Effects of MgO Particle Loading on Gas Permeation Properties of Epoxidized Natural Rubber (ENR) / polyvinyl chloride (PVC) Membrane

A composite membrane was prepared by mixing epoxidized natural rubber (ENR) and polyvinyl chloride (PVC). An inorganic filler, MgO, was introduced into the polymer matrix by certain percentages to form a mixed matrix membrane (MMM). The resulting membranes were characterized using FTIR, TGA, SEM and gas permeability test. FTIR results showed the incorporation of MgO inside the membrane matrix with the appearance of an absorption peak at 3700 cm-1 which represents the formation of Mg(OH)2. Thermogram from TGA analysis showed two degradation stages at 250-350°C and 370-500°C, which correspond to the decomposition of PVC and ENR and the residue of fillers at 600°C. SEM images of the membranes showed that pores were developed as fillers were introduced to the membrane. The size of the pores also increased with the increase of filler percentage. As for gas permeation test, the permeability values of CO2 and N2 for ENR/PVC membrane were the lowest. The permeability values increased with the addition of MgO to the membrane. The permeability of CO2 was also the highest for all membranes

Epoxidized natural rubber/polyvinyl chloride/microcrystalline cellulose (ENR/PVC/MCC) composite membrane for palm oil mill effluent (POME) treatment

Epoxidized natural rubber/polyvinyl chloride/microcrystalline cellulose (ENR/PVC/MCC) composite membranes were prepared and used to treat palm oil mill effluent (POME). The loadings of MCC were varied at 0, 5, 10 and 15 w/w%. The increment of MCC loads has intensified the hydroxyl peak of the membranes in FTIR spectrum, indicating the increase in membrane hydrophilicity. MCC acted as a pore forming agent since the ENR/PVC/10% MCC gave the highest water flux and well-distributed pores. After first treatment of POME, the levels of chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solid (TSS) were reduced to 99.9%, 70.3%, and 16.9%, respectively. These data showed that ENR/PVC/MCC membrane has the potential to treat POME

Cellulose-based hydrogel as halal agricultural medium

Waste paper has been thrown away and caused environmentally problem. Preparation of cellulose-based hydrogel from waste paper has been developed to decrease the pollution since waste paper contains more than 60% of cellulose. Cellulose-based hydrogel is produced from the waste paper solution. To make into hydrogel, the addition of crosslinking agent is needed since hydrogel is defined as a 3D network structure that is crosslinked either chemically or physically. In this study, the waste paper will be treated first to remove impurities. Sodium hydroxide/urea (NaOH/Urea) has been used as a solvent for waste paper dissolution. As hydrogel needed crosslinking to remain the network structure, we used citric acid (CA) as a chemical crosslinking agent and the heating at 60°C and 70°C before and after swelling was studied. The aim of this study is to produce halal soilless agricultural medium using cellulose-based hydrogel media from the waste paper by using non-toxic and environmental friendly solvents and CA as crosslinking agent. Waste paper hydrogel will be characterized via swelling ratio where the highest swelling is about 19% at 70°C heating temperature. Fourier-transform infrared (FTIR) shows a broad band of OH at 3339 cm-1 and another band was shown at 3432 cm-1 for 70°C heating temperature represent OH from the solvent

Ciri fizikokimia filem boleh makan dan filem polietilena bagi ubi keledek (Ipomoea batatas) goreng

Penyelidikan dijalankan bagi menilai kesan penggunaan filem boleh makan dan filem polietilena (PE) sebagai bahan penyalut untuk ubi keledek (Ipomoea batatas) goreng. Kepingan ubi keledek disalut dengan lapisan filem boleh makan yang terdiri daripada 0.045 g/mL selulosa metil (MC), 0.045 g/mL selulosa hidroksipropil metil (HPMC) dan 0.16 g/mL jagung zein (CZ) sebelum digoreng di dalam minyak sawit pada suhu 170-180°C selama 3 min. Manakala ubi keledek juga disalut dengan filem tak boleh makan iaitu polietilena (PE) (nisbah PE kepada minyak 1:100 g/g) sebagai perbandingan. Ubi goreng tanpa salutan filem digunakan sebagai sampel kawalan. Ciri fizikokimia ubi goreng bersalut dianalisa. Keputusan menunjukkan semua filem melekat pada permukaan ubi setelah digoreng. Penggunaan filem CZ menjadikan permukaan filem licin dan wujud tanpa sebarang retakan. Filem MC pula memberi lapisan permukaan yang tidak rata tetapi menyaluti permukaan sampel dengan sekata. Tambahan pula, ubi bersalut MC menunjukkan peratusan lemak paling sedikit (13.6%) selain kandungan kelembapan yang paling tinggi (17.5%) berbanding sampel lain. Secara keseluruhan, MC merupakan filem yang terbaik untuk mengekalkan kelembapan bahan goreng dan mengurangkan penyerapan lemak

