The effect of a nickel oxide supported silica oxide (NiO/SiO2) catalyst on temperature programmed... more The effect of a nickel oxide supported silica oxide (NiO/SiO2) catalyst on temperature programmed reduction (TPR) with 40% (v/v) carbon monoxide (CO) in nitrogen atmosphere as reductant agent was investigated. The conventional impregnation method was used to create the NiO/SiO2 catalysts. The reduction characteristics of NiO to Ni were investigated up to 700 °C, followed by isothermal reduction. The TPR profile of 9% NiO/SiO2 slightly shifted to lower temperature from 412 to 392 ºC. Whereas the undoped NiO was reduced at a lower temperature of 387 ºC. XRD diffractogram of the catalysts showed a complete reduction of NiO to Ni and have different intensities for each different loading of NiO catalyst on SiO2 support. The TEM images indicated that the carbon nanotubes were deposited on the NiO surfaces indicating some chemical reactions occur on NiO. It was found that the addition of 3% of NiO on SiO2 also exhibited a larger BET surface area (532.8 m 2 g-1) and insignificant pore diameter (5.9-6.0 nm). Based on these results, it is interesting to note that the addition of a small amount of NiO to SiO2 has a remarkable influence by reducing the temperature in the reduction process. The 9% NiO/SiO2 was found sufficient could enhance the reducibility of NiO at a lower temperature.
A study of elemental and chemical composition of Nafion® 117 electrolytic surface was conducted u... more A study of elemental and chemical composition of Nafion® 117 electrolytic surface was conducted using X-ray photoelectron spectroscopy. The major chemical compositions of the membrane surface were mainly fluorine, carbon, oxygen, sulphur and titanium with mass ...
Industrial & Engineering Chemistry Research, Mar 24, 2016
Various type iron oxides of FeO, Fe2O3, and Fe3O4 were used for carbon dioxide (CO2) capture at r... more Various type iron oxides of FeO, Fe2O3, and Fe3O4 were used for carbon dioxide (CO2) capture at room temperature and pressure by studying its adsorption–desorption properties. Several interactions of carbonate species were detected on its surface. The morphology of carbonate formation shows different structures on FeO (grooves-like), Fe2O3 (fine sharp particles), and Fe3O4 (aggregated nanoparticles). CO2 chemisorption discovered a potential adsorbent of Fe2O3 with an adsorption capacity of 3.95 mgCO2/gadsorbent. The adsorption capacity increased up to 62.8% by using concentrated 99.9% CO2 for adsorption. At higher concentration of CO2 exposure, it partially turns to red color which indicated the less stable Fe3O4 was easily oxidized to Fe2O3 after CO2 regeneration with temperatures up to 500 °C. Hence, Fe2O3 possessed the highest basicity strength (1.26 cm3/g), and the adsorption capacity after four cycles was not significantly reduced by 8.6% indicating an effective chemical or physical adsorption in CO2...
Covalent functionalization of azide-modified SiO(2) with well-defined, alkyne-terminated poly(N-i... more Covalent functionalization of azide-modified SiO(2) with well-defined, alkyne-terminated poly(N-isopropylacrylamide) was accomplished by the Cu(I)-catalyzed [3 + 2] Huisgen cycloaddition. The alkyne-terminated RAFT chain transfer agent was first synthesized, and then the alkyne-terminated thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) with different molecular weights were synthesized by the RAFT of NIPAM monomer. The polymerization kinetics and the evolution of number-average molecular weights (M(n)), and polydispersities (M(w)/M(n)), with monomer conversions were investigated. A copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) "grafting to" method was used to attach thermoresponsive polymers onto the exterior surface of SiO(2) nanoparticles which produced relatively high grafting density. The as-synthesized hybrid nanoparticles showed thermoresponsive behavior and were characterized by FTIR, XPS, TGA, DLS, and TEM, etc.
