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Thermal stability effect of H4[PVMo11O40]/SiO2
Full text linkSynthesis and characterization of supported polyoxometalate H4[PVMo11O40].nH2O with SiO2 through sol-gel method have been done. The compound H4[PVMo11O40]/SiO2 was characterized through FT-IR spectrophotometer, XRD, and SEM-EDX. The results showed that FT-IR spectrum of H4[PVMo11O40]/SiO2 has the primary vibration on wavenumber at 1064.7 cm-1 (P-O); 964.4 cm-1 (Mo=O); 864.1 cm-1 (Mo-Oe-Mo); 779.2 cm-1 (Mo-Oc-Mo); 462.9 cm-1 (Si-O); and 1087.9 cm-1 (Si-O-Si). The XRD diffraction pattern showed that H4[PVMo11O40].nH2O has the highest crystallinity. However, after it’s supported with SiO2, the properties of crystallinity has decreased due to the excess water during the support process. The result of SEM-EDX showed that H4[PVMo11O40]/SiO2 material has homogeneous distribution with particle size distribution of 1330 nm (1,33 μm). The acidity test by qualitative and quantitative methods show that H4[PVMo11O40]/SiO2 more acidic than H4[PVMo11O40].H2O. The effect temperature on the crystallinity showed that increasing calcination temperature made the crystallinity properties of H4[PVMo11O40]/SiO2 increased.
Keywords : polyoxometalate, H4[PVMo11O40].nH2O, SiO2
Preparation, characterization, and thermal stability of B2O3-ZrO2
Full text linkSynthesis of the borate-based compound with ZrOCl2 to form B2O3-ZrO2 has been conducted. The compound was characterized by FT-IR spectrophotometer, X-ray diffraction, acidity and thermal stability test. The results showed that the FT-IR main vibration spectrum of B2O3-ZrO2 compound has appeared at wave number 401.2 cm-1 for Zr-O bonding vibration, 617.2 cm-1 for B-O-B bonding vibration and 910.4 cm-1 for B-O bonding vibration. The XRD diffraction pattern shows B2O3-ZrO2 compound has an amorphous structure. The FT-IR spectrum after saturated with ammonia and potentiometric titration indicates that the compound of B2O3-ZrO2 has acidic properties with a strong level of acidity. Thermal stability test shows that the B2O3-ZrO2 compounds have high stability on temperature with increasing crystallinity after the compound was heated at 700 °C.
Keywords: B2O3-ZrO2, impregnation, thermal stability.  
Preparation of polyoxometalate compound (NH4)6(β-P2W18O62)/SiO2 by sol-gel method and its characterization
Full text linkPreparation of polyoxometalate compound of (NH4)6(β-P2W18O62)nH2O supported with silica derived from the hydrolysis of tetraethyl orthosilicate by sol-gel method has been conducted. The compound was synthesized and characterized using FT-IR spectrophotometer, crystallinity using XRD analysis and the determination of acidity via quantitatively and qualitatively. Qualitative analysis was performed using ammonia and pyridine adsorption and quantitative analysis using potentiometric titration. FT-IR spectrum of (NH4)6(β-P2W18O62)nH2O appeared in wavenumber 786.96 cm-1 (W-OC-W), 918.12 cm-1 (W-Oe-W), 964.41 cm-1 (W=O), 1087.85 cm-1 (P-O), 3572.17 cm-1 (O-H), 1404.18 cm-1 (N-H) reinforced with wavenumber 1612.49 cm-1 with show vibration NH dari NH+, and to (NH4)6(β-P2W18O62)nH2O/SiO2 appears in wavenumbers 794.67 cm-1 (W-Oc-W), 918.12 cm-1 (W-Oe-W), 1049.28 cm-1 (W=O), 1087.85 cm-1 (P-O), 3564.15 cm-1 (O-H), 470.63 cm-1 (Si-O). Diffraction pattern of (NH4)6(β-P2W18O62)nH2O and (NH4)6(β-P2W18O62)nH2O/SiO2 compound show high crystanillity. The acidic properties showed (NH4)6(β-P2W18O62)nH2O/SiO2 more acidic than (NH4)6(β-P2W18O62)nH2O. Analysis of the effect of temperature on the stability of the compounds polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2 show that the temperature of 600ºC the shift in wavenumbers of the compounds caused by vibration W=O, W-OC-W, W-Oe-W has been lost. This shows that at a temperatures of 600ºC on heating can cause changes in the structure of polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2.
