Using Polystyrene ( Ps ) Standards For Calibration Essay

In the modern world, it is near impossible to live in an environment where one is not exposed and reliant upon the use of polymers. From credit cards to nappies; plastic bottles to prescription glasses, the applications of polymers encompass an endless range of everyday necessities. However, the significance of synthetic polymers was not universally recognised until its initial introduction as polyethylene during World War II. During the combat, they served as a critical material for insulated radar electronics (ACC, 2005).

The poly(aniline-co-o-phenylenediamine) (ES) was synthesized by an in situ chemical oxidative copolymerization of aniline and o-phenylenediamine. At first, aniline and o-phenylenediamine monomers (5:1 in mass ratio, exactly 4.56 mL, 50 mmol aniline: 1.08 g, 10 mmol o-phenylenediamine) were dissolved in 5 mL conc HCl at room temperature under magnetic stirrer at 900 rpm. After that, 60 mL of potassium dichromate (initiator) which was separately dissolved in distilled water (K2Cr2O7 8.8 g / 250 mL distilled water) was slowly added into the reaction medium under the above conditions. Then, the reaction solution was kept for 24 hr at room temperature to complete the copolymerization reaction. Ammonia solution (5 mL of 33 % NH4OH diluted by 20 mL distilled water) was added drop wisely until a brown precipitate was formed which was collected by filtration using a Büchner funnel. The obtained precipitate [emeraldine base (EB), deprotonated form] was

30-33). Edexcel Limited. Jenkins, A., Kratochvíl, P., Stepto, R. F., & Suter, U. W. (2009). Glossary of Basic Terms in Polymer Science. Pure and Applied Chemistry , 68 (12), 2287-2311.

You will produce a report that justifies and evaluates the tools and frameworks that you used in completion of Assignment 1.

GPC Measurements were performed using a Waters 1515 Isocratic HPLC using tetrahydrofuran (THF) as an eluent at 35 °C, at a flow rate of 1.0 mL/min. The polymers were dissolved in THF at a concentration of 6 mg/mL. The system was calibrated using a series of monodisperse linear PPO standards with molecular weights in the range 200–12000 g/mol.

The results from this experiment provide insight on organic substances and how to use microscale science. In Part A of this experiment, the accuracy of microscale experimentation was shown through the weighing of liquids and calculating density. The calculations performed to determine the densities of the liquids were accurate. The density of water was calculated to be .94g/mL and the density of hexane was calculated to be .6g/ mL. A slight deviation was shown when the results were compared to literature values.

Abstract: Ion exchange chromatography is used to separate molecules base on their electrical charge and interpret the behavior of charged molecules in different samples. This is done by using a 2-step salt gradient, during the separation, molecules were released from the column base on how strong they are, the weaker substance was released first. While, in the gel filtration molecules are separated base on their size and shape using a matrix porous which allows larger molecules to be release in the beads more easily than smaller molecules.

properties has been investigated as well as acid stability. The new gels show that control over

This mixture was stirred for 1 h and evaporated overnight to obtain the investigated complex. This formed solid investigated complex was filtered, wash and then dried in vacuo over anhydrous CaCl2. TLC is used for determining the purity of investigated complex by using silica gel G

Before any tests were performed, a list of thirty-three compounds with their molecular weight, chemical formula and structure, and melting points was compiled. This list was used to compare with the results of our tests. Using Mel-Temp® device number 2 the melting point test was conducted as the first test. Approximately 3mm of the unknown was obtained using a capillary tube. This sample was placed in the center of the device and the device was turned on to setting four. When the sample first began to liquify and when the sample was completely melted the

The purpose of this experiment is to compare and contrast liquid volume reading values of different measuring devices, determining the precision and accuracy of experimental measurement. This was done through use of a graduated cylinder, a serological pipette, and a variable volume pipette.

After that, the column was washed with binding buffer (contains 20, 35 and 50mM imidazole perspectival, each five column volumes). The VHHs were eluted using linear gradient of imidazole (contains 100, 250 and 500mM imidazole perspectival, each two column volumes). Purified VHHs were desalted and concentrated by Amicon filter using 3kDa cut-off.

In order to study the stability and conformational changes of the free PR and above-mentioned complexes during MD simulation, Root mean square deviation (RMSD) analysis was calculated (Karami, Jalali, & Mirzaie, 2017b) for backbone atoms of both structures (Figure 11). As shown in Figure 11, it can be said that all systems enjoy a level of the RMSD between 0.100 – 0.415 nm during 100 ns MD simulation. It is obvious that the RMSD of the free PR gradually rises in first 3 ns; afterward, no tangible rise was seen in the RMSD rate of the free PR until the end of the simulation,

Decrease in glutaraldehyde cross-linker on increasing the polymer precursor might be happening due to the increased probability of colliding polymers and cross linking agent in this unfrozen liquid microphase where all chemical reactions take place. More probability of colliding might be decreasing the amount of glutaraldehyde required to crosslink polymers for gel synthesis. It was also observed that if the amount of glutaraldehyde used was more than the optimum concentrations (Table 1.1), the gel formed lack porous network and were tough and brittle. When the glutaraldehyde concentration was reduced and kept lower than the optimized one, the gels were weak in mechanical strength. This observation suggests that there seems to be some competition between the nucleation process which takes place in frozen regions and gelation process which takes place in unfrozen liquid microphase. When the concentration of glutaraldehyde was lower than optimum, nucleation process dominates the gelation process and the gels formed were weak due to large pores and less polymer wall formation by cross linking of polymers. When glutaraldehyde quantity was taken more than optimum, gelation dominates the nucleation process and the gels formed were without any pores and were brittle. Figure 1.1A shows the digital images of optimized gelatin sheets. Figure 1.1B and 1.1C shows that at an optimized polymer and cross-linker ratio

Povidones with K-values equal to or lower than 30 are manufactured by spray-drying and occur as spheres. Povidone K-90 and higher K-value povidones are manufactured by drum drying and occur as plates. The USP 28 describes povidone as a synthetic polymer consisting essentially of linear 1-vinyl-2-pyrrolidinone groups, the differing degree of polymerization of which results in polymers of various molecular weights. It is characterized by its viscosity in aqueous solution, relative to that of water, expressed as a K-value, in the range 10–120. The K-value is calculated using Fikentscher’s