Kajian terhadap hidrogel berasaskan selulosa bakteria (BC) dan kesan penggabungannya dengan nanopartikel perak sebagai agen antibakteria

This research investigated the ability of bacterial cellulose (BC) based hydrogel incorporated with silver nanoparticles as antibacterial agent. Free radical polymerization has been used to synthesize the BC hydrogel. The silver nanoparticles was integrated and reduced using sodium boron hydrate as the reducing agent. The swelling capability of the hydrogel at different pH was also examined. The FTIR results showed that acrylic acid (AA) was successfully grafted to the bacterial cellulose networks. Other analyses such as swelling tests, antibacterial, Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were also carried out to the hydrogel sample. The antibacterial tests found that hydrogel incorporated with silver nanoparticles was able to inhibit the bacterial growth

Sintesis dan sifat termal natrium kanji sulfat Dioscorea pentaphylla

Kanji Dioscorea pentaphylla telah diubah suai dengan pensulfatan dan peneutralan bagi menghasilkan natrium kanji sulfat. Tindak balas pensulfatan dilakukan dengan asid sulfurik dalam etanol dan air pada suhu 0oC. Darjah penukargantian dikira berdasarkan peratus karbon dan sulfur yang ditentukan menggunakan penganalisis unsur CHNS. Natrium kanji sulfat yang mempunyai darjah penukargantian dan peratus nisbah berat hasil yang tinggi dipilih dan dicirikan dengan spektrum transformasi Fourier inframerah (FT-IR) dan profil pembelauan sinar-X (XRD). Kehadiran dua puncak getaran regangan C-O-S dan S=O dalam spektrum FT-IR dan puncak berbeza yang terhasil dalam corak difraktogram XRD membuktikan tindak balas berlaku pada struktur kanji. Sifat termal juga ditentukan dengan kalorimeter pengimbas pembezaan (DSC) dan analisis termogravimetri (TGA). Natrium kanji sulfat yang dihasilkan mempunyai kestabilan termal yang baik kerana mempunyai suhu penguraian pada 265oC. Natrium kanji sulfat ini sesuai dijadikan bahan tambahan dalam penghasilan hidrogel, organogel dan filem dengan sifat anionik kerana degradasi tidak terjadi di bawah suhu ini

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

A Study on Microgel System as a Template for Dispersion and Separation of Chiral Tartaric Acid

Separation of tartaric acid enantiomers in organic compounds using conventional techniques requires high energy demand, high chemicals consumption, lengthy, complicated and expensive processes. This research demonstrates utilization of PNIPAM microgel system as a template for incorporation of chiral D- and L- tartaric acids (TA). The poly(n-isopropylacrylamide) (PNIPAM) microgel was synthesized using surfactant free emulsion polymerization (SFEP) and was characterized using standard procedures. The combination of 1.4×10-3 g/ml microgel with 3.02×10-4 g/ml TA gave the most stable system. Subsequently, a two-phase system was obtained after centrifugation. Both phases were subjected to dynamic light scattering (DLS) analysis and the corresponding separated systems gave particle sizes ranging from 80-90 nm for the upper phase, and 1200-1500 nm for the lower phase. Scanning electron micrographs showed the presence of agglomeration in the lower phase, supporting the DLS results. Nuclear magnetic resonance (1H NMR) analysis confirmed the presence of TA indicated by a peak at δ = 13.1 ppm. Based on these findings, the system can be a potential alternative template for TA racemix acid dispersion and separation

The effect of temperature on the dispersion of α-Mangostin in PNIPAM microgel system / Madihah Ahmad, Bohari M. Yamin and Azwan Mat Lazim

α-Mangostin was extracted from the pericarp of the Malaysian local Garcinia mangostana linn., The structure was characterised by Infrared red, UV-Visible and Nuclear Magnetic Resonance spectroscopic data. The fluorescence peak at 500nm in ethanol was not observed in PNIPAM microgel solution. The increase of colloidal size of the gel in the presence of α-mangostin was studied by Dynamic Light Scattering and Transmission Electron Microscope. The size of the particle also increases with increasing temperature up to 45⁰C after which it began to shrink. The TEM micrograph at 45°C showed a uniformly structured pattern of the gel occurs in the range of the lowest solution critical temperatur