This project is devoted to be mixed oxide niobium catalyst in environmental remediation purposes.... more This project is devoted to be mixed oxide niobium catalyst in environmental remediation purposes. Niobium oxides and mixed oxides as well as sulfides, nitrides (oxynitrides), carbides (oxycarbides), and phosphates are considered. Among the catalyyic processes, Nb-containing materials were tested under ambient and corrosive environment. The role of niobium porous in absorbing the sulphite and nitride component was also investigated. The surface chemical composition of Nb samples prepared by following procedures commonly employed in the sample preparation using X-ray Photoelectron (XPS) and Angle Resolved X-ray Photoelectron (ARXPS). The series of ambient and corrosive exposure analysis was performed in order to monitor the development of oxide on the sample surfaces as it reacts with the oxygen, sulfur dioxide and nitrogen dioxide. During the exposure phase, it was found that there is a progressive reduction of Nb oxides from NbO, NbO2 and finally Nb2O2. The O photoelectron signal ex...
Carbon dioxide (CO 2) capture by the bimetal composite of strontium oxide impregnated on iron(III... more Carbon dioxide (CO 2) capture by the bimetal composite of strontium oxide impregnated on iron(III) oxide (SrO/Fe 2 O 3) was studied. The adsorbent was calcined at 200-600°C and their adsorption capacities including adsorption and desorption were investigated. The adsorbents were characterized using X-ray diffraction (XRD), N 2 adsorption-desorption isotherm, CO 2 adsorption isotherm at 25°C, 1 atm and temperature programmed desorption for CO 2 (CO 2-TPD). The SrO/Fe 2 O 3-200 was observed to be the most efficient with adsorption capacity for physisorption and chemisorption of 5.08 and 100.03 mg CO 2 /g adsorbent respectively. It exhibited a lower maximum desorption temperature of 523°C compared to SrO and Fe 2 O 3 only. The order of best fit linearized adsorption isotherm models for CO 2 adsorption isotherm is Freundlich > Dubinin-Radushkevich > Temkin > Langmuir. The Freundlich isotherm possesses Freundlich constant, n = 1.196 corresponded to favorable adsorption, highest R 2 value (0.98) and the calculated adsorption quantity closest to the experimental value. Adsorption process governed by CO 2 molecules forms a successive multilayer on the SrO/Fe 2 O 3-200 surfaces and mainly exhibits a physisorption process. The heat of adsorption (b T = 5.238 J/mol) from the Temkin isotherm suggests the adsorption is an exothermic reaction and mean free energy (E = 2886.8 J/mol) from Dubinin-Radushkevich isotherm indicates the CO 2 adsorption is physical in nature.
Nitrogen-doped TiO2 films were prepared by reactive ion-beam sputtering deposition (IBSD) in a mi... more Nitrogen-doped TiO2 films were prepared by reactive ion-beam sputtering deposition (IBSD) in a mixed atmosphere of NH3 and O2 at a substrate temperature of 400 °C. X-ray photoelectron spectra revealed the presence of six ions, i.e., N3−, N2−, N1−, N+, N2+, and N3+, respectively, in the films. The amorphous films had complex, randomly oriented chemical bonds. The Tauc–Lorentz model was employed to determine the bandgap energy of the amorphous films prepared using different NH3/O2 gas mixing ratios by ellipsometry. In addition, the optical constants of the films were measured. With the increase in the NH3/O2 gas mixture ratio to 3.0, the bandgap of N-doped TiO2 narrowed to ~2.54 eV.
Abstract Palm-based lauryl alcohol ethoxylate was synthesized with 6 moles of ethylene oxide usin... more Abstract Palm-based lauryl alcohol ethoxylate was synthesized with 6 moles of ethylene oxide using an ethoxylation reactor. The 6 moles of ethylene oxide chain length was approximately the same length as the palm-based lauryl alcohol. The synthesized lauryl ...
This paper reports on structural, optical transmittance and electrical properties of fluorine-dop... more This paper reports on structural, optical transmittance and electrical properties of fluorine-doped tin oxide (FTO) thin films deposited using an Inkjet printer. The FTO ink was synthesized from a mixture of tin chloride pentahydrate (SnCl4.5H2O) and ammonium fluoride (NH 4F) solutions. The thin films were deposited on glass substrates at ambient temperature or heated at 40deg;C and 60°C. The surface electronic state and the elemental composition of the thin films were analyzed using XPS spectroscopy. The spectra of the FTO thin films revealed that tin, oxygen, fluoride and carbon were present in the samples. The signals corresponding to Sn 3d5/2, O1s, and F1s were found at 486.6 eV, 530.5 eV and 684.5 eV, respectively. XRD analysis showed that the FTO films were in the form of crystalline with cassiterite shape. The optical and electrical properties of the films were affected by the deposition temperatures. It was observed the film deposited at 40°C has the optimum optical transmit...
