Eaqub Ali

Statistical Optimization for Acid Hydrolysis of Microcrystalline Cellulose and Its Physiochemical Characterization by Using Metal Ion Catalyst

Hydrolyzing the amorphous region while keeping the crystalline region unaltered is the key technology for producing nanocellulose. This study investigated if the dissolution properties of the amorphous region of microcrystalline cellulose can be enhanced in the presence of Fe3+ salt in acidic medium. The process parameters, including temperature, time and the concentration of metal chloride catalyst (FeCl3), were optimized by using the response surface methodology (RSM). The experimental observation demonstrated that temperature and time play vital roles in hydrolyzing the amorphous sections of cellulose. This would yield hydrocellulose with higher crystallinity. The factors that were varied for the production of hydrocellulose were the temperature (x1), time (x2) and FeCl3 catalyst concentration (x3). Responses were measured in terms of percentage of crystallinity (y1) and the yield (y2) of the prepared hydrocellulose. Relevant mathematical models were developed. Analysis of variance (ANOVA) was carried out to obtain the most significant factors influencing the responses of the percentage of crystallinity and yield. Under optimum conditions, the percentage of crystallinity and yield were 83.46% and 86.98% respectively, at 90.95 °C, 6 h, with a catalyst concentration of 1 M. The physiochemical characteristics of the prepared hydrocellulose were determined in terms of XRD, SEM, TGA and FTIR analyses. The addition of FeCl3 salt in acid hydrolyzing medium is a novel technique for substantially increasing crystallinity with a significant morphological change.

Impact of hydrogen concentrations on the impedance spectroscopic behavior of Pd-sensitized ZnO nanorods

ZnO nanorods were synthesized using a low-cost sol-gel spin coating technique. The synthesized nanorods were consisted of hexagonal phase having c-axis orientation. SEM images reflected perpendicular ZnO nanorods forming bridging network in some areas. The impact of different hydrogen concentrations on the Pd-sensitized ZnO nanorods was investigated using an impedance spectroscopy (IS). The grain boundary resistance (Rgb) significantly contributed to the sensing properties of hydrogen gas. The boundary resistance was decreased from 11.95 to 3.765 kΩ when the hydrogen concentration was increased from 40 to 360 ppm. IS gain curve showed a gain of 6.5 for 360 ppm of hydrogen at room temperature. Nyquist plot showed reduction in real part of impedance at low frequencies on exposure to different concentrations of hydrogen. Circuit equivalency was investigated by placing capacitors and resistors to identify the conduction mechanism according to complex impedance Nyquist plot. Variations in nanorod resistance and capacitance in response to the introduction of various concentrations of hydrogen gas were obtained from the alternating current impedance spectra.

Modification of gelatin–DNA interaction for optimised DNA extraction from gelatin and gelatin capsule

BACKGROUND Poor quality and quantity of DNA extracted from gelatin and gelatin capsules often causes failure in the determination of animal species using PCR. Gelatin, which is mainly derived from porcine and bovine, has been a matter of concern among customers in order to fulfill religious obligation and safety precaution against several transmissible infectious diseases associated with bovine species. Thus, optimised DNA extraction from gelatin is very important for successful real-time PCR detection of gelatin species. In this work, the DNA extraction method was optimised in terms of lysis incubation period and inclusion of pre-treatment pH modification of samples. RESULTS The yield of DNA extracted from porcine gelatin was significantly increased when the pH of the samples was adjusted to pH 8.5 prior to DNA precipitation with isopropanol. The optimal pH for DNA precipitation from bovine gelatin solution was then determined at the original pH range of solution: pH 7.6 to 8. A DNA fragment of approximately 300 base pairs was available for PCR amplification. CONCLUSION DNA extracted from gelatin and commercially available capsules has been successfully utilised for species detection using real-time PCR assay. However, significant adulterations of porcine and bovine in pure gelatin and capsules have been detected, which require further analytical techniques for validation.

Multifunctional Carbon Nanotubes (CNTs): A New Dimension in Environmental Remediation

Water pollution is a serious, persistent and emerging problem not only in Malaysia but all over the world. It has negative impacts on the sustainability of water resources, aquatic flora and fauna and community health. It significantly reduces total water availability because of the lack of suitable and cost-effective pollutant treatment facilities. Current facilities for water purification are time consuming, expensive and have low affinity and efficiency to newly emerging micro pollutants in water. Carbon nanotube (CNT) based nanocomposites and hybrids have attracted huge attention for their potential in the treatment of newly emerging micropollutants in water bodies. Addition of various molecules and binders such as magnetic nanoparticles, pollutant binding and degrading receptors and enzymes has added new dimensions in the fibrous shape, high aspect ratio, large surfaces, and accessible mesopores of CNTs. In this review, we have outlined the recent progress and future prospects of multifunctional CNT-hybrids for the treatment of both conventional priority and newly emerging micropollutants in water environment. The review also has highlighted the future strategies for overcoming the shortcomings of existing techniques and materials for water purification applications.

