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"Nanostructured zincoxide (ZnO) was synthesized via a sonochemical method. The effect of the duration of ultrasonic irradiation in a continuous mode on the generated particles was investigated. Additionally, the effect of flowing either air or nitrogen during the sonication process was investigated. Zinc nitrate andammonia water-based solutions were selected as chemicals without the additionof other surfactants. The generated particles indicated that a wurtzitestructure of ZnO in a hexagonal phase was formed with a crystalline size that increasedas the ultrasound irradiation time increased. The morphology of the generatedZnO particles could be changed from flowerlike to needlelike structures viacontinuous ultrasound irradiation over one to two hours, resulting in increasesin the particle lengths and decreases in the particle diameters from 200 to 80nm. Photoluminescence intensity was also increased with increases in the ultrasonicirradiation times. Photoluminescence spectra were also influenced by theatmospheric environment. Two bands centered at 390 and 500 nm were generatedunder a nitrogen environment. On the other hand, a single wide band with a peakat around 430 nm was found for particles generated under an air environment. Itcan be applied for light emitting diodes (LED) or laser fabrication with acontrolled emitting band."

"Nanostructured zinc oxide (ZnO) was synthesized via a sonochemical method. The effect of the duration of ultrasonic irradiation in a continuous mode on the generated particles was investigated. Additionally, the effect of flowing either air or nitrogen during the sonication process was investigated. Zinc nitrate and ammonia water-based solutions were selected as chemicals without the addition of other surfactants. The generated particles indicated that a wurtzite structure of ZnO in a hexagonal phase was formed with a crystalline size that increased as the ultrasound irradiation time increased. The morphology of the generated ZnO particles could be changed from flowerlike to needlelike structures via continuous ultrasound irradiation over one to two hours, resulting in increases in the particle lengths and decreases in the particle diameters from 200 to 80 nm. Photoluminescence intensity was also increased with increases in the ultrasonic irradiation times. Photoluminescence spectra were also influenced by the atmospheric environment. Two bands centered at 390 and 500 nm were generated under a nitrogen environment. On the other hand, a single wide band with a peak at around 430 nm was found for particles generated under an air environment. It can be applied for light emitting diodes (LED) or laser fabrication with a controlled emitting band."

"Fabrikasi kompleks Tb[EO4-Pic] ke dalam bentuk mikropartikel dengan metode represipitasi-penguapan telah berhasil dilakukan dalam penelitian ini, dimana EO4 = tetraetilena glikol, Pic = anion pikrat. Untuk perbandingan dikaji juga fabrikasi dengan metode In situ. Mikropartikel kompleks Tb[EO4-Pic] yang dihasilkan didispersikan ke dalam matriks polimer polimetilmetaakrilat (PMMA) menjadi komposit Tb[EO4-Pic]/PMMA. Komposit dilapiskan pada substrat dengan teknik spin-coating. Pada penelitian ini dikaji juga pengaruh polimer dan substrat terhadap sifat luminesensi dari mikropartikel kompleks Tb[EO4-Pic] dan kompositnya. Ukuran partikel dan fluoresensi dari mikropartikel kompleks Tb[EO4-Pic] dan kompositnya masing-masing diukur dengan Particle Size Analyzer dan spektrofluorometer. Partikel komposit yang dibuat dengan metode represipitasi-penguapan berukuran lebih kecil (191,0 nm) dibandingkan yang diperoleh dengan metode In situ (431,8 nm). Puncak hipersensitif pada 548 nm (transisi 5D4 à 7F5) sebagai karakter ion terbium(III) meningkat dengan kenaikan rasio intensitas transisi 5D4 à 7F5 terhadap transisi 5D4 à 7F6 dari 9,31 menjadi 11,87 yang disebabkan oleh adanya polimer dan kenaikan rasio intensitas dari 7,38 menjadi 48,50 yang disebabkan oleh pelapisan komposit pada substrat aluminum permukaan kasar. Mikropartikel kompleks Tb[EO4-Pic] dan kompositnya dapat digunakan sebagai pusat luminesensi untuk aplikasi fotosensor emisi hijau.

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Fabrication complex of Tb[EO4-Pic] into microparticle size with reprecipitation-evaporation method has been studied, where EO4 = tetraethylene glycol, Pic = picrate anion. For comparison purpose, the In situ method was also investigated. The result of the Tb[EO4-Pic] microparticle complex was dispersed into polymethylmethaacrylate (PMMA) polymer matrix to be a composite Tb[EO4-Pic]/PMMA. The composite is coated to substrate by using spin-coating technique. In this research is also studied the effect of polymer and substrates to the luminescence property of the Tb[EO4-Pic] microparticle complex and its composite. Particle size and fluorescence of the Tb[EO4-Pic] microparticle complex and its composite were carried out by Particle Size Analyzer and spectrofluorometer, respectively. The particle composite that prepared by reprecipitation-evaporation method is smaller (191.0 nm) than that in the In situ method (431.8 nm). The hypersensitive peak at 548 nm (5D4 à 7F5 transition) is character of the terbium(III) ion increased with increasing intensity ratio of the 5D4 à 7F5 / 5D4 à 7F6 transitions from 9.31 to 11.87 due to the polymer and increasing intensity ratio from 7.38 to 48.50 due to the composite coating on aluminum substrate rough surface. Microparticle complex of Tb[EO4-Pic] and its composite can be applied as luminescent center in photosensor application for green emission."