Geopolymers, or inorganic polymers, have attracted a lot of attention due to their low manufactur... more Geopolymers, or inorganic polymers, have attracted a lot of attention due to their low manufacturing temperatures (<100 °C), which emits six times less CO2 compared to standard cement. They can also utilize different waste materials as raw materials. In this study, the rice husk (RH) and rice husk ash (RHA) were selected as a pozzolan raw material to prepare geopolymers. Different ratios of Na2SiO3/NaOH, at 1, 1.5, and 2.5 were used to prepare geopolymers. The effects of raw materials percentage and Na2SiO3/NaOH ratio on water absorption, density, and the compressive strength of the prepared geopolymers were also investigated. The results showed that the compressive strength of geopolymers increases with the ratio of alkali liquid.
The new dicarboxylate esters offer many of the advantages of lubrication such as high viscosity i... more The new dicarboxylate esters offer many of the advantages of lubrication such as high viscosity indices, good low temperature properties and good oxidative stability. In addition, they can be used as additive in lubricant to improve low temperature properties. Six branched dicarboxylate esters with different chemical structures were synthesized and tested in terms of their suitability as lubricants. The esterification reaction was carried out using a Dean Stark distillation method. Fourier transformation infra-red (FTIR); proton and carbon nuclear magnetic resonance (1H-NMR and 13C-NMR), and elemental analysis were used to verify the chemical structure of synthesized dicarboxylate esters. The results showed that the esters of dicarboxylate based on 2-ethyl-1-hexanol had very good low temperature properties with pour point values at -58oC for di-2-ethyhexyl dodecanedioate (D2EHD) and less than -60 oC of di-2-ethyhexyl azelate (D2EHAz) and di-2-ethyhexyl suberate (D2EHSub). The viscos...
The effect of a nickel oxide supported silica oxide (NiO/SiO2) catalyst on temperature programmed... more The effect of a nickel oxide supported silica oxide (NiO/SiO2) catalyst on temperature programmed reduction (TPR) with 40% (v/v) carbon monoxide (CO) in nitrogen atmosphere as reductant agent was investigated. The conventional impregnation method was used to create the NiO/SiO2 catalysts. The reduction characteristics of NiO to Ni were investigated up to 700 °C, followed by isothermal reduction. The TPR profile of 9% NiO/SiO2 slightly shifted to lower temperature from 412 to 392 ºC. Whereas the undoped NiO was reduced at a lower temperature of 387 ºC. XRD diffractogram of the catalysts showed a complete reduction of NiO to Ni and have different intensities for each different loading of NiO catalyst on SiO2 support. The TEM images indicated that the carbon nanotubes were deposited on the NiO surfaces indicating some chemical reactions occur on NiO. It was found that the addition of 3% of NiO on SiO2 also exhibited a larger BET surface area (532.8 m 2 g-1) and insignificant pore diameter (5.9-6.0 nm). Based on these results, it is interesting to note that the addition of a small amount of NiO to SiO2 has a remarkable influence by reducing the temperature in the reduction process. The 9% NiO/SiO2 was found sufficient could enhance the reducibility of NiO at a lower temperature.
A study of elemental and chemical composition of Nafion® 117 electrolytic surface was conducted u... more A study of elemental and chemical composition of Nafion® 117 electrolytic surface was conducted using X-ray photoelectron spectroscopy. The major chemical compositions of the membrane surface were mainly fluorine, carbon, oxygen, sulphur and titanium with mass ...
