Papers by Author: Pisutti Dararutana

Abstract: It is well-known that silica sand is a special type of quartz sand that is suitable for glass fabrication due to its high silica content and low content of iron oxide. In this work, chemical analysis has been carried out on a sand sample from the Nong Phok site, Roi Et province, northeastern Thailand. The geological resources show that this site possesses a surface-to-near surface sand deposit. The grain of fine white sand consists of clear crystals. The grain shape is mainly angular-to-round. Chemical analysis shows that the sand contains more than 99 wt% silica and small amounts of Al, Ca, Ti, and Zr which is in agreement with international standards for glass production. The sand has been used as raw material for the fabrication of soda-lime, lead crystal, and lead-free high refractive index glasses. The colorless and various colored glass products have been satisfactorily used in domestic art and glass manufacturers which promotes local employment and economics.

Abstract: The blast that caused from terrorist activities, explosion and weapons effect on not only the human life, but also the architectural structure. The development of materials used to protect them is needed. Polyurea is a one type of elastomer that derive from the reaction product of an isocyanate component and a synthetic resin blend component through step-growth polymerization. It is revealed that polyurea is a new entrant in the field of elastomer has received enormous attention in view of its excellent blast mitigation properties and ballistic protection. In this work, the microstructure and elemental composition of polyurea samples are studied using scanning electron microscope coupled with energy dispersive X-ray spectrometer (SEM-EDS). The main composition consisted of carbon, oxygen and silica approximately 63-75, 17-29, and 0.15-1.69 wt%, respectively. Sulfur and chlorine present as the chain extender. Titanium is added to modify its structure. Other elements present as the additives, fillers and pigments. Atomic force microscopy (AFM) is conducted to confirm nano-scale composition. Dynamic mechanical, thermal and tensile properties are also studied. It is shown that the modulus and loss factor increase as the increasing of the frequency and temperature. The elongation capacity is greater than 100%. Infrared spectroscopy based on synchrotron radiation (SR IR) shows the various constituents of the composition in the form of the functional groups along with the wave number.

Abstract: t was known that historical objects were highly heterogeneous. Due to the complex nature of materials and objects, extremely sensitive, spatially resolved, multi-elemental and versatile analytical instruments were needed. The techniques employed should be as a noninvasive as possible and able to give complementary information from macroscopic to nanometer scales. In this work, X-ray based spectroscopy including energy dispersive X-ray fluorescence spectroscopy (EDS), Proton-induced X-ray emission spectroscopy (PIXE), and micro-beam X-ray fluorescence spectroscopy (µ-XRF) were used to analyze chemical composition of the Lanna-style glass. Microstructure was also studied. It can be concluded that these techniques in combination are powerful for the investigation of heterogeneous glassy materials.

Abstract: The study of the first alkali silica reaction (ASR) case in Thailand was conducted on fluoresced gel under UV light technique. It was done on ten random cored samples from different cracked structures of ten year-aged project and the other three cored samples from no-crack structure of one building and two bridges, ages older than 40 years. It was study on areas of suspected ASR gel in the interface zone (ITZ), aggregates and paste in the vicinity. The results of reflected area indicated the evidence of ASR gel at aggregate’s rim and the nearly areas as well as in some cracks in the matrix of 9 in 11 samples of the first set. The amount of reactive coarse aggregates was found in the range of 5-90% of total coarse aggregate content, which was supported by the expansion results of same cored samples from previous study. The results of this study indicated that the fluoresced gel technique provided the satisfied results which confirmed the accelerated expansion test from previous study. They can be used as an effective means for ASR screening test of existing structures both in the field and in laboratory.

Abstract: The Thai amulets that created in an image of Lord Buddha meditation were made to explain the Dharma of Buddha and believed to bless every life in this world for good karma. Phra Somdej Wat Rakhang amulet is the top of the five most famous Thai amulets. There are many molds with various compositions. In this work, it was the first time that X-ray fluorescence spectrometry methods; scanning electron microscope cooperated with energy dispersive X-ray fluorescence spectrometer (SEM/EDS) and particle induced X-ray emission spectroscopy (PIXE) were carried out to analyze their compositions. Two samples were collected from different molds. Results revealed C, Ca and Si were main composition. The differences in their compositions have been used to identify and characterize for each molds.

Abstract: Glasses have been used as decorative objects in Thailand for several hundred years. Decorative glasses can generally be seen as architectural components in old styled palaces and Buddhist objects. There were various colors ranging from transparent to amber, blue, green and red with different shades among glass of different colors. Fragments of archaeological glass samples were characterized for the first time using Raman microscopy with the aim of obtaining information that would lead to identification of the glass samples by means of laser scattering. The samples were also investigated using other techniques, such as particle induced X-ray emission spectroscopy and scanning electron microscope operated with energy dispersive X-ray fluorescence spectrometer. They were mostly lead-silica based glasses. The colors resulted from metal ions. The difference in chemical composition was confirmed by Raman signature spectra.

Abstract: Ecological crystal glass with no toxic compounds, especially lead, was based on soda-lime-silica glass that fabricated mainly from 50 wt% local dressing sand, 22 wt% barium carbonate and doped with various concentrations of zirconium dioxide. Density (ρ), refractive index (RI), thermal expansion coefficient (CoE) and hardness (HV) were measured. It was found that the values of ρ, RI and HV increased linearly as the increasing of zirconium dioxide contents, whereas the CoE was decreased. This type of glass was ecologically friendly material.

Abstract: Ecological glass with non-toxic was fabricated in bismuth-bearing glass using mainly local quartz sands and various concentration of bismuth oxide. The specific gravity (SG), refractive index (RI), thermal expansion coefficient (CoE) and hardness (HV) were determined. It was found that the values of SG, RI and HV were increased linearly as the increasing of bismuth oxide, whiles that of CoE was decreased. This glass is environmentally friendly materials.

Abstract: The effect of varying the TiO2–content on the lead-free high refractive index glass based on 25 wt% barium carbonate added in replacing lead oxide was prepared and its physical, optical, and electrical properties were investigated. Seven glass samples were synthesized and characterized by using an analytical balance, a refractometer, a LCR meter and an X-ray diffractometer. Specific gravity, refractive index, and dielectric constant increased linearly as the increasing of the TiO2-content. The amorphous state of modification of glass structure due to TiO2 addition was confirmed.

Abstract: Barium-bearing glass samples were fabricated using raw material from the beneficiation of local resource. Nd₂O₃ was added in various concentrations. Dielectric constant, density, refractive index, and absorption spectra of the glass samples were measured. It was found that the densities and refractive indices increased with increasing Nd₂O₃ contents. The dielectric constant and absorption spectra were plotted and discussed.