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ANTIOXIDANT ACTIVITY, SKIN IRRITAION POTENTIAL AND CHEMICAL COMPOSITION OF CLOVE LEAF OIL FROM WEST JAVA INDONESIA
Get PDFANTIOXIDANT ACTIVITY, SKIN IRRITATON POTENTIAL, AND CHEMICAL COMPOSITION OF CLOVE LEAF OIL FROM WEST JAVA INDONESIA. Essential oils with specific chemical compositions have the potential as a source of antioxidants in cosmetics, however, in general, essential oils are not safe because of the potential for skin irritation. This study aims is to perform fractionation to obtain clove oil with a chemical composition that is safe on the skin and does not reduce its antioxidant activity. Fractionation was performed at a temperature of 100 – 285 oC. Chemical composition was determined by Mass Chromatography Spectrometry (GC-MS), antioxidant activity by DPPH method, and irritation potential by in-vivo patch test. The results showed chemical components of clove oil were eugenol, copaene, beta caryophyllene, iso-eugenol, alpha caryophyllene, cadinene, caryophyllene oxide, caryophylla and beta caryophylla. Fractions with chemical compositions of eugenol and beta caryophyllene as the main components and copaene, iso-eugenol, alpha caryophyllene, cadinene as secondary components have very light erythema and no potential irritation to the skin. The fraction produced from the fractionation of crude clove oil at a temperature of 235 – 260 oC has the highest antioxidant activity of 10.17 mg/L
SODIUM LAURETH SULFATE (SLS) DECORATED α-PbO NANOCRYSTALS: OPTICAL, STRUCTURE, AND MORPHOLOGY, PROPERTIES
Get PDFSODIUM LAURETH SULFATE (SLS) DECORATED α-PbO NANOCRYSTALS: OPTICAL, STRUCTURE, AND MORPHOLOGY PROPERTIES. The α-PbO nanocrystals were successfully decorated using sodium laureth sulfate (SLS) anionic surfactant. The method used is one-pot synthesis approach. The precursor used is lead nitrate (Pb(NO3)2). The UV-Vis spectrophotometer showed the absorption peak of α-PbO nanocrystals was seen at wavelength of 237 nm and an absorbance value of 0.7. The optical properties of PbO nanocrystals can be seen at the bandgap value of 4.2 eV. FT-IR spectroscopy showed the shift of absorption peak at the wavenumber of 1358 cm-1. XRD spectroscopy showed the crystals of PbO at diffraction angles (2θ) of 10-80o: 29.17, 32.54, 37.85, 39.62, 45.16, 46.21, 56.12, and 61.73 with miller indices of (111), (200), (201), (121), (220), (030), (311), and (032), respectively. The crystal size average of PbO was 56.32 nm. The results of PSA and PZC shows the particle size distribution of PbO is 71.5 nm with inter-particle charge of -25 mV. SEM-EDX data shows the PbO nanocrystals have an irregularly spherical with a compounds composition of Pb (83.12%) and O (16.88%). From the data of characterization, it can be concluded the PbO nanocrystals was successfully decorated using the surfactant anionic of sodium laureth sulfate
PICKERING EMULSION TECHNOLOGY IN FABRICATE CELLULOSE FOAM FROM OIL PALM EMPTY FRUIT BUNCH WASTE
Get PDFPICKERING EMULSION TECHNOLOGY IN FABRICATE CELLULOSE FOAM FROM OILPALM EMPTY FRUIT BUNCH WASTE. Cellulose from the oil palm empty fruit bunch (OPEFB) waste can make a porous material. This study aims to make cellulose foam with Pickering emulsion technology used cellulose nanofiber as a Pickering agent. The mechanism of Pickering emulsion is learned from foamability and stability of foam in the presence of various concentrations of surfactant. The result showed that using Pickering emulsion technology only needed surfactant with a small concentration to improve foamability and stability. The addition of CNF indeed improved the stability and foamability with the Pickering effect. The stability test shows that the foam stabilized with CNF appeared to be relatively stable. In contrast to the CNF free system, the foams were collapse in three days tested. Structures of foam was characterized using an optical microscope and showed that the foam was composed into two- or three dimensional microstructures formed by gas bubble of wet foam in random orientations. This process generated the lightweight Cellulose foam from OPEFB waste, with a density of 0.07 g/cm3. Using Pickering emulsion technology to make cellulose foam can be one way to overcome OPEFB waste and this foam is potential for various applications
ANALISIS ELEMEN HINGGA TEGANGAN TERMAL PADA PADUAN Fe-11Al.