Keywords : (NH4)6(β-P2W18O62).nH2O, Polyoxometalate, SiO
Adsorption of procion red using layer double hydroxide Mg/Al
Full text linkLayer double hydroxide Mg/Al was synthesized by inorganic synthetic method. Material was characterized using FTIR and XRD analyses and used as adsorbent of procion red dye in aqueous medium. Factors that affect the adsorption process are adsorption time as the kinetic parameter; and the temperature and concentration of procion red as the thermodynamic parameter. FTIR spectra of layer double hydroxides showed unique vibration at wavenumber 1300 cm-1 and 1600 cm-1. Characterization using XRD shows diffraction angles at 29o, 27o, and 28o, which are typical of Mg/Al double layer hydroxides. Adsorption of procion red using layer double hydroxide Mg/Al resulted adsorption rate 7.1 minutes-1, maximum adsorption capacity 111.1 mg/g at 60 oC with increasing energy by increasing adsorption temperature.
Keywords: Layered double hydroxides, adsorption, procion red
Pillarization of double layer hydroxides using H3[-PW12O40]nH2O: effect of pillarization time
Full text linkThe pillarization of Mg/Al double layer hydroxides using polyoxometalate H3[α-PW12O40]·nH2O by comparing the pillarization time i.e. 3 hours, 6 hours, 9 hours, 12 hours, 24 hours, 36 hours and 48 hours has been done. The product of a pillarization was characterized using an FT-IR spectrophotometer and XRD analysis. The result characterization of FT-IR spectrophotometer does not show the optimum of pillarization each time condition. Characterization using XRD shows the optimum pillarization process at 36 hours by showing the existence of double layer hydroxides material at diffraction angle 11.69o deg, 18.30o deg and 34.71o deg. Diffraction in the 60o-63o deg indicates the existence of a pillarization double layer hydroxides.
Keywords: Layered double hydroxides, pillarization, polyoxometalate H3[α-PW12O40]·nH2O
Modification of (Dioscorea alata l) starch with propylene oxide to make edible film
Full text linkThe research about modification uwi starch (Dioscorea alata L) by using propylene oxide has been done. Concentration of propylene oxide were 6%(v/w), 8%(v/w), and 10%(v/w). The amilograf parameter after modification were characteristic breakdown viscosity 43 BU and setback viscosity 975 BU. The modification starch has edible properties according to FDA (food and drug administration) which have degree of modification < 7%, degree of substitution < 0,1 and propylene oxide concentration < 10%(v/w). The best propylene oxide in making of edible film was 8 %( v/w). The starch control can be made into edible film with thickness 0,136 mm, tensile strength 20,4605 MPa and elongation 22%. Modification starch of uwi can be made into edible film with thickness 0,146 mm, tensile strength 25, 3521 Mpa, elongation 30% and water vapor transmission 7, 2651 g/m2/24 hours. FTIR characterization of uwi starch showed the occurrence of hydroxypropylation. The peak spectrum at 2900 cm-1 showed bonding of C-H from methyl group, which is characteristic for modification starch with hydroxypropyl. Characterization with scanning electron microscopy showed that modification of uwi starch has turned the granule of starch to be fully swallon
Bamboo distribution in Musi Rawas District South Sumatera Province
Full text linkIndonesia is estimated to have 157 species of bamboo which is more than 10% of the world\u27s bamboo species. Almost 50% of bamboo growth in Indonesia is endemic bamboo and more than 50% of bamboo species life in Indonesia have been utilized by the society conventionally. Further, the bamboo utilization is still having high potential to be developed by increasing the industrial development. This research aimed to investigate the diversity of the bamboo species in South Sumatera, particularly in Musi Rawas district. The result showed that in Musi Rawas district of South Sumatera province there are 10 species of bamboo located at 11 locations in protected forest area of 883.60 ha and production forest area of 177,976.26 ha. The large number of bamboo potentials viewed from various aspects and the many types of bamboo scattered in this district can be a supporting data in doing bamboo conservation efforts, especially in Musi Rawas district of South Sumatra province