จำนวน Repository ( 4 )
การสังเคราะห์อนุภาคนาโนโลหะโดยการระเหยด้วยเลเซอร์ในน้ำ
Nanomaterials are widely used in many applications such as medicine cosmetic industry and other. When the size of the particle is reduced the number of atoms on the surface and the ratio between surface area to volume of the material increase result in the enhancement of the material’s physical magnetic and optical properties. There are many methods to synthesize the nanoparticle such as grinding chemical reaction electrochemical method and laser ablation. In this research laser ablation was chosen to synthesize the metal nanoparticles because this method is quick and convenient and does not produce hazardous waste. The results show that the laser with 6V electric potential could synthesize the metal nanoparticles with the smallest size. The metal nanoparticles with larger size were obtained when higher electrical potential of 8V and 10V were used. In conclusion the electric potential of the laser affects the size of the metal nanoparticle obtained from laser ablation.
การเตรียมและศึกษาสมบัติทางโครงสร้างและแม่เหล็กของอนุภาคคอมโพสิตระดับนาโนเมตรของไฮดรอกซีอะพาไทต์และซิงก์เฟอไรท์ เพื่อประยุกต์ใช้ในการรักษามะเร็งในอนาคต
A promising composite of zinc ferrite (ZnFe2O4) and bioactive hydroxyapatite (Ca10(PO4)6(OH)2 ;HAp) has expected to potential for future bone reinforcing formation. In present study zinc ferrite and hydroxyapatite composite was prepared by solid state reaction route for easier control of structural and magnetic characteristics and with low cost. Hydroxyapatite powder was synthesized by precipitation method from chicken eggshell. Mixed powders with varying ZnFe2O4/HAp weight ratios from 2-10 wt% were milled together and uniaxially pressed and then sintered at 1200 oC for 3 hours. The XRD results showing no other phases of composite with only HAp and ZnFe2O4 phases were identified indicating high stability of HAp property. Phase fractions of ZnFe2O4 were found to increase from 10.8 to 18.73 wt% with increasing content of ZnFe2O4. FT-IR results of ZnFe2O4/HAp composite were only revealed vibration bands of standard HAp phase. This may due to the overlapping of the ZnFe2O4 vibrational bands with HAp bands. However their intense variations observed in HAp vibrational bands indicated the interaction between ZnFe2O4 and HAp. The surface morphology of these ZnFe2O4/HAp composite exhibited primary grain in nano scale with enhanced pore structure and Interconnectivity when ZnFe2O4 weight ratios increased; indicating high surface area for cell attachment and better good cell growth and differentiation. The higher saturation magnetization as well as higher super paramagnetic behavior could be easily altered by increasing ZnFe2O4 content in the composite.
Dispersion of copper oxide in water by pH value and ultrasonic method
The objective of this research is to study the dispersion of copper oxide particles in water using as a coolant in heat exchangers. Copper oxide particles were prepared by precipitate method. The parameters affected to dispersion of copper oxide were pH of solution and ultrasonic time. The results showed that an average crystalline size of copper oxide was in nano scale (< 22 nm). At pH value of 13 copper oxide was well dispersion in the water. Appropriate ultrasonic time of dispersion is dependent on particle sizes of copper oxide. The small particle sizes of copper oxide led to decreasing of ultrasonic time. On the other hand an increasing in particles sizes required longer ultrasonic time. Stability of suspension of CuO in the water decreased with an increasing of time. Moreover it was found that CuO particles were well dispersed in the water at pH value of 13 and ultrasonic time of 15 minutes
The Study and development of certain microorganisms with high capability in nanosilver particle biosynthesis
This research report is manipulated that summarized the moment of research project in the subject of “The Study and Development of Certain Microorganisms with High Capability in Nanosilver Particle Biosynthesis”. This project had been take time in 12 mounts. We focused on the isolation of microorganism that from manufacturing process and forming in gems and jewelry industry. Results showed that the initial silver refinery microorganism performed only in terms of Pseudomonas genus especially in AgNO3 solution. In contrast Bacillus genus was not clearly effective silver refinery. These results could be the basis information for establish and develop system for silver refinery and/or silver quality improvement with biological process especially microorganisms in future.