จำนวน Repository ( 3 )

ผลของเส้นใยธรรมชาติและการปรับปรุงผิวที่มีต่อสมบัติทางความร้อนและกายภาพของพอลิแลคติกแอซิด
ผลของเส้นใยธรรมชาติและการปรับปรุงผิวที่มีต่อสมบัติทางความร้อนและกายภาพของพอลิแลคติกแอซิด

his research work aimed to study the effects of the addition of sisal fiber and surface treatment by epoxy silane on the physical and thermal properties of polylactic acid (PLA). Specimens of PLA and unidirectional fiber-reinforced composite were processed by a compression molding machine and evaluated the physical and thermal properties by water absorption measurement and differential scanning calorimetry (DSC) analysis respectively. The result showed that water absorption tended to increase by adding sisal fiber whereas surface treatment of sisal fiber by epoxy silane improved water resistance of composites. The water absorption values at immersion time of 5 days were 0.89 1.13 and 1.26 % for PLA PLA/treated sisal fiber composite and PLA/untreated sisal fiber composite respectively. For thermal properties the addition of sisal fiber led to decreases in glass transition temperature and crystallinity. These were because the presence of continuous fiber might interfere with the crystallization of PLA. The surface treatment of continuous fiber with epoxy silane led to difficult crystallization. The good interfacial adhesion interrupted PLA alignment.

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การดูดซับสารละลายโครเมียม (III) ด้วยแคลเซียมไฮดรอกซีอะพาไทต์
การดูดซับสารละลายโครเมียม (III) ด้วยแคลเซียมไฮดรอกซีอะพาไทต์

Chromium (III) is an inorganic salt being used as corrosion inhibitor plating agents surface treating agents furniture furnishings and textile printing and etc. The discharge of industrial waste water containing chromium (III) into the water source was toxic to the aquatic lives and some parts accumulate in the soil chromium (III) reduces the growth of plants reduced photosynthesis inhibit the enzyme activity imbalanced in plants and reduced productivity and etc. For this reason method to remove it before discharge the effluent into the water source is necessary. The use of apatite materials for adsorption and immobilization of various pollutants was a technique that was more likely to be used.Due to its high adsorbency easy to use and environmentally friendly. The purpose of this research was to study the preparation of calcium hydroxyapatite structural characterization of calcium hydroxyapatite by X-ray diffraction technique adsorption study of chromium solution with calcium hydroxyapatite in various conditions and the determination of adsorption isotherm. The results showed that the optimum contact time of calcium hydroxyapatite and chromium solution was 3 hours. Most adsorption works well at a pH of around 6.76. Considering the amount of chromium (III) adsorbed at equilibrium (q) it was found that the calcium hydroxyapatite with 10 % zinc added that has been calcined to 400 OC and the calcium hydroxyapatite with 15 % zinc added that has been calcined to 800 OC were to adsorb chromium (III) more than other sorbents. The adsorption isotherm was suited with Fruendlich and Langmuir. The calcium hydroxyapatite with 10 % and 15 % zinc added that has been calcined to 400 OC had the highest adsorption capacity (qm) up to 178.57 and 181.82 mg/g respectively. In addition it was found that calcium hydroxyapatite which heated to 800 degrees Celsius can decompose tricalciumphosphate.

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การดูดซับสีย้อมเมทิลีนบลูบนถ่านกัมมันต์ที่เตรียมจากกากน้ำตาลโดยวิธีการกระตุ้นด้วยสารเคมีและไมโครเวฟ
การดูดซับสีย้อมเมทิลีนบลูบนถ่านกัมมันต์ที่เตรียมจากกากน้ำตาลโดยวิธีการกระตุ้นด้วยสารเคมีและไมโครเวฟ

This research aims to produce activated carbon from molasses via a chemical activation process with potassium hydroxide (KOH) and a microwave heating process which consumes less energy and provides more rapid and uniform heat distribution than a conventional heating. The obtained activated carbon was then characterized with BET SEM and FTIR. It exhibited a large specific surface area of 1631 m2/g and a total pore volume of 1.124 cm3/g consisting of mesopore and micropore. In addition the active functional groups were also found on the surface of the activated carbon. Thus it was brought for the adsorption test with methylene blue. It was found that the adsorption capacity of the activated carbon increased with time and reached the equilibrium within 8 hours. The adsorption data of the activated carbon were corresponded to Langmuir isotherm with the highest adsorption capacity of 370.37 mg/g. The adsorption kinetic of the activated carbon exhibited pseudo-second order reaction suggesting to the chemisorption phenomenon. From the thermodynamic study it revealed that the adsorption process were endothermic and spontaneous reactions.

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