Pembuatan Dan Karakteristik Serbuk Piezoelektrik Pb(Zr,Ti)03 Tanpa Subtitusi Dan Dengan Nb Substitusi

The characteristics of chemically prepared piezoelectric PZT and doped PZT with niobium (PNZT) were investigated. PZT 55/45, both unmodified and doped with Nb2O5 were prepared by the hydrolysis of metal alkoxides and solid state reaction from PbO, ZrO, and TiO,. The average particle size was 0.45 um. X-ray diffraction results indicated that transformation of the amorphous precipitate be came well crystallized PZT after heating at 500 °C for 6 hours. DTA results suggested theformation of an intermediate PbTiO3 phase at 490 °C. Using X-ray diffractton can be investigated occurring of both tetragonal and rombohedral ferroelectric PZT phases. That case depends on the initial mixing of chemical composition. The PZT powders which prepared from alkoxides were agglomerated easly at low temperature calcining. Poor sintered bodies will he resulted it was calcinated above 600°C. Powders calcined at 500 °C for 6 hours and sintered at 1200 °C produced high body densities approaching 95% of theoretical density.The experimental results suggest that intimate mixing of constit uents during the hdrolyt ic decomposition produces a homogeneous powder. However, differences in the rate hydrolysis or polymerization of the respective metal alkoxides fend to couse the stoichiometric results difficult to be found

Sol-gel Process for the Manufacturing of Translucent Lead Zirconate Titanate Gel-monolith

Translucent Lead Zirconate Titanate (PZT) gel-monolith was prepared by partially hydrolyzing metal alkoxides solution which modified with acetylacetone(acacH). Metal alkoxides, lead di-i-propoxide, zirconium tetra-nbutoxide and titanium tetra-i-propoxide were used as starting materials. In Infrared spectra for the translucent monolithic gel after aging at room temperature for several days or drying at 90°C for 18h, the most significant feature is the presence of band at around 1554 cm-1 which can be assigned to the v (C-O) and v (C-C) vibrati-ons of acetylacetanate group coordinated to the metal cations Ti and Zr. The diffraction peaks of PbO were found after heating at 300°C for 2h. After heating at 450 °C for 2 h, diffraction peaks of pyrochlore Pb2 Ti206 and perovskite PZT phase were observed. The diffraction peaks of PbO and pyrochlore phase disappeared after heating at 600°C, and tetragonal perovskite phase was stable up to 1000 °C. The diffraction peaks of perovskite phase were also found after heating at 430 ° for 24 h. The density of the compacted pulverizedgel after heating at 1000°C for 30 min. was 6.9 g/cm3 , about 86% of the theoretical value

Pengaruh Metode Pemisahan Pelarut Dalam Gel Terhadap Sifat Fisik Titania-alumina Sebagai Penyangga Katalis

PENGARUH METODE PEMISAHAN PELARUT DALAM GEL TERHADAP SIFAT FISIK TITANIA-ALUMINA SEBAGAI PENYANGGA KATALIS. TiO2-Al2O3 gel monolitik dalam nisbah mol 0,2 untuk TiO2 dan 0,8 untuk Al2O3 telah dibuat dengan cara hidrolisis dari aluminium sec-butoksida, Al (OC4H9sec)3 dan titanium isopropoksida Ti(OC3H7iso)4 dalam larutan n-propanol dengan katalis asam. Pemisahan pelarut dalam gel dilakukan dengan dua cara, pertama pengeringan pada tekanan atmosfer hingga terbentuk xerogel. Kedua, pemisahan pelarut pada kondisi CO2 superkritik, hingga terbentuk aerogel. Terbentuknya gugus Ti-O, salah satu dari titanium dioksida atau jaringan polimer –Ti-O-Ti-O-Al-O- ditunjukkan dengan adanya puncak antara 500 dan 900 cm-1 yang tajam tetapi lebar pada spektrum infra merah. Puncak yang kuat pada 1635 cm-1 menandakan adanya gugus –OH uluran yang merupakan derajat yang tinggi dari permukaan hidroksilasi. Volume kumulatif pori-pori dari xerogel sangat kecil jika dibandingkan dengan aerogel hasil pemisahan pelarut pada kondisi CO2 superkritik. Fase anatase TiO2 tidak terbentuk selama proses kristalisasi hingga kalsinasi sampai suhu 1000oC. Pengkristalan alumina terjadi secara langsung dari fasa amorf Al2O3 ke fasa α-Al2O3 dan fasa-fasa antara θ- dan γ-Al2O3 tidak teramati. Dari hasil tersebut dapat diperkirakan bahwa selama kalsinasi partikel TiO2 terpisah dari partikel Al2O3 membentuk inti atom rutil sebelum terbentuknya kristal α-Al2O3. Karena itu pembentukan fasa rutile TiO2 akan mempercepat terbentuknya fasa α-Al2O3. Keasaman campuran titania alumina setelah dikalsinasi pada suhu 500 oC lebih tinggi daripada oksidanya masing-masing, yaitu TiO2 dan Al2O3. Hal ini disebabkan oleh terbentuknya asam Lewis dari campuran titania-alumina

