Dr. Salma Abdelghaffar Hassan Alamin1, Dr. Alawia Abdalla ELawad2, Prof. Imad-eldin Ahmed Ali Babiker3, Dr.Osman Mirghani Mohamed Ali4
1. Environmental and Natural Resources and Desertification Research Institute (ENRDRI) Corresponding author.
2. Alnelaneen University.
3. Agriculture Research Cooperation (A R C).
4. University of Khartoum.
Khartoum Refinery (KR) is located north of Khartoum State.Water samples were collected in clean containers after treatment. Physical and chemical properties of treated water in the area were investigated. The pH and electric conductivity (EC) were measured using a pH meter and a conductivity meter, respectively. Percentage amount of oil and grease was measured using oil and extraction method with Soxlet apparatus. The concentrations of metal elements of the water, samples were measured using an atomic spectrophotometer.
Results showed that the treated waste water at Khartoum Refinery was strongly alkaline (pH 9.7) electric conductivity (4.7 dS/m) and oil and grease of 1.6 mg/L. The chemical analysis of treated water revealed the presence in meq/l of Mg (26.1), Ca (18), Na (222.6), K (4.98), Fe (0.017), Cu (0.0063), Zn (0.024), Mn (0.0146) and Co while Cd and Cr were trace to nill.
Pages: 121 – 125 | Full PDF Paper
Influence of Solvents on Characteristics of Inkjet Printing Conductive Ink Based on Nano Silver Particles
Chien Mau Dang, Khanh Kim Huynh and Dung My Thi Dang
Institute for Nanotechnology, Vietnam National University-Ho Chi Minh City, Community 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam.
Abstract: Solvents are used in ink as diluents to control the rheological properties of the ink such as viscosity, surface tension, contact angle, flow and leveling properties and evaporation rate. The solvents are used to keep the ink in liquid form when applied to the printing plate or cylinder from cartridge until transferred onto the substrate surface to be printed. In this study, silver nanoparticles were synthesized by reduction of silver nitrate in ethylene glycol under ultrasonic wave. The silver nanoparticles-based ink was prepared by dispersing silver nanoparticles in the mixture of different organic solvents. The inks were characterized by using Ultraviolet-visible spectrophotometry (UV-Vis), particle size analyzer (DLS), surface tension and contact angle measurement. The surface of the printed silver layers was observed by 3D optical profilometry microscope. Modification of the solvent led to changes in the surface tension and the contact angle of the ink. This affected the printing process, the evaporation rate of solvent and the presence of coffee ring effect. The role of the solvents was examined to prevent this effect. The main purpose of this study was to prevent coffee ring effect of the silver nanoparticles ink and to improve the quality of printed patterns in inkjet printing process.
Keywords: Silver nanoparticles, solvents, coffee ring effect, rheological properties.
Pages: 126 – 134 | Full PDF Paper