Highly Crystalline Zinc Oxide/Mesoporous Hollow Silica Composites Synthesized at Low Temperature for the Photocatalytic Degradation of Sodium Dodecylbenzenesulfonate

Highly crystalline ZnO/mesoporous hollow silica sphere (MHSS) composites have been successfully synthesized through an impregnation method at 323K without applying calcination. Three composites of different Zn/Si molar ratios of 1:2, 1:1, and 2:1 were prepared. X-Ray diffraction patterns confirmed the presence of highly crystalline ZnO in the materials. A layer of ZnO was formed on the MHSS as evidenced by field emission scanning electron microscopy analysis. Transmission electron microscopy analysis verified the mesoporous structure in ZnO/MHSS composites. N2 adsorption–desorption analysis indicated a type IV isotherm for 1ZnO/2MHSS and 1ZnO/1MHSS samples, confirming the presence of mesopores in the ZnO layer. It has been demonstrated that all the ZnO/MHSS composites exhibit a high photocatalytic activity towards sodium dodecylbenzenesulfonate degradation compared with bare ZnO under UV irradiation. A kinetic study showed that the photodegradation followed a second order model. Among the prepared composites, 1ZnO/1MHSS recorded the highest reaction rate of 6.03×10−3mM−1min−1 which is attributed to a high crystallinity and the monodispersity of a high amount of ZnO on MHSS.

Synthesis and characterization of zeolite NaX from Bangka Belitung Kaolin as alternative precursor

The potential use of kaolin as silica and alumina precursor for the synthesis of zeolite NaX was investigated in this study. The synthesis involved three steps of reactions; the preparation of seed gel, the formation of feedstock gel using kaolin and the combination of overall gel followed by hydrothermal treatment at 105°C for 12 hours. Analysis using X-ray Diffraction (XRD) method indicated the transformation of kaolin into pure phase zeolite NaX with a small amount of kaolin was still visible. Detail microscopic analysis showed the morphology of zeolite X consisted of octahedral particles with a crystallite diameter of 20-30 µm. Analysis of surface acidity using pyridine as probe molecule indicated the zeolite X has high Brǿnsted acidity with 0.181 mmol/g of acid sites, significantly higher than Lewis acidity ~0.053 mmol/g. The N2 adsorption-desorption measurement indicated a type IV material with both microporous and mesoporous structures with an average pore size of 1.47 nm for micropore and 3.41 nm for mesoporous.

One-Dimensional-Like Titania/4'-Pentyl-4-Biphenylcarbonitrile Composite Synthesized Under Magnetic Field and its Structure-Photocatalytic Activity Relationship

The demonstration of the structure-properties relationship of shape-dependent photocatalysts remains a challenge today. Herein, one-dimensional (1-D)-like titania (TiO₂), as a model photocatalyst, has been synthesized under a strong magnetic field in the presence of a magnetically responsive liquid crystal as the structure-aligning agent to demonstrate the relationship between a well-aligned structure and its photocatalytic properties. The importance of the 1-D-like TiO₂ and its relationship with the electronic structures that affect the electron-hole recombination and the photocatalytic activity need to be clarified. The synthesis of 1-D-like TiO₂ with liquid crystal as the structure-aligning agent was carried out using the sol-gel method under a magnetic field (0.3 T). The mixture of liquid crystal, 4'-pentyl-4-biphenylcarbonitrile (5CB), tetra-n-butyl orthotitanate (TBOT), 2-propanol, and water, was subjected to slow hydrolysis under a magnetic field. The TiO₂-5CB took a well-aligned whiskerlike shape when the reaction mixture was placed under the magnetic field, while irregularly shaped TiO₂-5CB particles were formed when no magnetic field was applied. It shows that the strong interaction between 5CB and TBOT during the hydrolysis process under a magnetic field controls the shape of titania. The intensity of the emission peaks in the photoluminescence spectrum of 1-D-like TiO₂-5CB was lowered compared with the TiO₂-5CB synthesized without the magnetic field, suggesting the occurrence of electron transfer from 5CB to the 1-D-like TiO₂-5CB during ultraviolet irradiation. Apart from that, direct current electrical conductivity and Hall effect studies showed that the 1-D-like TiO₂ composite enhanced electron mobility. Thus, the recombination of electrons and holes was delayed due to the increase in electron mobility; hence, the photocatalytic activity of the 1-D-like TiO₂ composite in the oxidation of styrene in the presence of aqueous hydrogen peroxide under UV irradiation was enhanced. This suggests that the 1-D-like shape of TiO₂ composite plays an important role in its photocatalytic activity.