Preparation of Lead Zirconate Titanate Film by Sol-gel Method and Its Characterization

A ferroelectric material film of Lead Zirconate Titanate, Pb(Zr,Ti)O3 (PZT), was produced by sol-gel method from alkoxide and acetate precursors in a normal propanol solvent system. The excess amount of Pb was 10 mole % more than stoichiometrically used for preparing the solution. The concentration of PZT in coating solution was 0.7 M, and pH of the solution was 4.5. The films was prepared by dip-coating onto slide glass, silica glass and Pt/Ti/SiO2/Si substrate. In order to avoid cracking TiO2 was coated on the glasses as a barrier layer. The asdried PZT film was amorphous from X-ray diffraction. The amount of pyrochlore and perovskite phase depended on the heating temperature and kind of barrier layer. Single perovskite phase was found for coated films on TiO2/SiO2 and Pt/Ti/SiO2/Si heated at 600° C or higher, but it was never found for coated films on SiO2 substrate without barrier layers. Crystallization of perovskite PZT film was retarded when deposited on amorphous substrates as compared to crystalline substrate. The coated film on Pt/Til/SiO2/Si was thicker and smaller in particle size than that of coated film on Ti02/SiO2. A columnar structure with a diameter around 6.5 nm, was observed and no boundary was observed between layers in 9 time dipcoated film on Pt/Ti/SiO2/Si

Carbonization of Palm Oil Empty Fruit Bunch (EFB) in Hydrothermal Processes to Produce Biochar

Empty fruit bunch (EFB) of palm oil is a waste from the palm oil industries which in a large amount, those waste is not properly utilized yet. EFB is a lignocelluloses waste as a polymer with big molecule such as cellulose, lignin, and hemicelluloses that can be degraded into smaller molecules in hydrothermal carbonization (HTC) process. The HTC process of EFB will result three fractions such as gas, organic water soluble and biochar as solid residue or bio-char-water-slurry. EFB degradation is influenced by the operation conditions such as temperature, pressure, catalysts, reaction time, stirring and ratio liquid and solid. The HTC process involved many routes of reaction such as liquefaction, hydrolysis, dehydration, decarboxylation, condensation, aromatization, and polymerization. In this experiment 60 ml closed vessel was used as the HTC reactor to degrade of EFB. EFB concentration of 6.44% resulted 62% of conversion. Reaction time of 6 hours resulted 62 % of conversion. Increasing the reaction time and temperature increase the conversion of EFB. Liquid products of organic water soluble has cleared yellow color, after several hours the color become darkness that is further reaction still occurs in that solution. Solid products is biochar as brown coal, that can be easily separated and processed into powder, pellet or briquette form with outstanding storage and transport characteristics. For further economic development, biochar with excellent transport characteristics, the possibility of exporting this commodity to the world's energy market is possible

Crystallization Behavior And Micromorphology Of Sol-gel Derived Mesoporous Nano-particles Titania

CRYSTALLIZATION BEHAVIOR AND MICROMORPHOLOGY OF SOL-GEL DERIVED MESOPOROUS NANO-PARTICLES TITANIA. In this work, effects of drying methods on the micro-morphology ofinesoporpous TiO2 prepared by the sol-gel method has been studied using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD) and N2 gas adsorption. Mesoporous TiO2 consists of anatase nano-particles, about 5nm in diameter, have been obtained by hydrolysis of titanium alkoxide in a methanol solution and supercritical extraction in CO2 at 60°C and 22Mpa. XRD peaks ofrutile have been found after annealing at 600°C. The particle sizes of anatase and rutile are about 13 and 25nm in diameter, respectively. The surface morphology of Ti02 nano-particles has been discussed with the surface fractal dimensions estimated from the N2 gas adsorption isotherms