The effect of molecular weight on the surface and permeation of poly(L-lactic acid)-poly(ethylene glycol) membrane with activated carbon filler

The use of biodegradable material in membrane technology will be a great solution in reducing non-biodegradable waste in the landfill. Membranes can often be useful as the recycle stream can usually be much cleaner than with other techniques. This article describes the preparation of poly(l-lactic acid)-poly(ethylene glycol) (PLLA-PEG) free standing flat sheet membranes with the presence of 5 wt. % activated carbon filler. PLLA-PEG crosslinked copolymer was synthesized using PLLA with different molecular weight PEG prepolymers i.e. 4000, 6000 and 10000 g/mol; and excess hexamethylene diisocyanate to form urethane linkages between the polymers. The reaction was carried out in a dichloromethane/tetrahydrofuran dual-solvents system. The PLLA-PEG/AC membranes in the weight ratio of 7:3:0.5 were then fabricated using solution casting and phase inversion techniques. The performance of the membranes was evaluated in terms of permeation water flux (PWF), palm oil mill effluent (POME) permeation, flux decline and contact angle. It was found that membrane containing 10000 g/mol PEG has the highest total mean in PWF, POME flux and hydraulic permeability with values of 100.9 L/m2.h, 51.45 L/m2.h and 64.9º;62.9º, respectively, due to high porosity. All of the membranes were more stable towards the flux decline of POME compared to water. At the same time, addition of AC to the copolymer considerably enhances the texture and porosity of the fabricated membranes

Empty fruit bunch cellulose based sorbent for oil sorption in palm oil mill effluent

The aim of this study was to develope hydrophobic biodegradable cellulosic sorbent materials from empty fruit bunch (EFB) for oil sorption in palm oil mill effluent (POME). EFB cellulose was modified using acetic anhydride (AA) and the effect of ratio of EFB cellulose mass to AA volume (1:20, 1:30, 1:40, 1:50 g/mL) at 3 h reaction time with 5% (w/v) pyridine catalyst. The acetylation process was quantitatively determined using the weight percent gain (WPG) and modified EFB cellulose (1:40) showed the highest WPG (13.0%) compared to the other ratios. Fourier Transform Infrared (FTIR) spectrum shows that after the modification, the intensity of –OH peak at 3329 cm-1 decreased and the new peak at 1728 cm-1 of C=O ester emerged. This implied that acetylation process was successful when AA volume increased except for 1:50 ratio. Sample 1:40 also showed good hydrophobicity characteristic with the degree of hydrophobicity (DH) of 87.7%. X-ray diffraction (XRD) analysis shows that crystallinity index for 1:40 is the lowest which indicated that the sample become amorphous due to acetylation. The result is in agreement with scanning electron microscope (SEM) micrograph that shows the surface morphogy of EFB cellulose after the modification became rougher. Moreover, the modified EFB cellulose 1:40 was able to absorb oil from POME up to 98.5%. Thus, it is proven that cellulose from EFB can be modified to a certain ratio to make it an extremely promising natural source oil sorbent in treating POME

Chemistry Outreach Program and its Impact on Secondary School Students

AbstractChemistry is one of the most difficult subjects and usually feared by the students in elementary schools. Some of the students in Malaysia, especially in the rural area, they memorized experiments and the theories without really understand the beauty of chemistry. They also believed that the chemistry experiment can only be done in the laboratory equipped with a huge fume hood since all of the experiments are dangerous, explosive and costly. Chemistry outreach program held by a team from Universiti Kebangsaan Malaysia was meant to change the perspective of the elementary students towards chemistry and to develop their interest in exploring the beauty of chemistry. The program took place in Perlis as part of the Science on Wheels Program organized by National Science Centre. Few experiments using chemicals which can be found in daily life were first demonstrated and explained. Then the students were given chances to try on their own. They were also asked to relate what they had learned from the experiments to the phenomenon that occurred in the world. Survey on knowing their interest in chemistry before and after the experiments was given and analyzed. The results showed that the level of liking chemistry and choosing chemistry as one of the career option depended mainly on the exposure towards chemistry. The result showed that 80% of the students were interested in chemistry after they performed the experiments compared to 72% who were interested in the chemistry subject taught in school prior to the experiment. The 8% increment was possibly a reflection of the effective learning through experiment. Overall, 58% of students were interested to choose chemistry as their future career and suprisingly it was not depended on the background of the family. The chemistry outreach program really gave the impact on the elementary students and reached their hearts and should be continued from time to time to attract students to science and technology

