Absorbance Spectra For Different Gamma Doses Of PVA / Ag Nannocomposite Films?

ABSTRACT: Copolymers of aniline and o-phenylenediamine / kaolinite composites were synthesized by 5:1 molar ratios of the respective monomers with different percentages of nanoclay via modified in situ chemical co-polymerization. The results were verified by measuring the FT-IR and UV-vis absorption spectra for PANI-o-PDA / kaolinite composites. The thermal behaviour of the copolymer and composites was studied. PANI-o-PDA / kaolinite composites were thermally more stable than pure copolymer. Surface morphology of copolymer composites was recorded at different magnification power by SEM which revealed whitish micrometric beads distributed all over the field with particle size in the range of 0.122 μm to 0.233 μm. This work demonstrates that

This concept can be explained using the term band gap, a property that is characteristic of semiconductors. The band gap can be defined as the difference in energy between the valence and conduction band and is typically in the range of 1-3 eV for semiconductors. In bulk materials the energy bands are a continuum of energy levels arising from the overlapping of the atomic orbital‘s due to the large number of molecules. When a semiconductor is brought to the Nano scale, containing lesser number of molecules, the quantized energy levels become distinct. Thus the addition or removal of atoms significantly changes the energy levels within the band making the band gap size dependent.

From the results, we can conclude that 0.9mM ONPG solution has the highest absorbance value and 0.1mM ONPG solution has the least absorbance. However, 1.0mM ONPG solution, which has the highest concentration, does not have the highest

Both natural and synthetic polymers are a vital part of our daily lives. Natural polymers are found in rubber, skin, hair etc. Synthetic polymers are found in nylon, polyester, plastic, chewing gum etc. This lab is demonstrating the properties of the common synthetic polymer polyvinyl alcohol (PVA). It is often used as a thickener or stabilizer cosmetics but also in paper cloths, films and cements.

Several attempts have been made to improve the properties of PLA. Researchers have approached surface modifications to enhance the mechanical properties, especially toughness, processability, degradation behaviour and crystallization11. By the use of surface modification techniques different reactive groups such as –COOH, -OH, and –NH2 can be introduced on the surface of PLA. Grafting technique was utilized by Spinella et al.12, to improve the mechanical and barrier properties of the nanocomposites. PLLA based nanocomposites with PMMA modified CNCs showed higher storage modulus

This experiment was conducted to find the absorbance of light by blood glucose samples taken from nondiabetics and diabetics taken before a meal and every thirty minutes for two hours after the meal. The hypothesis for this experiment is that diabetics have a greater absorbance than nondiabetics because diabetics cannot properly regulate their glucose levels. The samples were taken before a meal then taken every thirty minutes after the meal over the course of two hours. This samples were then put into a spectrophotometer to get the absorbance of each. These values were recorded and averaged with the absorbance values from other groups within the lab. The absorbance values show that the diabetic blood glucose samples have a

Title: Optical Absorbance and Quantitation of Light Absorbing Molecules Name: Kaylen Meeks Lab Partner: Quin Waterbury Date Experiment Performed: 1/16/2018 INTRODUCTION Stock solutions are stored in freezing temperatures for long term storage in many biochemistry labs. The freezing and thawing of these solutions will influence the concentration. To display this phenomenon, ampicillin that had been frozen was thawed. Samples were taken at various times and their absorbances were measured with a spectrometer.

When exposed to sunlight, the the top layer of plasmonic nanoparticle discs produces hot electrons. After this step is complete, it is vital that the hot electrons are alienated from the electron holes, in order to preserve their energy. The middle layer of aluminum plays its part, as it causes for the electron holes to gravitate toward it. The bottom layer of nickel oxide traps the hot electrons, while allowing for the electron holes to pass through. If the device is immersed in water, the molecules can then be broken down into simpler

