3.7 SPRAY PYROLYSIS TECHNIQUE
Spray pyrolysis technique consists of temperature controller, spray gun, substrate heater, a thermocouple and a compressor unit. The proper pressure of compressed air was used in order to spray the solution on to the substrate which is kept on the substrate heater. The temperature of the substrate is controlled by the temperature controller via thermocouple. Fig. 3.7 A typical spray pyrolysis system
The solution of the precursor is kept in a solution reservoir and the solution can be carried through a spray gun to spray on the substrate. Prior to the film deposition processes by spray pyrolysis one needs a solution of required material. The molarity (M) of solution is being optimized by making solution of different molarities followed by several characterizations. A typical spray pyrolysis system is shown in Fig. 3.7.
3.7.1 Principle and thin film formation mechanism
This technique involves spraying a solution containing soluble salts of the constituent atoms of the desired compound on to a hot substrate maintained at temperatures generally in the range of 300- 500 oC. The hot substrate
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It is a jet effect; as with a funnel velocity of the fluid increases as the cross sectional area decreases, with the static pressure correspondingly decreasing. When a fluid flows through a tube that narrows to a smaller diameter, the partial restriction causes a higher pressure at the inlet than that at the narrow end. According to the laws governing fluid dynamics, a fluid's velocity must increase as it passes through a constriction to satisfy the principle of continuity, while its pressure must decrease to satisfy the principle of conservation of mechanical energy. Thus any gain in kinetic energy of a fluid may accrue due to its increased velocity through a constriction is negated by a drop in
Using the scopula, take a small amount of the substance and add it to the spot plate. Add deionized water to the section with the substance. Stir to see if the substance dissolves or not. Record your observations.
But here we discuss only Chemical Vapor Deposition which helps for mass production of CNTs. The process discussed in this article is otherwise a mimicking of the Chemical Vapor Deposition.
method, and the Nazi dope (lithium or sodium reduction). The P2P method is less common
The purpose of this lab was to understand the relationship between emission spectra and atomic structure using small samples of 7 chloride salts of different metals. Emission spectra(or line spectra) is a collection of wavelengths representing different energies. Electrons in an atom occupy different energy levels and are in the ground state when they are at a low energy level. When they start to enter a higher energy level after gaining energy, they start to enter their excited state. Once in their excited state, they proceed to go back to their respective energy level by emitting light in the form of a
Bernoulli’s principle is the concept that as the speed of a moving fluid (liquid or gas) increases, the pressure within that fluid decreases. This principle was originally formulated in 1738 by the Swiss mathematician and physicist Daniel Bernoulli, it states that the total energy in a steadily flowing ...
Investigation of the heat energy produced by combustion of various alcohols. Aim: ---- To investigate how different alcohols produce different amounts of heat energy through combustion. I will be heating water using different alcohols as fuels and measuring the amount of fuel consumed.
water has risen to 60°c I will then put the lid on the spirit burner
...roved hardness, strength and wear resistance are achieved [12, 13]. The coated material (CSZ) can be applied as thermal barriers, having high temperature resistance. These coatings permit higher operating temperatures by controlling the thermal subjection of structural components. There as increase in part life by controlling oxidation and thermal fatigue [14]. The thermal resistance characteristics of the surface coating basically depend on the following parameters. Distance between spray nozzle and substrate, flow rate of the precursor solution, post heat treatment temperature and duration of heat treatment [15-17]. The required thermal energy varies for different materials and solvents used in the spray process. The atomization of the spray solution, into a spray of fine droplets also depends on the geometry of the spraying nozzle and pressure of a carrier gas
Investigating Factors Affecting the Heat of Combustion of Alcohols PLANNING SECTION Introduction ------------ Alcohols are organic substances, and consist of Hydrogen, Oxygen and Carbon. All alcohols are toxic but the amount that can be tolerated by the human body varies for different alcohols. For example drinking small amounts of Methanol can lead to blindness and even death.
- The amount of times the mixture was stirred. We stirred the mixture until the Ammonium Nitrate was dissolved, so the amount of times we stirred after each teaspoon was different.
This is a great discovery of Bernoulli. It seems to make sense when we apply it to blood vessels. Where the blood moves faster, the more it pushes forward, the less it pushes on the walls. A later more ingenious application for this idea is flying. The airplane was invented after Bernoulli but not due to him. The airplane and Bernoulli’s equation
The mixture was then allows to cool and the excess zinc to settle. While still hot the solution was decanted into stirred cold water (200 mL) precipitating the crude product. The zinc residue was washed with warm glacial acetic acid (2 x 5 mL) and this was added to the aqueous solution.
Therefore, the relationship between pressure drop and boil-up rate means that more volume of vapour educed per unit time results in more restriction of the holes in the sieve tray and that caused by passing of vapour through the liquid on top of the tray. Hence, the higher the velocity, the higher the boil-up rate and so does the overall pressure drop.
Third, the liquid will enter to the expansion valve with the higher pressure and leaves with the low pressure.
With reference to Eq. (1), ∆V/∆T refers to the rate of fluid volume flow, while A refers to the cross-sectional area and V the fluid velocity at points 1 and 2 in a tube respectively. From Eq. (1), it can be seen that as the rate of fluid volume flow is assumed to be constant for an incompressible fluid, a decrease in the cross-sectional area of a tube would lead to an increase in the fluid velocity passing through it3.