Effect of magnetic field on the synthesis of well-aligned TiO2-5CB by sol-gel method

This paper describes the approach by using a magnetic field as a technique in order to synthesize well-aligned materials. The magnetic field technique could be a potential method because it has advantage that all of the materials could be aligned by magnetic field as long as they have magnetic anisotropy. The aim of this research is to explore the effects of magnetic field and magnetic line in the synthesis of well-aligned material, namely titania (TiO2).  The synthesis of well-aligned titania with liquid crystal as the structure-aligning agent is demonstrated under magnetic field in the presence of liquid crystal, 4′-pentyl-4-biphenylcarbonitrile (5CB), tetra-n-butyl orthotitanate (TBOT), 2-propanol and water. The mixture underwent slow hydrolysis and drying process under magnetic field (0.3 T) in ambient condition. The use of magnetic field and 5CB liquid crystal as the structure aligning agent has led to the successful formation of well-aligned TiO2-5CB via sol-gel method. When no magnetic field was applied, the TiO2-5CB obtained was spherical in shape and no alignment can be observed. This study demonstrated that magnetic field can play an important role in the synthesis of well-aligned TiO2-5CB.

High voltage powder spray coating as a new method for the preparation of carbon-titania coated stainless steel

High voltage powder spray coating (HVPSC) is one of the methods used for coating substrate with polymer powder in industries. This study utilizes HVPSC as a new deposition method of carbon-based powdered materials on stainless steel. Carbon-titania (C/TiO2) coated stainless steel was successfully prepared from the mixture of epoxide and titania powder, sprayed onto stainless steel plate using HVPSC, followed by pyrolysis at 300 °C under nitrogen atmosphere. The functional group of C/TiO2 was confirmed by Fourier transform infrared (FTIR) spectroscopy, where the FTIR spectrum showed the presence of C─H sp3, C═O, C─O, and Ti─O peaks. The morphology of the C/TiO2 sample studied using field emission scanning electron microscopy (FESEM) clearly shows that the particles of TiO2 were coated with carbon on their surface.  The coating performance was evaluated through the abrasion test and showed no weight loss. Adhesion of C/TiO2 coating was also tested in the peel adhesion test and the result showed that the attachment of C/TiO2 on the stainless steel is very strong. It has been proven that the HVPSC method is not only a simple technique to coat materials but also a very durable one

Direct synthesis of ZSM-5 from kaolin and the influence of organic template

We investigated the transformation of kaolin to ZSM-5 using hydrothermal synthesis method and the influence of organic template as a structure-directing agent.  The formation of ZSM-5 from kaolin occurred via dissolution of kaolin to form amorphous silica. Zeolite-like analcime produced when the hydrothermal treatment was extended to 18 h. We found synergistic effect of using a mixture of TPAOH and TPABr organic template to enhance kaolin dissolution, initiate ZSM-5 formation and inhibit the transformation of ZSM-5 to analcime.

Titania-Loaded Coal Char as Catalyst in Oxidation of Styrene with Aqueous Hydrogen Peroxide

Titania-loaded coal char catalyst was successfully prepared. The preparation steps involved pyrolysis of low rank coal at different temperatures and durations, sulfonation, impregnation of titanium(IV) isopropoxide, and then heating at 110 °C. It is found that the coal chars’ surfaces were rough after sulfonation and impregnation, while large pore volume, high surface area and carbon composition were observed at low pyrolysis temperature for short duration. These properties contributed to high selectivity towards benzaldehyde (> 90 %) at 600 °C (0.5–2 h)) in styrene oxidation using aqueous hydrogen peroxide as the oxidant.

Can kaolin function as source of alumina in the synthesis of ZSM-5 without an organic template using a seeding technique?

ZSM-5 has been successfully synthesized by hydrothermal method using Indonesian Bangka kaolin as the aluminium source without an organic template and preactivation by calcination utilizing silicalite and ZSM-5 seedings. There are three parameters that made kaolin a very suitable aluminium source in the synthesis of ZSM-5 by using this method. The first parameter was the presence of types of seeds (silicalite and ZSM-5). Secondly, the molar ratio of Si/Al was in the range of 40–60. Thirdly, the concentrations of NaOH were varied from 6 to 12 mol with 1800 mol water. Interestingly, the use of silicalite seed produced pure ZSM-5 zeolite, whereas analcime and mordenite appeared as side products when ZSM-5 was used as the seed. The above effects can be illustrated by the following mechanism. Kaolin was fully dissolved in the basic mixture solution containing concentrated NaOH and silica sols, and followed by the crystallization in the presence of seeds (silicalite and ZSM-5). The mechanism was postulated on the basis of XRF, XRD, 29Si and 27Al MAS NMR analyses.