No full textANALISIS ELEMEN HINGGA TEGANGAN TERMAL PADA PADUAN Fe-11Al. Program ANSYS berbasis Metode Elemen Hingga telah digunakan untuk menganalisis tegangan termal pada lapisan alumina vang terbentuk selama oksidasi suhu tinggi pada paduan Fe-11A1. Model simulasi mengasumsi pada perilaku elastik murni dari lapisan oksida serta perilaku elastik-plastik ideal dari logam substratnya. Pengkajian terhadap efek relaksasi tegangan oleh deformasi plastik substrat dan efek geometri oksida yang terbentuk oleh oksida berbentuk flat, konvolusi, dan konvolusi berpori telah dilakukan. Hasil perhitungan memperlihatkan bahwa di bawah kondisi suhu tertentu. tcgangan tarik dari oksida berbentuk konvolusi berpori mencapai 678 MPa - 2 GPa dan dapat melebihi kekuatan tarik σx dari lapisan aluminanya. Hasil perhitungan tegangan ini bersesuaian dengan pengamatan
AUTOCLAVE-ASSISTED DEACETYLATION: A RAPID METHOD TO RECYCLING CIGARETTE BUTTS TO CELLULOSE
Get PDFAUTOCLAVE-ASSISTED DEACETYLATION: A RAPID METHOD TO RECYCLINGCIGARETTE BUTTS INTO CELLULOSE. Cellulose acetate (CA)-based materials, like cigarette butts (CBs), become one of the most com-mon types of litter in the world. The toxic substances that are contained make this waste carry a hazardous risk for the environment and living organisms. Herein we report a rapid method for recycling cigarettes butts into more environmen-tally material. Cellulose was fabricated by deacetylation of cigarette butts with NaOH solution at various times 15, 30, 45, and 60 minutes in autoclave. Cellulose was optimized by a degree of deacetylation (DD%) and was further charac-terized by FTIR, SEM, TGA, and DSC analysis. The DD% and FTIR results confirmed the complete conversion of cellu-lose acetate from cigarette butts to cellulose within 15 minutes. Cellulose morphology under SEM showed the surface became rougher and textured after autoclave treatment. The results of autoclave-assisted deacetylation are comparable with the conventional deacetylation. Our rapid method offers substantially reduced deacetylation from 24 hours to just 15 minutes. This study has shown that the new and straightforward method for deacetylation cellulose acetate and it is potential as an alternative method for recycling cigarette butts waste in the future
STUDI KETAHANAN KOROSI BAJA TAHAN KARAT AUSTENITIK UNTUK MATERIAL ORTOPEDI
Get PDFSTUDI KETAHANAN KOROSI BAJA TAHAN KARAT AUSTENITIK UNTUK MATERIAL ORTOPEDI. Dalam upaya mencari bahan alternatif untuk material implant dalam bedah ortopedi, telah dilakukan penelitian ketahanan korosi pada tiga varian baja tahan karat austenitik non standar Al-6X (Alleghenyludlum) dengan kandungan Mo masing-masing: 4%, 5%, dan 6%. Pengujian dilakukan dengan metode CMS (Corrosion Measurement System) dalam media larutan garam NaCl. Logam contoh uji terlebih dahulu dipanaskan didalam tungku pada suhu 1150 0C agar terjadi proses pelarutan unsur-unsur (Solution Treatment), selanjutnya dicelup cepat (Quenching) dalam air pada suhu kamar. Sebagai pembanding digunakan baja standar AISI 316Lyang sudah banyak digunakan dipasaran sebagai implant dalam bedah ortopedi. Hasil pengujian pada suhu kamar menunjukkan bahwa laju korosi ketiga varian baja Al-6X masih lebih tinggi dari pada baja AISI 316L. Ketahanan korosi baja Al-6X paling tinggi dicapai pada varian baja dengan kandungan 4% Mo
THE EFFECT OF CALCINATION TEMPERATURE TO THE COMPOSITE CHARACTERISTICS OF TiO2SiO2 NANOPARTICLE
Get PDFTHE EFFECT OF CALCINATION TEMPERATURE TO THE COMPOSITECHARACTERISTICS OF TiO2SiO2 NANOPARTICLE. Self-cleaning material is a material that utilizes the photocatalytic property to degrade organic and inorganic compounds with the help of UV light. One of the materials that have good photocatalytic property is TiO2, the photocatalytic property causes TiO2 to be amphiphilic: becomes hydrophilic when there is light and becomes hydrophobic when there is no light. The photocatalytic property of TiO2 can be improved with the addition of buffer material such as SiO2. TiO2SiO2 nanoparticle was synthesized using a sol-gel method with Titanium (IV) Isopropoxide (TTIP) precursors for TiO2 and Tetraethyl Orthosilicate (TEOS) precursors for SiO2 and followed by a variation of calcination temperature of 400 °C, 450 °C, 500 °C, and 550 °C for 2 hours. TiO2SiO2 composite was synthesized using composition TiO2 sol 75% and SiO2 25%. The result of the synthesis TiO2SiO2 composite was characterized by Fourier Transform Infra-Red (FT-IR) instrument to determine the functional groups in the composites and X-Ray Diffraction (XRD) instruments to determine the phase, crystallite size and degree of crystallinity in the composite. The purpose of this research is to synthesized TiO2SiO2 nanoparticle as a self cleaning agent with variation of the calcination temperature, to obtain composite characteristics that can support self cleaning. The self-cleaning ability was based on a produced composite characteristic of TiO2SiO2. The result of FTIR characterization showed that at calcination temperature of 400 °C, 450 °C, 500 °C, and 550 °C there was a Ti-OSi bond at the peak of 948.91 cm-1, 950.77 cm-1, 941.13 cm-1, 942.13 cm-1. The result of XRD characterization showed that at the temperature of 400 °C had the best characteristics, the 75.27% anatase phase and brookite phase 24.72%. Calcinations temperature 400 °C had best degree of crystallinity of 91.66%