The optimization of heating temperature for carbon extraction from peat soil

This study aims to find the optimised heating temperature for carbon extraction from peat soil. Ccarbon from peat soil was extracted by the pyrolisation process at temperature, T = 200, 300, 400, 500, 600 and 700°C for 5 hours. The carbon, C and silica, Si content extracted from peat soil at various heating temperatures were measured by using an Energy Dispersive X-Ray analyzer (EDX) at 3 points on the sample surface. High atomic percentage of carbon (95.44 %) was measured at T = 400°C, while the highest atomic percentage of silicon was recorded at T = 700°C (30.79 %). The surface morphology of peat soil was analysed using Scanning Electron Microscope (SEM) at 800 magnifying power, and it was clearly seen that peat fragments were pyrolised at high heating temperature with pores enhancement. The molecular structure parameter of the extracted carbon were identified using Laser Raman analysis. The peak positions of D-band and G-band for raw peat soil were observed at Raman shift of 1379.62 and 1549.02 cm-1, respectively. Meanwhile, the D-band for peat soil heated at temperature of 400°C was 1391.56 cm-1 whereas the G-band has peak position at 1562.16 cm-1 . From the Raman spectra of the optimum heating temperature at 400°C, it was revealed that the carbon molecular structure from the peat soil is mainly attributed by graphite and diamond structure

Kebolehserapan metilena biru oleh hidrogel selulosa bakteria teradiasi gamma menggunakan isoterma langmuir dan freundlich

Kajian ini bertujuan menghasilkan hidrogel responsif berasaskan selulosa bakteria yang diperoleh daripada Nata de Coco (NDC) dan asid akrilik (AA). Tiga jenis sampel telah disediakan berdasarkan nisbah NDC:AA iaitu sampel hidrogel A [1:1], B [2:1] dan C [3:1]. Pencangkukan AA terhadap molekul NDC menggunakan kaedah pempolimeran radikal Gamma (GRP) menghasilkan hidrogel NDC-AA (sumber: 60Co). Kaedah yang menggunakan tenaga yang tinggi ini akan menghasilkan radikal bebas seperti OH•, H•, H2O2 dan H2. Kesemua radikal ini menyerang kumpulan berfungsi yang terdapat pada NDC dan AA seterusnya menggalakkan proses pencangkukan AA terhadap NDC. Hidrogel B [2:1] dipilih dan diuji sebagai penjerap metilena biru (MB) dan perubahan keamatannya telah dianalisis menggunakan spektrofotometer UV-VIS. Keputusan yang diperoleh telah diselaraskan dengan dua model isoterma, Langmuir dan Freundlich. Perbandingan pemalar bagi kedua-dua model isoterma ini mendapati hidrogel B [2:1] yang dihasilkan telah mematuhi kedua-dua model isoterma. Keputusan yang diperoleh ini menyokong keupayaan hidrogel B [2:1] untuk digunakan sebagai penjerap alternatif MB yang paling efisien

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

Penghasilan zarah nano ferum oksida (FeNPs) daripada garam ferosenium menggunakan hidrogel poli-akril amida (P(Am) sebagai templat

Kajian ini adalah bertujuan mengkaji potensi hidrogel sebagai templat nanoreaktor bagi menghasilkan zarah nano ferum oksida (FeNps). Hidrogel Poli-AkrilAmida (PAAm) telah dihasilkan dengan menggunakan kaedah pempolimeran radikal bebas. Keupayaan penyerapan air dalam hidrogel telah diuji dan nisbah pembengkakan tertinggi telah berlaku pada larutan penimbal pH10. Hidrogel yang terhasil telah dicirikan dengan menggunakan pengimbas mikroskop elektron (SEM) diikuti dengan spektroskopi serakan tenaga X-ray (SEM-EDEX) untuk menentukan jumlah peratusan ferum (Fe). Selepas proses pengkalsinan, zarah nano diekstrak daripada hidrogel PAAm dan seterusnya dianalisis menggunakan mikroskop transmisi elektron (TEM) dan analisis pembelauan sinar-X (XRD). Hasil TEM telah menunjukkan bahawa saiz zarah yang dihasilkan adalah antara 5 - 20 nm. Analisis XRD pula mengesahkan kehadiran zarah ferum oksida (Fe2O3). Keputusan ini menunjukkan bahawa hidrogel berpotensi digunakan sebagai nanoreaktor bagi menghasilkan zarah nano

A Preliminary Study on Gum Arabic as a Binder in Preparation of Starch Based Edible Plastic

This research emphasizes on synthesizing edible plastic using a one pot method by adding starch, gum Arabic as theb binder and sugar (sorbitol and glycerol). In order to get the right composition, the ratio of each ingredient was varied. The FTIR spectroscopy was used to characterize the structure and composition of the sample produced