The Chemistry and History of Silly Putty

The Chemistry and History of Silly Putty Silly Putty is an amazing stretchy toy thats sold in a plastic egg. In the modern era, you can find many different types of Silly Putty, including types that change colors and glow in the dark. The original product was actually the result of an accident. Silly Putty History James Wright, an engineer at General Electrics New Haven laboratory, may have invented silly putty in 1943 when he accidentally dropped boric acid into silicone oil. Dr. Earl Warrick, of the Dow Corning Corporation, also developed a bouncing silicone putty in 1943. Both GE and Dow Corning were trying to make an inexpensive synthetic rubber to support the war effort. The material resulting from the mixture of boric acid and silicone stretched and bounced farther than rubber, even at extreme temperatures. As an added bonus, the putty copied newspaper or comic-book print. An unemployed copywriter named Peter Hodgson saw the putty at toy store, where it was being marketed for adults as a novelty item. Hodgson bought the production rights from GE and renamed the polymer Silly Putty. He packaged it in plastic eggs because Easter was on the way and introduced it at the International Toy Fair in New York in February of 1950. Silly Putty was a lot of fun to play with, but practical applications for the product werent found until after it became a popular toy. How Silly Putty Works Silly Putty is a viscoelastic liquid or non-Newtonian fluid. It acts primarily as a viscous liquid, though it can have properties of an elastic solid, too. Silly Putty is primarily polydimethylsiloxane (PDMS). There are covalent bonds within the polymer, but hydrogen bonds between the molecules. The hydrogen bonds can be readily broken. When small amounts of stress are slowly applied to the putty, only a few of the bonds are broken. Under these condition, the putty flows. When more stress is applied quickly, many bonds are broken, causing the putty to tear. Lets Make Silly Putty! Silly Putty is a patented invention, so specifics are a trade secret. One way to make the polymer is by reacting dimethyldichlorosilane in diethyl ether with water. The ether solution of the silicone oil is washed with an aqueous sodium bicarbonate solution. The ether is evaporated off. Powdered boric oxide is added to the oil and heated to make the putty. These are chemicals the average person doesnt want to mess with, plus the initial reaction can be violent. There are safe and easy alternatives, though, that you can make with common household ingredients: Silly Putty Recipe #1 This recipe forms a slime with a thicker consistency, similar to that of putty. Solution of 55% Elmers glue solution in waterSolution of 16% sodium borate (Borax) in waterFood coloring (optional)Ziploc bags Mix together 4 parts of the glue solution with one part of the borax solution. Add food coloring, if desired. Refrigerate the mixture in the sealed bag when not in use. Silly Putty Recipe #2 The glue and starch recipe may also be seen as a slime recipe by some people, but the materials behavior is much like that of putty. 2 Parts Elmers white glue1 Part liquid starch Gradually mix the starch into the glue. More starch may be added if the mixture seems too sticky. Food coloring may be added, if desired. Cover and refrigerate the putty when not in use. This putty can be pulled, twisted, or cut with scissors. If the putty is left to rest, it will pool out, like a thick liquid. Things to Do With Silly Putty Silly putty bounces like a rubber ball (except higher), will break from a sharp blow, can be stretched, and will melt into a puddle after a length of time. If you flatten it and press it over comic book or some newpaper print, it will copy the image. Bouncing Silly Putty If you shape Silly Putty into a ball and bounce it off a hard, smooth surface it will bounce higher than a rubber ball. Cooling the putty improves its bounce. Try putting the putty in the freezer for an hour. How does it compare with warm putty? Silly Putty can have a rebound of 80%, meaning it can bounce back to 80% of the height from which it was dropped. Floating Silly Putty The specific gravity of Silly Putty is 1.14. This means it is more dense than water and would be expected to sink. However, you can cause Silly Putty to float. Silly Putty in its plastic egg will float. Silly putty shaped like a boat will float on the surface of water. If you roll Silly Putty into tiny spheres, you can float them by dropping them into a glass of water into which you have added a little vinegar and baking soda. The reaction produces bubbles of carbon dioxide gas, which will stick to the spheres of putty and cause them to float. As the gas bubbles fall off, the putty will sink. The Solid Liquid You can mold Silly Putty into a solid form. If you chill the putty, it will hold its shape longer. However, Silly Putty isnt really a solid. Gravity will take its toll, so any masterpiece you sculpt with Silly Putty will slowly soften and run. Try sticking a glob of Silly Putty to the side of your refrigerator. It will stay as a glob, showing your fingerprints. Eventually it will start to ooze down the side of the refrigerator. There is a limit to this it wont run like a drop of water. However, Silly Putty flows.

Pressure Ulcers Research Paper Example | Topics and Well Written Essays - 1500 words

Pressure Ulcers - Research Paper Example One such strategy is use of assessment tools for evaluation. In this essay, the role of assessment tools in the prevention and management of pressure ulcers effectively will be discussed through review of appropriate research articles for evidence-based information. Pressure ulcers are a common source of distress in any health care setting. They contribute to morbidity and mortality and are a significant source of healthcare cost. It is often difficult to treat pressure ulcers because of lack of proper understanding of the complexities involved in the causes of breakdown of skin (Riordan and Voegeli, 2009). This research is intended to evaluate and ascertain the benefits of using assessment tools in the prevention and management of pressure ulcers and in total decrease the incidence and prevalence of pressure ulcers in any health care setting. The article begins with the prevalence of the pressure ulcers in Europe and the impact they have on the patient, community and society. This is followed by the definition of pressure ulcer. According to the authors, pressure ulcers are "areas of localized damage to the skin and underlying tissue caused by exposure to pressure, shear or friction, or a combination of these." While most of the pressure ulcers affect only the skin, severe forms of ulcers involve other structures like muscle, bone and tendons. Pressure ulcers develop because of sustained high pressure in an area of the body, mostly over the prominences of bones. Due to the raised pressure, the capillaries supplying blood supply to a particular region get compressed resulting in ischemia of the tissue. Other than ischemia, thrombosis of the venous system and occlusion of the lymphatic vessels of the area also are affected because of pressure. All these eventually lead to increased permeability of the capillaries, intersti tial edema and tissue death. The article provides an

Task 1 and Task 2one is essay and one is repport choose The - 1

Task 1 and Task 2one is and one is repport choose The Philippines currency - Essay Example This causes the domestic currency to appreciate. In addition, under this regime, an increase in international real interest rates increases domestic output, decreases exchange rates and domestic price level on condition that money demand is more elastic to changes in the real income than the real interest rates. An increase in domestic money supply causes a proportional increase in the price levels. In this model, the income of a consumer is assumed to be exogenous. The consumer is also assumed to be living in both the present and future periods. The consumer can also borrow and lend regardless of the prevailing world interests rates. The model also assumes that there is no investment made and the current and future government expenditure (G and G’ respectively) is exogenous. A Current Account Surplus implies that a particular country saves more than it invests. It is reflected by an excess of domestic savings over domestic investments and an increase in a country’s net foreign assets evidenced by positive sales abroad. The model suggests a positive relationship between the current account surplus and the current income. As the current income increases, the current account surplus also rises due to an increase in current consumption and government expenditure. The current account surplus experiences an inverse relationship with anticipated future income. As the fu ture income is expected to rise, the current account surplus is expected to reduce as a result of reduction in savings. When the current account surplus is zero, the country’s savings equals the investments. Capital controls refer to prohibitions enforced by the government or Central Bank of a country to restrict the flow of foreign capital in the domestic economy. Capital controls could be exchange controls, taxes, legislation, volume restrictions and reduction in foreign remittances which reduce foreign trade. Capital