The highly conjugated system of the cyanine dyes makes it a very good compound in the development of more efficient solar cells. In this experiment, the maximum wavelength was measured for nine dyes using a UV-Vis spectrum. The result that were obtained agreed with Kuhn’s model for the less polarizable end groups such as 3,3 '-diethyloxadicarbocyanine and 3,3 '-diethyloxatricarbocyanine. That suggested that these two compounds were not as easy to polarize compared to the rest of the dyes. The rest of the dyes required the use of the empirical parameter α to provide more reliable predictions of the wavelengths. This was due to the highly polarized ends of the dyes which needed the adjustment of the parameter to get more accurate results. The series with the higher polarizable end groups’ absorbed higher wavelength light than the less polarized groups. This supported the idea of the one-dimensional box. Also, higher wavelength was determined to be associated with longer conjugated carbon methine chains between the Nitrogen atoms. Kuhn’s free electron model was very reliable for this system.

A general increase in absorbance values is seen in all three curves. All curves plateau at various temperatures. The absorbance was taken at 260nm. Temperature values ranged from 70°C to 96°C.

As we are going up, it’s obvious that the bond strength is getting weaker because the atomic radius increases; the orbital overlap decreases (Long bonds are weaker than short bonds).

PPV, otherwise known as polyphenylene vinylene are electric conductors that processed into tiny films which emit a bright fluorescent yellow light which could potentially be a replacement for LEDS in electronics. PPV is prepared from p-xylene-bis and the addition of acetonitrile-tetrabutylammonium tetrafluoroborate and from there, the product is treated with heat to eliminate diethyl sulfide, HCL, and ethyl sulfide to form the final product, PPV. Similarly, another method, called direct chemical polymerization, formed PPV but it was only in the form of powder which could not be turned into tiny films for commercial use. In lab, we learned that PPV precursor can be synthesized in a one step reaction from p-xylene using NBs. In the reaction with

XRD analysis was performed using a PanAlytical X-ray diffractometer with a Cu anode, generating Kα radiation (=1.54046 Å) and operating at 40 kV and 30 mA. Raman spectra were recorded at room temperature with a Bruker Optik GmbH Raman microscope-spectrometer Senterra using a 100x MPLN Olympus objective. The wavelength of the excitation laser was 448 nm. Surface morphology was analyzed by SEM on a Raith PIONEER System and the particle size distribution histogram was determined using particle detection software (SPIP, Image Metrology). A Nanosurf easyScan 2 AFM (Nanosurf, Liestal, Switzerland) in contact mode was employed to obtain topographical images and the Gwyddion software [34] was used for image processing and root mean square roughness (Rrms) calculation. The electrical properties such as resistivity and carrier concentration were determined from Hall Effect measurements at room temperature using an Ecopia HMS-300 system based on the van-der-Pauw method. The optical transmittance spectra were recorded at room temperature by a Safas UVmc2 UV–Vis spectrophotometer and the optical bandgap energy data was then derived from the transmission spectra. The optical waveguiding characterizations were carried with a Metricon Model 2010/M Prism Coupler System equipped with a polarized He-Ne laser beam operating at a 632.8 nm wavelength. A Veeco Dektak 150 Surface Profiler was used for film thickness investigation. The thickness of the AZO films prepared at 6, 12, 18 and 24 coatings was measured to be 232, 425, 617 and 798 ± 1 nm,

The photoelectron combines with a silver ion to form a neutral metallic silver atom. (Earle

Gold(III) chloride solution and sodium citrate solution were freshly prepared with deionized water and filtered through a syringe filter (0.22 µm). Deionized water (45 mL) was added into three-neck flask incubated in the heating mantle with a stirring bar followed by the addition of HAuCl4 solution (5 mL, 10 mM). After the solution was boiling, the sodium citrate solution (5 mL, 38.8 mM) was added quickly. The color of the mixture gradually changed from black to wine red in the first two minutes, indicating the formation of gold nanoparticles. The AuNPs solution was kept boiling for another 10 minutes with a stirring speed of 700 rpm. After cooling down the solution to room temperature, the AuNP solution was filtered through a syringe filter (0.22µm). The concentration of AuNPs was determined by UV-Vis spectrometer (Cary100,