Imazalil sulphate pesticide degradation using silver loaded hollow anatase TiO2 under UV light irradiation

Silver loaded hollow anatase TiO2 particles with the location of silver are inside (Ag@TiO2) and outside (Ag/TiO2) the hollow TiO2 structure have been successfully synthesized by a deposition-precipitation and template methods. The effects of silver nanoparticles location on Ag@TiO2 andAg@TiO2 has been evaluated in the photodegradation efficiency of imazalil sulphate pesticide in aqueous suspension under ultraviolet irradiation. The Ag/TiO2 showed better photocatalytic performance for the degradation of imazalil sulphate, compared to Ag@TiO2 and hollow TiO2 microspheres. A higher photocatalytic activity of Ag/TiO2 compared to Ag@TiO2 and hollow TiO2 can be considered as an evidence of enhanced charge separation of Ag/TiO2  photocatalyst as confirmed by photoluminescence spectroscopy.

New Face of MJFAS

The Malaysian Journal of Fundamental and Applied Sciences (MJFAS), has come a long way since its beginnings in 2005 when six papers appeared in the first issue. As the Editor-in-Chief of the Malaysian Journal of Fundamental and Applied Sciences, I am writing to invite you to submit your most important research to the Journal. We envision the Journal as the best place to publish all of the levels of research in fundamental and applied sciences from all over the world, especially from researchers in Malaysia dan Indonesia. Working with our knowledgeable and international Editorial Board members and I can assure you of a rapid, robust and fair peer-review process.As the Malaysian Journal of Fundamental and Applied Sciences is now indexed by Thomson Reuters Web of Science, we are especially aiming to reduce time to decision. We also have begun to work towards raising the Journal’s impact factor. For the coming submissions, the Malaysian Journal of Fundamental and Applied Sciences will start implementing the "Your Paper, Your Way" initiative. In this way, authors can focus on the scientific quality of the paper. Journal-specific formatting such as reference style is no longer needed. The Malaysian Journal of Fundamental and Applied Sciences is now entering its twelfth year and it is now the official journal of the Indonesia-Malaysia Research Consortium (I'M Research Consortium). The consortium's aims are to foster the development of the field through a crossdisciplinary approach and to reach consensus in areas of common interest in fundamental and applied sciences field. By making the Malaysian Journal of Fundamental and Applied Sciences the official journal of the I'M Research Consortium, we hope to provide a forum to bring together society members and to publish peer-reviewed consensus documents that emerge from the activities of the consortium. The year of 2016 marks the next in a series of regular changes to the Editorial Board. Several of the Editorial Board members have been with the journal for a large part of its development and have been responsible for its success through their contributions both as authors as well as reviewers and advisors. In the course of 2016, the Malaysian Journal of Fundamental and Applied Sciences launched its Facebook page (see www.facebook.com/mjfas2016), providing its readers with information about events of general interest to researchers and scientists as well as details and links to papers and research featured in the Malaysian Journal of Fundamental and Applied Sciences. Thank you in advance for your valuable contributions to the Malaysian Journal of Fundamental and Applied Sciences.  

Photocatalytic activity and reusability of ZnO layer synthesised by electrolysis, hydrogen peroxide and heat treatment

In this study, the zinc oxide (ZnO) layer was synthesised on the surface of Zn plates by three different techniques, i.e. electrolysis, hydrogen peroxide and heat treatment. The synthesised ZnO layers were characterised using scanning electron microscopy, X-ray diffraction, UV-visible diffuse reflectance and photoluminescence spectroscopy. The photocatalytic activity of the ZnO layer was further assessed against methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB was achieved up to 84%, 79% and 65% within 1 h for ZnO layers synthesised by electrolysis, heat and hydrogen peroxide treatment, respectively. The reusability results show that electrolysis and heat-treated ZnO layers have considerable photocatalytic stability. Furthermore, the results confirmed that the photocatalytic efficiency of ZnO was directly associated with the thickness and enlarged surface area of the layer. Finally, this study proved that the ZnO layers synthesised by electrolysis and heat treatment had shown better operational stability and reusability.

Textile/Al2O3–TiO2 nanocomposite as an antimicrobial and radical scavenger wound dressing

Improving the antimicrobial activity and radical scavenging ability of a textile-based nanocomposite is the key issue in developing a good and flexible wound dressing.

