Kanokthip Boonyarattanakalin

Active Ilmenite Surface Structure Influence of Acid Assisted Ball Milling

Active-ilmenite powder derived from natural ilmenite sand was prepared by the ball milling process with acid-solution and Deionized (DI) water. Morphology and particle size of active-ilmenite product in acid/DI-assisted ball milling process were monitored by field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Surface atomic component and chemical bonding were investigated by X-ray photoelectron spectroscopy (XPS). Meanwhile, bulk chemical oxidation and fine structure of active-ilmenite were studied by X-ray absorption near edge structure (XANES) and extended X-ray absorption ne-structure spectroscopy (EXAFS) to confirm the oxidation state and local active species structure at surface. Active-ilmenite by acid-assisted ball milling process is a distinctive method for the preparation of active-ilmenite product with high active surface. Moreover, the distortion of TiO6 and FeO6 octahedral cluster on the sample surface was detected in all milled samples with acid-assisted ball milling process. The presence of Fe2+, Fe3+ ions and miniature sulfate was also detected on the sample surface by milled product with acid-assisted method.

Extraction and characterization of nanocellulose from sugarcane bagasse by ball-milling-assisted acid hydrolysis

This study is proposed to characterize nanocellulose extracted from sugarcane bagasse (SCB). For extracting cellulose, the bagasse was treated by chemical treatment. The nanocellulose was prepared using ball-milling with acid hydrolysis. Morphology of bagasse, cellulose and nanocellulose were characterized by scanning electron microscopy (SEM). The chemical composition of extracted cellulose and nanocellulose was investigated by Fourier-transformed infrared spectroscopy that verifying the removal of lignin and hemicellulose during cellulose isolation process from sugarcane bagasse. The crystalline structure of cellulose and nanocellulose were characterized by X-ray diffraction (XRD), indicating that the nanocellulose prepared by ball milling with acid hydrolysis has higher crystallinity than nanocellulose prepared only ball milling.This study is proposed to characterize nanocellulose extracted from sugarcane bagasse (SCB). For extracting cellulose, the bagasse was treated by chemical treatment. The nanocellulose was prepared using ball-milling with acid hydrolysis. Morphology of bagasse, cellulose and nanocellulose were characterized by scanning electron microscopy (SEM). The chemical composition of extracted cellulose and nanocellulose was investigated by Fourier-transformed infrared spectroscopy that verifying the removal of lignin and hemicellulose during cellulose isolation process from sugarcane bagasse. The crystalline structure of cellulose and nanocellulose were characterized by X-ray diffraction (XRD), indicating that the nanocellulose prepared by ball milling with acid hydrolysis has higher crystallinity than nanocellulose prepared only ball milling.

Effects of Seeding Layer Annealing Temperature on Physical and Morphological Structure of Ga/F Co-Doped ZnO Nanostructures

In this work, effects of annealing temperature of seeding layer on structural properties and morphologies of Ga/F co-doped ZnO nanostructures synthesized by hydrothermal process were investigated by varying the annealing temperature of seed layer as 300-500 °C. The ZnO seeding layers were deposited onto cleaned glass substrates by dip-coating technique using zinc acetate dehydrate (CH3COO)2Zn·2H2O as starting coating precursor. The Ga/F co-doped ZnO nanostructures were then grown on these seed layers by conventional hydrothermal process using Zn(NO3)2, NH4F, GaN3O9 and hexamethyltetramine as Zn, F and Ga sources, respectively. Effect of seed layer annealing temperature on morphologies, structural and Photoluminescence properties was investigated by X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM), and Photoluminescence spectra, respectively. Variation of annealing temperature of seed layers can significantly result to the difference in morphological, structure and shape of the as-synthesized nanostructure products. It is found that the increase in annealing temperature leads to alternation in their shape from vertically-aligned nanosheets to nanorods with their average size ranging from 50 to 200 nm. Furthermore, the luminescence could be ascribed to the different contributions of the defect emissions, such asthe increase in the oxygen vacancy (VO) emissionor the decrease of the Zinc vacancy (Vzn). However, it can be speculated from the photoluminescence that the incorporated Ga and F substitute into ZnO.