Nanoclustered Gold: A Promising Green Catalysts for the Oxidation of Alkyl Substituted Benzenes

Catalytic oxidation of alkyl substituted benzenes is an essential route for the synthesis of a number of important chemicals, perfumes, drugs and pharmaceuticals. The oxidation products of ethyl benzene are important precursors for a wide range of pharmaceuticals and synthetic materials. Acetophenone and 1-phenylethanol are two oxidation products of ethyl benzene which are the precursors of optically active alcohol, benzalacetophanones, hydrazones and so on. However, the oxidations of alkyl substituted benzenes have been remaining a challenging task. This is because of the limitations of an appropriate catalyst and requirement of corrosive chemical treatments (potassium permanganate/dichromate and ammonium cerium nitrate) which are hazardous and environmentally unfriendly. The current industrial practice in the oxidation of ethyl benzene unfortunately involves high temperature thermal autoxidation in the absence of catalysts. Although few catalysts have been tested for the oxidation of ethyl benzene, many of them found to be inefficient. For example, cobalt (II) oxide-immobilized on mesoporous silica (Co/SBA-15) was used to catalyze oxidation of alkyl benzene at high temperature (125-150°C) but only 70% conversion was obtained after prolong treatment at 150°C. Additionally, the catalyst formed mixed uncontrolled oxidation products like 1-phenylethyl hydro peroxide, benzoic acid, acetophenone and phenyl ethanol. Carbon/silica/metal oxide supported nanoporous gold is a promising green catalyst for heterogenous molecular transformation. This is because of their three dimensional open pore network structures, high surface to volume ratio, high reusability, distinct optolectronic and physio-chemical properties. Mesoporous carbon/silica/metal oxide thin film supports provide increase dispersion of metal nanocatalysts and facilitate transport of molecules, ions or electrons through the nanopores/nanochannels, enhancing product yields with minimum cost and time. This paper has reviewed various gold-skeleton green catalysts and their preparation and mechanistic schemes for the selective oxidation of alkyl substituted benzenes.

Duplex real-time PCR assay using SYBR Green to detect and quantify Malayan box turtle (Cuora amboinensis) materials in meatballs, burgers, frankfurters and traditional Chinese herbal jelly powder

ABSTRACT The Malayan box turtle (Cuora amboinensis) (MBT) is a vulnerable and protected species widely used in exotic foods and traditional medicines. Currently available polymerase chain reaction (PCR) assays to identify MBT lack automation and involve long targets which break down in processed or denatured tissue. This SYBR Green duplex real-time PCR assay has addressed this research gap for the first time through the combination of 120- and 141-bp targets from MBT and eukaryotes for the quantitative detection of MBT DNA in food chain and herbal medicinal preparations. This authentication ensures better security through automation, internal control and short targets that were stable under the processing treatments of foods and medicines. A melting curve clearly demonstrated two peaks at 74.63 ± 0.22 and 78.40 ± 0.31°C for the MBT and eukaryotic products, respectively, under pure, admixed and commercial food matrices. Analysis of 125 reference samples reflected a target recovery of 93.25–153.00%, PCR efficiency of 99–100% and limit of detection of 0.001% under various matrices. The quantification limits were 0.00001, 0.00170 ± 0.00012, 0.00228 ± 0.00029, 0.00198 ± 0.00036 and 0.00191 ± 0.00043 ng DNA for the pure meat, binary mixtures, meatball, burger and frankfurter products, respectively. The assay was used to screen 100 commercial samples of traditional Chinese herbal jelly powder from eight different brands; 22% of them were found to be MBT-positive (5.37 ± 0.50–7.00 ± 0.34% w/w), which was reflected through the Ct values (26.37 ± 0.32–28.90 ± 0.42) and melting curves (74.63–78.65 ± 0.22°C) of the amplified MBT target (120 bp), confirming the speculation that MBT materials are widely used in Chinese herbal desserts, exotic dishes consumed with the hope of prolonging life and youth.

