จำนวน Repository ( 5 )

การเตรียม การตรวจสอบคุณลักษณะ และศึกษาการปลดปล่อยยาปฏิชีวนะด้วยจีโอโพลิเมอร์
การเตรียม การตรวจสอบคุณลักษณะ และศึกษาการปลดปล่อยยาปฏิชีวนะด้วยจีโอโพลิเมอร์

The aims of this study were developed geopolymer matrix for controlled release amoxicillin antibiotic drug in the in vitro gastric and intestines (pH 1 and pH 6.8 temperature 37 ºC conditions). Three formulations of geopolymer tablets (GeAmSF5 GeAmSF7.5 and GeAmSF10) which different silica fume content were used in this study. Geopolymer tablets were measured compressive strength and characterized by using 3D laser microscope Scanning electron microscope (SEM) X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The amoxicillin release was analyzed by UV-VIS spectrophotometer. It was found that amoxicillin in geopolymer tablet was more resistance with various extraction solvents (ethanol water 50 oC pH 1 and 12 solutions) than amoxicillin commercial tablet in 2 hours. Moreover the amoxicillin constantly release from geopolymer matrix after 3 hours in both in vitro gastric and intestines. However amoxicillin was more release in gastric than intestines condition due to the strong acid leached aluminum ion causing damages geopolymer structure. Mathematical modeling of amoxicillin release from geopolymer matrix was fitted best with Higuchi model indicating diffusion of the drug out of matrix.

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การพัฒนาวัสดุจีโอโพลีเมอร์จากเถ้าแกลบและเถ้าชานอ้อย
การพัฒนาวัสดุจีโอโพลีเมอร์จากเถ้าแกลบและเถ้าชานอ้อย

This research studies the potential for using waste ash from industrial and agricultural by–products as a geopolymer material. This paper presents a study of the resistance to chloride penetration and resistance to sulfuric acid of geopolymer mortar containing ground rice husk ash (RA) and ground bagasse ash (BA). Geopolymer mortars with constant liquid to ash ratio and similar flow were used for the tests. Compressive strength porosity chloride penetration test Rapid migration test of chloride depth chloride ion diffusion coefficient immersion test of chloride depth and weight loss with impressed sulfuric acid were investigated. Test results show that the workable flow of geopolymer mortar was in the range of 110–115% and was dependent on the ratio by mass of sodium silicate to NaOH and the concentration of NaOH. Extra water was used to improve the workabililty. In case of rice husk ash geopolymer mortar the geopolymer mortars with high strengths were obtained with concentration of NaOH of 15M with the sodium silicate to NaOH ratio by weight of 2.5. However the bagasee ash geopolymer mortars with high strengths were obtained with concentration of NaOH of 10M with the sodium silicate to NaOH ratio by weight of 2.5. The use of rice husk ash and bagasse ash produces geopolymer mixes with good strength and resistance to acid and chloride penetration. The resistance to acid and chloride penetration is higher with an increase in the sodium silicate to NaOH ratio by weight of 2.5.

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Influence of Plasma Treatment on the Flexural Properties of Geopolymer Composites
Influence of Plasma Treatment on the Flexural Properties of Geopolymer Composites

In recently years geopolymer or polysialate composites have been developed and applied for a variety of fields. They are known as inorganic matrices composites which are fabricated and cured at room temperature or thermoseted in a simple autoclave. Geopolymer composites provide an excellent opportunity for achieving the goal of producing low cost high temperature resistant composite. The aim of this study is an investigation and comparing the flexural properties of geopolymer composites after reinforcements were influenced by plasma treatment with original fibre fabric. And preliminary results of the improvement in tensile strength Young’s modulus elongation of E-glass fibre fabric due to plasma treatment are studied in this paper. Many reinforcements and geopolymer matrices are now available but our works are focused on geopolymer composite Q17 Q13K-1 combination with E-glass fibre fabric which was investigated fabrication procedures together with their specific properties of these materials have been evaluated compared and discussed.

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Mechanical Properties of Silica-Based Geopolymer Composites Cured at Ambient Conditions in Accordance with Size-Independent Method
Mechanical Properties of Silica-Based Geopolymer Composites Cured at Ambient Conditions in Accordance with Size-Independent Method

In this paper silica-based geopolymer matrix reinforced composites containing approximately 35 50 or 55 wt.% of carbon (HTS 5631 1600tex 24K TohoTenax) advanced basalt (BCF13-2520tex KV12 Int Basaltex) or electrical grade glass (E-glass: E2400P192 Saint-Gobain Vetrotex) roving fibers respectively were synthesized and fabricated at ambient conditions. The flexural properties of the resulting composites which are high toughness: the shear stress plays here a greater role in compared with other ceramic matrix composites were determined on a universal testing machine under three-point bending mode in accordance with novel size-independent method which based on testing specimens at different scale of sample height (H) to span length (L) ratios; The basic principles of the new size-independent approach are presented as well. Microstructures of composites were analyzed by means of scanning electron microscope (SEM) on perpendicular sections the images show the adhesion between the fibers and geopolymer matrix are very good and micro-cracks on both cross-sections and surfaces of geocomposites are determined as inborn defects of inorganic matrix composites.

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