Industrial & Engineering Chemistry Research, Mar 24, 2016
Various type iron oxides of FeO, Fe2O3, and Fe3O4 were used for carbon dioxide (CO2) capture at r... more Various type iron oxides of FeO, Fe2O3, and Fe3O4 were used for carbon dioxide (CO2) capture at room temperature and pressure by studying its adsorption–desorption properties. Several interactions of carbonate species were detected on its surface. The morphology of carbonate formation shows different structures on FeO (grooves-like), Fe2O3 (fine sharp particles), and Fe3O4 (aggregated nanoparticles). CO2 chemisorption discovered a potential adsorbent of Fe2O3 with an adsorption capacity of 3.95 mgCO2/gadsorbent. The adsorption capacity increased up to 62.8% by using concentrated 99.9% CO2 for adsorption. At higher concentration of CO2 exposure, it partially turns to red color which indicated the less stable Fe3O4 was easily oxidized to Fe2O3 after CO2 regeneration with temperatures up to 500 °C. Hence, Fe2O3 possessed the highest basicity strength (1.26 cm3/g), and the adsorption capacity after four cycles was not significantly reduced by 8.6% indicating an effective chemical or physical adsorption in CO2...
Covalent functionalization of azide-modified SiO(2) with well-defined, alkyne-terminated poly(N-i... more Covalent functionalization of azide-modified SiO(2) with well-defined, alkyne-terminated poly(N-isopropylacrylamide) was accomplished by the Cu(I)-catalyzed [3 + 2] Huisgen cycloaddition. The alkyne-terminated RAFT chain transfer agent was first synthesized, and then the alkyne-terminated thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) with different molecular weights were synthesized by the RAFT of NIPAM monomer. The polymerization kinetics and the evolution of number-average molecular weights (M(n)), and polydispersities (M(w)/M(n)), with monomer conversions were investigated. A copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) "grafting to" method was used to attach thermoresponsive polymers onto the exterior surface of SiO(2) nanoparticles which produced relatively high grafting density. The as-synthesized hybrid nanoparticles showed thermoresponsive behavior and were characterized by FTIR, XPS, TGA, DLS, and TEM, etc.
This project is devoted to be mixed oxide niobium catalyst in environmental remediation purposes.... more This project is devoted to be mixed oxide niobium catalyst in environmental remediation purposes. Niobium oxides and mixed oxides as well as sulfides, nitrides (oxynitrides), carbides (oxycarbides), and phosphates are considered. Among the catalyyic processes, Nb-containing materials were tested under ambient and corrosive environment. The role of niobium porous in absorbing the sulphite and nitride component was also investigated. The surface chemical composition of Nb samples prepared by following procedures commonly employed in the sample preparation using X-ray Photoelectron (XPS) and Angle Resolved X-ray Photoelectron (ARXPS). The series of ambient and corrosive exposure analysis was performed in order to monitor the development of oxide on the sample surfaces as it reacts with the oxygen, sulfur dioxide and nitrogen dioxide. During the exposure phase, it was found that there is a progressive reduction of Nb oxides from NbO, NbO2 and finally Nb2O2. The O photoelectron signal ex...
Carbon dioxide (CO 2) capture by the bimetal composite of strontium oxide impregnated on iron(III... more Carbon dioxide (CO 2) capture by the bimetal composite of strontium oxide impregnated on iron(III) oxide (SrO/Fe 2 O 3) was studied. The adsorbent was calcined at 200-600°C and their adsorption capacities including adsorption and desorption were investigated. The adsorbents were characterized using X-ray diffraction (XRD), N 2 adsorption-desorption isotherm, CO 2 adsorption isotherm at 25°C, 1 atm and temperature programmed desorption for CO 2 (CO 2-TPD). The SrO/Fe 2 O 3-200 was observed to be the most efficient with adsorption capacity for physisorption and chemisorption of 5.08 and 100.03 mg CO 2 /g adsorbent respectively. It exhibited a lower maximum desorption temperature of 523°C compared to SrO and Fe 2 O 3 only. The order of best fit linearized adsorption isotherm models for CO 2 adsorption isotherm is Freundlich &gt; Dubinin-Radushkevich &gt; Temkin &gt; Langmuir. The Freundlich isotherm possesses Freundlich constant, n = 1.196 corresponded to favorable adsorption, highest R 2 value (0.98) and the calculated adsorption quantity closest to the experimental value. Adsorption process governed by CO 2 molecules forms a successive multilayer on the SrO/Fe 2 O 3-200 surfaces and mainly exhibits a physisorption process. The heat of adsorption (b T = 5.238 J/mol) from the Temkin isotherm suggests the adsorption is an exothermic reaction and mean free energy (E = 2886.8 J/mol) from Dubinin-Radushkevich isotherm indicates the CO 2 adsorption is physical in nature.