Second generation bioethanol potential from selected Malaysia's biodiversity biomasses: A review

Rising global temperature, worsening air quality and drastic declining of fossil fuel reserve are the inevitable phenomena from the disorganized energy management. Bioethanol is believed to clear out the effects as being an energy-derivable product sourced from renewable organic sources. Second generation bioethanol interests many researches from its unique source of inedible biomass, and this paper presents the potential of several selected biomasses from Malaysia case. As one of countries with rich biodiversity, Malaysia holds enormous potential in second generation bioethanol production from its various agricultural and forestry biomasses, which are the source of lignocellulosic and starch compounds. This paper reviews potentials of biomasses and potential ethanol yield from oil palm, paddy (rice), pineapple, banana and durian, as the common agricultural waste in the country but uncommon to be served as bioethanol feedstock, by calculating the theoretical conversion of cellulose, hemicellulose and starch components of the biomasses into bioethanol. Moreover, the potential of the biomasses as feedstock are discussed based on several reported works.

Zinc Oxide Nanoparticles-Immobilized Mesoporous Hollow Silica Spheres for Photodegradation of Sodium Dodecylbenzenesulfonate

ZnO-Immobilized mesoporous hollow silica spheres (ZnO/xMHSS; x = 15, 30, 50 molar ratio of Zn/Si) were synthesized and examined as photocatalysts toward the degradation of sodium dodecylbenzenesulfonate (SDBS). The hollow structures of MHSS and ZnO-immobilized MHSS composite were evidenced by transmission electron microscopy analysis. X-ray diffraction results confirmed the presence of ZnO and a mesoporous structure in the synthesized materials. N2 adsorption–desorption analysis also depicted the formation of a mesoporous structure and the increased surface area for the ZnO/xMHSS materials. Fourier transform infrared spectroscopy analysis revealed the formation of Si–O–Zn bonds due to interaction between ZnO and MHSS. The photocatalytic testing results indicated that all the ZnO/xMHSS materials showed improved efficiencies of 10–21 % toward the photodegradation of SDBS when compared with bare ZnO. Among the prepared materials, ZnO/15MHSS was the best photocatalyst, which photodegraded 68 % SDBS after 1 h reaction. The kinetic study demonstrated that the photocatalytic reaction followed the second-order model.

Novel oxidative-acidic bifunctional catalyst of tungsten-phosphate modified silica-titania

A novel oxidative-acidic bifunctional catalyst of silica-titania supported tungsten-phosphate was successfully synthesized and characterized. Different tungsten amount was impregnated into silica-titania followed by phosphoric acid treatment via sol gel method. The impregnation of WO3 and PO43- into TiO2-SiO2 followed by drying and calcination gave the white colour to the samples. X-ray diffractograms of the samples showed the structures of TiO2-SiO2 remained as amorphous structure after loading of WO3 and PO43-. The catalytic performance of the samples of PO43-/xW/TiO2-SiO2, (x = 1 and 5 wt %) as bifunctional catalyst in the formation of 1,2-octanediol through conversion of 1-octene to 1,2-epoxyoctane using aqueous H2O2 as an oxidant was evaluated. It has been demonstrated that PO43-/5W/TiO2-SiO2 was an active bifunctional oxidative-acidic catalyst in producing 1,2-octanediol from 1-octene. 

Synthesis and characterization of nitrogen-doped titania nanomaterials of homogeneous particle size

Modification of sol-gel method was used to synthesize homogeneous particle size nitrogen-doped titania (N-TiO2) nanomaterials using tetraethyl ammonium hydroxide (TEAOH) as N source. XRD analysis showed that these N-TiO2 (1-5 % N concentration) crystallined in anatase structure. The crystallinity of the samples decreased with increasing of N content. The calculation using Scherrer equation showed that the particle size of the synthesized N-TiO2 ranged 15.02 - 26.85 nm, strongly suggesting attainment of nanomaterials. DR UV-Vis results indicated that the band gap energy of 5% N doped TiO2 was only 2.58 eV, implying the sample could be a potential photocatalyst under visible light irradiation.  Homogeneous particle size of the synthesized nanomaterials was evidenced through FESEM images. Meanwhile, the EDX analysis confirmed the homogenous distribution of elements Ti, N and O in 5% N doped titania sample. 

