Here are two easy projects using 3 mm ultraviolet LED's and a solar cell with a boost circuit. Based on a Joule Thief, and here the joule refers to the unit of energy not anything stolen. The concept of edge lighting acrylic or plexiglass, persplex, if you are in Great Britain, has been around for a long time. But, there always seems like there is more to do with the idea, and so I offer these simple ideas. The solar rock lights shown in the photo and in the video were purchased at a Dollar Tree store for a dollar of course. But, they are available online in single or case quantities if you decide to make and sell these little note boards in a frame. After the video there are inset closeup photos and links to follow. These "electronic noteboards" are available already assembled for $7.95 at American Science and surplus. I have not seen them for real so I am not sure how they really look. And for other "neon effects" see my page on Odd n' Ends, under neon. Enjoy!
Video Below: Here are two easy projects using 3 mm ultraviolet LED's and a solar cell with a boost circuit. Based on a Joule Thief, and here the joule refers to the unit of energy not anything stolen. The concept of edge lighting acrylic or plexiglass, persplex, if you are in Great Britain, has been around for a long time. But, there always seems like there is more to do with the idea, and so I offer these simple ideas. The solar rock lights shown in the photo and in the video were purchased at a Dollar Tree store for a dollar of course. But, they are available online in single or case quantities if you decide to make and sell these little note boards in a frame. After the video there are inset closeup photos and links to follow. These "electronic noteboards" are available already assembled for $7.95 at American Science and surplus. I have not seen them for real so I am not sure how they really look. And for other "neon effects" see my page on Odd n' Ends, under neon. Enjoy!
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Video below: This is the third and final post on acids and bases, and natural pH indicators. I hope that it has been helpful and informative and leads to interest in the area of natural pH indicators. This entry is on Turmeric, an Indian spice that has been used as a dye for over 2000 years. Sometimes spelled tumeric, it contains curcumin, a polyphenol, that reacts with boron under specific conditions, to form a dye called rosocyanine. This test has been in use for about 100 years and the complex formed between the yellow curcumin and the element boron forms the rosocyanine which is a green crystal. The test as performed now is done spectrophometrically at 540 nm. So, the demonstration used as a visual determination is qualitative and not quantitative. Following the video will be a writeup and an explanation of what I have discovered as a result of my investigation that is somewhat different than material presented elsewhere. So, let's get to the video and the art deco chicken! The procedure for making the boron test paper is fairly easy but it does take two steps to prepare. I am not certain yet how long the test strips will be useful but my best guess is that if they are kept dry and protected from light that they will last for a long time.
CAUTION- The yellow color strength of the turmeric in alcohol is very strong and will stain any porous surface. I am still trying to clean up some of the mess! Materials needed: Turmeric- Available as a spice in most supermarkets. The tincture is made by adding 1 gram to 100 ml of 70% ethyl rubbing alcohol. (Drug store). Filter paper- But coffee filter paper will work as well. Sodium Hydroxide- Sold as lye at hardware stores. Make a 0.1 N solution with 4 grams made up to 1 liter of distilled water. Hydrochloric acid- Sold as muriatic acid 28% HCl (Hardware store). Make a 0.1 N solution with 17 ml made up to 1 liter. Boric acid- Sold as ant and roach powder at garden centers and hardware stores. Make a 2% solution with distilled water. Procedure: Dip the filter paper into the tincture of turmeric and let dry. Then, dip that paper into the 0.1 N HCl and let that dry. Now, dip that paper into the boric acid let that dry. The test paper is then dipped into the 0.1 N NaOH solution. A black to green-black color indicates the presence of elemental boron. You can test for boron in soil by taking 100 grams of soil and adding 100 ml of distilled water. Shake well and let sit overnight. Decant off the water and test. But remember that this test is strictly for the presence of boron, not the amount. For the art deco chicken, I coated the tincture onto some inkjet photo paper with a foam brush and let dry. Exposed through the positive image for 24 hours. Then, dipped in the HCl, dried, dipped in the boric acid, dried, and then in the 0.1 N NaOH as in the video. There is still some work to do on the imaging potential. For example, a base coat to keep the yellow on the surface and finding an additive that will make the curcumin even more sensitive to light. So much to do and so little time! Some closing thoughts... I have posted this entry in good faith and my investigation suggests that there is some incorrect information regarding the dye formed on several sites. In no way do I believe that any information that I have found on the web is intentionally misleading, but rather, that the chemistry is fairly complex. Although I have a background in chemistry, my lab is in my kitchen. Like many others, I don't have sophisticated equipment, and I buy my chemicals at garden centers, hardware stores, and other local places. And as others do, I make mistakes! If you can add to the discussion and shed more light on the subject, please comment. Hey, we are all in this together...Ken. |
AuthorThe author has an eclectic background in chemistry, electronics, writing, mental health, and community action...Ken Archives
June 2021
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