Conventional to Nano-Green Adsorbents for Water Pollution Management - A Review

Pure and clean water is a must for living a healthy life. However, the increasing influence of urbanization, industrialization, domestic and agricultural activities, is continuously adding both conventional and newly emerging pollutants to the earths water bodies, seriously affecting both the terrestrial and aquatic flora and fauna. Thus water pollution has become a major issue in the global perspectives. In the last few decades, numerous methods, such as chemical precipitation, filtration, oxidation, ion exchange treatment and adsorption have been proposed for the purification of contaminated water. Among these methods, adsorption has taken an important position in water purification technology. This is because of its ease of operations, cost-effective maintenance, and availability of adsorbents in various forms with high surface area, porous structure and specific surface reactivity. Instead of having many attractive properties, many adsorbents have failed to achieve a good acceptability at commercial levels. In the recent years, nanotechnology approaches have introduced nanoadsorbent which is capable of removing water pollutants more efficiently. In this review, various water treatment techniques with their shortcomings followed by efficiency of adsorption and nanoadsorbent for pollutant removal are discussed with green chemistry perspectives.

Zeolite Supported Ionic Liquid Catalyst for the Synthesis of Nano-Cellulose from Palm Tree Biomass

Nanocellulose promises to be a very versatile material having wide range of biomedical and biotechnological applications including tissue engineering, drug delivery, wound dressings, medical implants, food, cosmetics, paper and textiles. The current methods for the synthesis of nanocellulose involve harsh chemical treatments which are perpetually hazardous to human and environment. Catalytic synthesis of nanocellulose might be a green approach. Among the various types of catalyst, ionic liquids, which are composed of both cations and anions and have low or negligible vapor pressure, are particularly promising. Ionic liquids also exhibit a relatively wide electrochemically stable window, good electrical conductivity, high ionic mobility, a broad range of room temperature liquid compositions, selective dissolvability to many organic and inorganic materials, and excellent chemical and thermal stabilities. In contrast, zeolite catalysts have been used in petroleum refineries for the removal of sulfur. Zeolite catalysts are also important for the synthesis of bulk chemicals, fine and specialty chemicals, fuels and chemicals. Acidic and metal modified micro porous zeolite catalysts have been used in several commercial processes in petroleum industry, fuel components, abatement of exhaust gas emissions and biomass upgrading, pharmaceutical and fine chemical industries. Currently, zeolite catalysts are synthesized in powder form and to make them industrially useful, such catalysts have to be mixed with a binder and formulated in different shapes. This paper reviewed the introduction, preparation, synthesis and application of nanocellulose from lignocellulosic palm biomass.

Green Catalytic Approach for the Synthesis of Platform Chemicals from Palm Tree Lignin

Lignin is the second most abundant naturally occurring macromolecule found in plant cell-wall, vascular components and woody stems. It is the largest renewable source of aromatic biopolymer. However, lignin is recalcitrant to be broken down by most chemicals. This is because of its complicated heterogeneous molecular structure. However, lignin depolymerization has huge potentials for the synthesis of a number of useful chemicals, perfumes and pharmaceuticals and toiletries. The oxidation products of lignin are important precursors for pulp/paper and food industries, synthetic thin films. Vanillin, veratryl aldehyde and para-benzoquinone are the oxidation products of lignin. These chemicals are the precursors of optically active alcohol, ketone, violuric acid and benzaldehyde. However, the oxidation of biolignin has been remaining a challenging task. Green catalytic approaches might be an interesting solution for the selective depolymerization of lignin into various platform chemicals. Metal oxide/silica supported nanoporous gold has received strong attention as green catalyst for the transformation of various natural polymers. Mesoporous metal oxide/silica provide enlarged surfaces for the breakdown of C-C, C-H and C-OH bonds. This paper has reviewed various green catalytic approaches for the control depolymerization of biolignin into platform chemicals.

Photoconductive Carbon Nanotube (CNT): A Potential Candidate for Future Renewable Energy

Human population has always been advocated to use exosomatic energy, exist in abundance in Mother Nature. As of today worlds population has reached to 7.1 billion, which will be exceeding 8.0 billion by 2050. To fulfill the energy demand of increasing population, world existing energy should be increased by >50% by 2050. The question is do we have enough energy resources to meet the future energy demand Secondly, the use of reserved gas, oil, coal and other carbon-based energy sources would continue to emitgreenhouse gases which are estimated to warm up the world by 2°C by 2020, raising the sea level which will dwindle the world cultivable land. This paradigm shift has called foreffective, sensitive and advanced technologies dealing with the production, harvesting, conversion and distribution of renewable energy to meet the future energy needs. This paper has highlighted the potential applications of carbon nanotube (CNT) based composites to harvest the unlimited solar energy into electrical, mechanical and other forms of useful energy for human benefits. The competitive performances of CNTs in solar cells would build multibillion dollar energy market using green chemistry principles, reducing green house emission and ensuring enough energy for the future generations.