Controlling the degradation kinetics of porous iron by poly(lactic-co-glycolic acid) infiltration for use as temporary medical implants

Iron and its alloy have been proposed as biodegradable metals for temporary medical implants. However, the formation of iron oxide and iron phosphate on their surface slows down their degradation kinetics in both in vitro and in vivo scenarios. This work presents new approach to tailor degradation behavior of iron by incorporating biodegradable polymers into the metal. Porous pure iron (PPI) was vacuum infiltrated by poly(lactic-co-glycolic acid) (PLGA) to form fully dense PLGA-infiltrated porous iron (PIPI) and dip coated into the PLGA to form partially dense PLGA-coated porous iron (PCPI). Results showed that compressive strength and toughness of the PIPI and PCPI were higher compared to PPI. A strong interfacial interaction was developed between the PLGA layer and the iron surface. Degradation rate of PIPI and PCPI was higher than that of PPI due to the effect of PLGA hydrolysis. The fast degradation of PIPI did not affect the viability of human fibroblast cells. Finally, this work discusses a degradation mechanism for PIPI and the effect of PLGA incorporation in accelerating the degradation of iron.

Sponged Structured Silica Containing Cobalt Oxide as Catalyst for Hydrolysis of Water Solution of Sodium Borohydride

Micro structured silica containing cobalt oxide materials was prepared by the calcination of silica containing cobalt salicylaldimine complexes. The SEM image showed that the prepared materials from higher content of cobalt salicylaldimine complexes had sponge-like structured. The IR and DR UV-Vis, spectra confirmed the presence of different species of cobalt oxide in materials originated from higher contain of the complex, which is attributed as Co3O4. The Co3O4 was believed as active species in catalytic hydrolysis of sodium borohydride. The catalytic testing also showed that the material originated from higher content of complex generated much higher hydrogen gas compare to the lower ones.

Effect of electric field in liquid phase oxidation of benzhydrol by aqueous hydrogen peroxide

Electric-field-induced oxidation of benzhydrol to benzophenone over conducting surface containing titanium dioxide has been carried out by usinghydrogen peroxide as oxidant. The results suggest the occurrence of synergistic effect of electric field and titania in which the interphase area between thetitania particles and conducting surface is the most active region for the reaction. The electrical field on the generation of surface charge to induce theadsorption of organic substrate has also been confirmed by dye adsorption experiments.

Gold Nanoparticles Embedded on the Surface of Polyvinyl Alcohol Layer

A novel method for synthesizing polyvinyl alcohol (PVA) embedded gold film is presented. Gold particles, in the size range of 20 to 180 nm, were first prepared by the conventional Turkevitch method by the reduction of gold, hydrogen  tetrachloroaurate (HAuCl4) with sodium citrate in water. The resulting gold nanoparticles were characterized by ultra violet-visible (UV-Vis) absorption spectroscopy, dark-field microscopy, transmission electron microscopy (TEM) and field emission electron microscopy (FESEM). In the preparation of PVA embedded gold film, PVA was functionalized with (3-mercaptopropyl) trimethoxysilane (MPTMS) which produced a thiol functionality on the surface. Then, gold particles were embedded on the surface of partially dried functionalized PVA where the gold particles are chemisorbed onto the thiol groups. Their physical properties were studied using Fourier transform infra red spectroscopy (FTIR), FESEM, TEM and UV-Vis diffuse reflectance (UV-Vis DR). Considering that the gold nanoparticles in solution cannot possibly be recovered and reused, the PVA embedded gold film on the other hand, has potential to be reused multiple of times.

Reactivity and Reusability of Mesoporous Alumina Nanoparticles Modified with Sulfuric Acid and Niobic Acid in the Alkylation of Resorcinol

With the development of large molecule hydrocarbon processes, mesoporous alumina which possesses high surface area with narrow pore size distribution has received a great deal of attention. However, its acid properties lack Bronsted acidity and showed only Lewis acid sites, making it an inactive solid catalyst in the alkylation of resorcinol, a reaction which requires the usage of solid acid catalysts with both Bronsted and Lewis acidity. In this study, in order to introduce Bronsted acidity to mesoporous alumina, sulfuric acid (H2SO4) and niobic acid (Nb2O5.nH2O) are introduced to the alumina. The reactivity of mesoporous alumina nanoparticles (MAN), Nb2O5.nH2O/MAN and H2SO4/MAN were tested out on the alkylation of resorcinol with methyl tert-butyl ether. No product was obtained using pure MAN, while both H2SO4/MAN and Nb2O5.nH2O/MAN managed to produce butylated resorcinol. Mesoporous alumina nanoparticles incorporated with sulfuric acid produced a greater amount of dibutylated resorcinol, which theoretically is a better antioxidant compared to monobutylated resorcinol. The reusability of the H2SO4/MAN catalyst was also better as dibutylated product was still obtained even in the second use. This indicates that sulfuric acid has created a more stable and also higher strength of Bronsted acidity in alumina as compared to niobic acid.