Questions On Phase Changes Materials

The phase diagram is a simulator representing how much pressure can be added and the different forms of your substance (whether it's liquid, solid or gas.) in different environments and put to observation tests. The three regions are solid, liquid and gas. Gas when heated spreads everywhere and moves rapidly. When gas is frozen it falls to the bottom and gets stuck together as if it was a solid or a liquid. Liquid when heated boils, then turns into gas and builds up pressure. Eventually enough pressure to blow the lid off. Liquid when frozen turns into a solid. Solids when heated turns into a liquid, then soon evaporates and becomes a gas. When a solid is frozen it stays as a solid.

High levels of emulsifier are then added to maintain a separated suspension during the aqueous phase. A stable dispersion is formed in the SAN phase after the polybutadiene is partially grafted. The latex particles are then extracted through a coagulation process and produce an ABS concentrate. After the compounding process, ABS polymers are produced. The advantages of the emulsion process are that the resultant ABS resins are more flexible and they can have different hardness, resistance and tensile strength depending on the different combinations of monomer ratios. However, residual monomers and solvents will make

[4] Engineeringtoolbox.com, 'Thermal Conductivity of some common Materials and Gases', 2015. [Online]. Available: http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html. [Accessed: 20- Jul- 2015].

It was hypothesised that the foam would be the most effective insulating material. After testing each of the variables twice and calculating the averages and rates, the hypothesis was supported by the data collected. It was hypothesised that foam would be the best insulator because of the material’s dense properties and the air pockets in the foam that can absorb heat molecules. The hypothesis was supported as foam contains portions of air ‘bubbles’ that trap heat in the process of convection, and can therefore contain the heat without considerable amounts of heat discharging. The controlled variable was the least effective insulator as the heat was able emit through the process of convection which can only occur in liquids and gases, such as air.

BPA is one of the highest produced synthetic chemicals used in industry since 1960’s [1]. It is a white solid essentially used in the production of polycarbonates and epoxy resins. Polycarbonates and Epoxy resins are widely used as they make lives more comfortable and easier. Owing to their advantages such as high impact strength, exceptional clarity etc., they exist everywhere ranging from reusable cups to bullet proof windows and compact discs [5].

Determining the percent recovery of the sample indicates the efficiency of the recrystallization and sublimation processes (“Experiment 2: Purification…”, n.d.). It also indicates the purity of the sample; a higher percent recovery implies a low concentration of impurities, while a lower percent recovery implies the opposite (GlaxoSmithKline, 2013). In the recrystallization of naphthalene, the high percent recovery of naphthalene after the purification is an indication that less impurities are present in the initial sample. In the sublimation process, caffeine recovery is 10.94%. The low recovery percentage indicates a higher concentration of impurities in the initial sample. During the preparation of the caffeine sample, pencil was used in

Since glaciers are melting, many organisms are being affected. Since glaciers are melting, the habitat of polar bears, walruses, arctic foxes, and other arctic animals are being destroyed, leading to theses animals’ extinction. Glacial melting leads to a rise in sea levels, which gives land animals less land to live on. Glacial melting has been going on forever because glaciers are always building up and retreating, but glacial melting started to get worse around the 1800s, when the production of trains and factories was big. Glacial melting affects arctic animals, sea levels, and potable, drinkable, water.

PMMA is routinely delivered by emulsion polymerization, arrangement polymerization, and mass polymerization. By and large, radical start is utilized (counting living polymerization strategies), yet anionic polymerization of PMMA can likewise be performed. To deliver 1 kg (2.2 lb) of PMMA, around 2 kg (4.4 lb) of petroleum is required. PMMA produced by radical polymerization (all business PMMA) is a tactic and totally nebulous.

The swelling agent used in this case is 1,2,3-Trimethyl benzene and the mineralizing agent is ammonium fluoride. The silica source used is tetra ortho silicate (TEOS) and these mixture is used in acidic conditions. In this method the surfactant P-123 was diluted by a strong acid i.e. 1.6M HCL and was stirred in a stirrer for 1 hour at 40oC followed by the addition of swelling agent and the mineralizing and this mixture was further stirred for 20 hours under the same condition. Then the silica source i.e. TEOS was added and this mixture was stirred for another 24 hours under the same operating condition and the solid that was obtained at the end of the process was then filtered, then washed with de-ionized water followed by calcination at 500oC for another 8 hours to remove the organic component. Hence, MCF silica was

(Figures 6h, i). The roles of porous sponge layers can be understood as the relaxing bending strain of the deposited metals and inducing efficient adhesion of metals on polymer films (Figure 6e).

Chemistry: Melting points were obtained with an Electro thermal digital melting point apparatus (model 9100) and are uncorrected. IR spectra (KBr) were measured on Perkin-Elemer FT/IR spectrophotometer, 1H-NMR spectra were recorded on JEOL (500 MHz) at Faculty of Science, Alexandria University in DMSO-d6 as solvent, using tetramethyl silane (TMS) as internal reference. Elemental analysis (C, H, and N) and Mass spectra were performed at the Micro analytical Unit of Cairo University using a Vario III CHN analyzer and DI analysis Shimadzu QP-2010 plus mass spectrometer, respectively. The chemical reagents used are Aldrich and BDH.

Emulsion polymerization technology is widely applied in many fields including synthetic rubber, thermoplastics, coating, adhesive, and plastic modifier [1–4]. Much of the interest in it derives from the possibilities for the preparation of monodisperse or functional latex particles [5,6]. Until today, the challenges

The days of doing research to improve mechanical and thermal like basic properties by adding nanofillers, surface modified long fibers, developing polymer blend system are becoming regular activities for manufacturers. The innovation need and ongoing research in polymeric materials are multi-functional and highly value creating for new product innovation, which can lead a new business and market growth. For example, recent past years, LED bulb market has seen significant growth, due to low cost manufacturing and highly energy

Solidification is process through which crystalline materials, such as metals and alloys, transform from non-crystallized state into crystallized state. This process is a basic technique used in alloy casting, growth of single-phase semiconductors, welding and etc. We need to understand what’s happening during solidification and how it affect the structure of final materials, which directly determines the properties of products. Besides, a proper set of solidification parameters also helps to improve energy efficiency.

The main aim of investigation is to develop new nano based PCMs (phase change materials) establishing thermal energy storage for catering cooling needs in tropical buildings. PCMs lag with their thermal properties like thermal conductivity, latent heat of capacity etc. To enhance its properties generally nanoparticles are dispersed in PCMs. The present work deals with synthesis of TiO2 nano particles using sol-gel chemical method and characterizing particle size, shape and its morphology. The as prepared TiO2 nano particles were dispersed with different wt. % in Rubitherm 21 type PCM. Then, nano based PCMs were tested for its melting, freezing, latent heat characteristics and concluding for compact ability with building applications to