Nitrogen-doped TiO2 films were prepared by reactive ion-beam sputtering deposition (IBSD) in a mi... more Nitrogen-doped TiO2 films were prepared by reactive ion-beam sputtering deposition (IBSD) in a mixed atmosphere of NH3 and O2 at a substrate temperature of 400 °C. X-ray photoelectron spectra revealed the presence of six ions, i.e., N3−, N2−, N1−, N+, N2+, and N3+, respectively, in the films. The amorphous films had complex, randomly oriented chemical bonds. The Tauc–Lorentz model was employed to determine the bandgap energy of the amorphous films prepared using different NH3/O2 gas mixing ratios by ellipsometry. In addition, the optical constants of the films were measured. With the increase in the NH3/O2 gas mixture ratio to 3.0, the bandgap of N-doped TiO2 narrowed to ~2.54 eV.
Abstract Palm-based lauryl alcohol ethoxylate was synthesized with 6 moles of ethylene oxide usin... more Abstract Palm-based lauryl alcohol ethoxylate was synthesized with 6 moles of ethylene oxide using an ethoxylation reactor. The 6 moles of ethylene oxide chain length was approximately the same length as the palm-based lauryl alcohol. The synthesized lauryl ...
This paper reports on structural, optical transmittance and electrical properties of fluorine-dop... more This paper reports on structural, optical transmittance and electrical properties of fluorine-doped tin oxide (FTO) thin films deposited using an Inkjet printer. The FTO ink was synthesized from a mixture of tin chloride pentahydrate (SnCl4.5H2O) and ammonium fluoride (NH 4F) solutions. The thin films were deposited on glass substrates at ambient temperature or heated at 40deg;C and 60°C. The surface electronic state and the elemental composition of the thin films were analyzed using XPS spectroscopy. The spectra of the FTO thin films revealed that tin, oxygen, fluoride and carbon were present in the samples. The signals corresponding to Sn 3d5/2, O1s, and F1s were found at 486.6 eV, 530.5 eV and 684.5 eV, respectively. XRD analysis showed that the FTO films were in the form of crystalline with cassiterite shape. The optical and electrical properties of the films were affected by the deposition temperatures. It was observed the film deposited at 40°C has the optimum optical transmit...
Geopolymers, or inorganic polymers, have attracted a lot of attention due to their low manufactur... more Geopolymers, or inorganic polymers, have attracted a lot of attention due to their low manufacturing temperatures (<100 °C), which emits six times less CO2 compared to standard cement. They can also utilize different waste materials as raw materials. In this study, the rice husk (RH) and rice husk ash (RHA) were selected as a pozzolan raw material to prepare geopolymers. Different ratios of Na2SiO3/NaOH, at 1, 1.5, and 2.5 were used to prepare geopolymers. The effects of raw materials percentage and Na2SiO3/NaOH ratio on water absorption, density, and the compressive strength of the prepared geopolymers were also investigated. The results showed that the compressive strength of geopolymers increases with the ratio of alkali liquid.
The new dicarboxylate esters offer many of the advantages of lubrication such as high viscosity i... more The new dicarboxylate esters offer many of the advantages of lubrication such as high viscosity indices, good low temperature properties and good oxidative stability. In addition, they can be used as additive in lubricant to improve low temperature properties. Six branched dicarboxylate esters with different chemical structures were synthesized and tested in terms of their suitability as lubricants. The esterification reaction was carried out using a Dean Stark distillation method. Fourier transformation infra-red (FTIR); proton and carbon nuclear magnetic resonance (1H-NMR and 13C-NMR), and elemental analysis were used to verify the chemical structure of synthesized dicarboxylate esters. The results showed that the esters of dicarboxylate based on 2-ethyl-1-hexanol had very good low temperature properties with pour point values at -58oC for di-2-ethyhexyl dodecanedioate (D2EHD) and less than -60 oC of di-2-ethyhexyl azelate (D2EHAz) and di-2-ethyhexyl suberate (D2EHSub). The viscos...
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