Treatment of palm oil mill effluent by poly(L-lactic acid)-poly(ethylene glycol)/silica membrane

Biodegradable membrane technology has received an increasing interest in many fields of applications exclusively to preserve the earth. A renewable polymer such as poly(L-lactic acid) (PLLA) often being introduced with reinforcement material to improve the characteristics of membranes itself. Herein, this study highlights the development of membrane from poly(L-lactic acid)-poly(ethylene glycol) (PLLA-PEG) copolymer with silica (SiO2 ) in the treatment of palm oil mill effluent (POME) wastewater. We hypothesized that the incorporation of SiO2 as a nanofiller promoted PLLA-PEG/ SiO2 membrane to have a porous and higher number of pores on the membrane surface. Therefore, the effect of silica amount added in the PLLA-PEG copolymer membrane was also investigated and examined by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Based on FTIR analysis, the presence of the urethane (-NHCOO-) functional group indicated the formation of PLLAPEG copolymer and SEM micrographs showed porous surface on the membranes with increasing pores size in a favor of SiO2 amount added. Also, the surface wettability of membranes was evaluated through water contact angle which render hydrophilic characteristics. These membranes were subsequently applied for POME filtration where the test resulted in significant discolouration of POME. Furthermore, the high percentage removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solid (TSS) up to 99.5% empowers the treated POME wastewater to be within the range set by the Malaysian Department of the Environment

Haid daripada perspektif sains dan maqasid syariah

Setiap kejadian semula jadi merupakan rahmat dan memberi kemaslahatan kepada manusia termasuklah pendarahan haid dalam kalangan wanita. Haid merupakan suatu proses yang unik dan terancang yang melibatkan tiga fasa utama iaitu fasa haid, fasa folikel dan fasa luteal. Objektif penyelidikan ini ialah untuk mengkaji dan menghubungkaitkan kebaikan haid daripada perspektif sains dan maqasid syariah. Kajian ini dijalankan dengan menggunakan ulasan literatur secara deskriptif. Kajian mendapati bahawa perubahan hormon, warna darah dan faktor fiziokimia lain memberi kesan terhadap kenormalan kitaran haid. Darah haid juga dikenal pasti mempunyai agen antimikrob terutamanya terhadap bakteria E. coli dan bakteria Gram-negatif lain. Hal ini bertepatan dengan maqasid syariah memelihara jiwa kerana haid mampu juga memelihara kesihatan wanita. Selain itu, kajian lepas menemukan bahawa darah haid terdiri daripada sel stem yang boleh digunakan dalam aktiviti klinikal pada masa akan datang. Maqasid syariah melindungi keturunan juga dapat dilihat dengan kehadiran haid yang sering digunakan bagi menjangkakan waktu subur bagi merancang kehamilan. Hikmah Islam melarang mendekatkan diri (bersetubuh) dengan wanita yang sedang haid adalah satu rahmat yang besar, kerana wanita yang sedang haid biasanya mempunyai kelaziman gejala prahaid (PMS) yang melibatkan isu kesihatan. Oleh itu, haid daripada perspektif sains adalah bertepatan dengan maqasid syariah

Cellulose powder from Piper nigrum L. agro-industrial waste: effect of preparation condition on chemical structure and thermal degradation

White pepper is generally produced via water retting process to decorticate the pericarp of green pepper. The decorticated pericarp is considered as an agro-industrial waste and environmental pollutant as many farmers still discard the waste into the rivers. These wastes majorly contain cellulose, hemicellulose, pectin, and other organic compound. Cellulose was obtained from alkaline treatment (4 wt. % sodium hydroxides, NaOH) followed by bleaching process. This study reports the effect of soaking cycle in bleaching treatment on the chemical structure and thermal degradation of cellulose. The cellulose obtained from pepper (Piper nigrum L.) pericarp waste were characterised by colour analysis, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Increased number of bleaching cycles produced a whiter colour and high thermal stability of cellulose powder. The whiteness index (WI) for high bleaching cycle sample was found significantly high (p<0.05) with the value of 77.00 ± 1.10. Thermal analysis indicates a derivative thermogravimetric analysis (DTG) peak at 332 °C. The FTIR spectrum proven that the condition of bleaching treatment changes the absorption intensity at bands 1732, 1540, and 1460 cm-1 which due to the loss of hemicellulose and lignin. The use of pepper pericarp waste that is usually discarded may provide a sustainable alternative for the production of cellulose