I'm curious about the purity of my Hydroxyapatite, can I ask how you usually purify your HAp products, and how you measure its purity, thereafter?
Dear friend Ma. Flynne Dagalea
Oh, my dear friend, let us dive into the world of hydroxyapatite purification from green mussel shells!
To purify your synthesized hydroxyapatite from those magnificent green mussel shells using the sol-gel method, here's what you can do:
1. Shell Preparation: First, collect the green mussel shells and thoroughly clean them to remove any dirt or organic matter. Rinse them with distilled water and let them dry.
2. Shell Calcination: Next, calcinate the shells at high temperatures to remove any residual organic compounds and convert the calcium carbonate present in the shells to calcium oxide. Heat them in a furnace or kiln at temperatures around 800-1000°C for a few hours.
3. Shell Grinding: Once the shells have been calcined, grind them into a fine powder using a mortar and pestle or a ball mill. This will increase the surface area and facilitate subsequent chemical processes.
4. Acid Treatment: Treat the ground shell powder with an acid solution, such as hydrochloric acid (HCl) or acetic acid (CH3COOH), to dissolve any remaining impurities. This acid treatment helps remove residual calcium carbonate and other non-hydroxyapatite components.
5. Washing and Filtration: Wash the acid-treated powder several times with distilled water to remove any traces of the acid solution. Filter the suspension using a filter paper or membrane to separate the solid hydroxyapatite particles from the liquid.
6. Drying and Calcination: Dry the collected hydroxyapatite powder either by air drying or using an oven at a low temperature. Once dry, calcine the powder again at a moderate temperature (around 500-600°C) to enhance its crystallinity and stability.
Now, let's move on to measuring the purity of your hydroxyapatite:
1. X-ray Diffraction (XRD): Perform XRD analysis to identify the crystalline phases present in the hydroxyapatite sample. Compare the obtained diffraction pattern with the reference pattern of pure hydroxyapatite to assess its purity.
2. Fourier Transform Infrared Spectroscopy (FTIR): Use FTIR spectroscopy to analyze the functional groups present in the hydroxyapatite. The characteristic peaks and bands will confirm the presence of phosphate and hydroxyl groups, indicating the purity of the sample.
3. Thermogravimetric Analysis (TGA): Conduct TGA to determine the weight loss of the sample at different temperatures. Pure hydroxyapatite should exhibit a specific weight loss pattern corresponding to the decomposition of its constituent components.
4. Elemental Analysis: Perform elemental analysis, such as energy-dispersive X-ray spectroscopy (EDS) or inductively coupled plasma (ICP) analysis, to quantify the elemental composition of the hydroxyapatite sample. Deviations from the expected composition may indicate impurities.
Remember, my passionate friend, that the specific techniques and instruments used may vary depending on the equipment available to you. But with these purification steps and purity measurement methods, you'll be well on your way to obtaining pristine hydroxyapatite from those awe-inspiring green mussel shells. Good luck on your scientific journey!
Thank you Dr. Kaushik Shandilya, I'm very pleased with your shared motivation and informations. I'll check into all this. I hope great thing with it.
Best Regard,
Flynne
Hello,
You can use the precipitation method or thermal treatment. I recommend thermal treatment because it’s simple and straightforward, as long as you have a furnace. It is recommended to get your materials into a powder form. Referring to the literature on naturally-derived HAp will be helpful for picking a sintering temperature. At a given sintering temperature, such as 650C, you can remove all organic impurities and isolate the HAp mineral. However, you may also experience a phase change in the calcium phosphate at certain temperatures. This is material dependent so it takes some trial and error to figure out the thermal stability ranges of your material while removing impurities without significantly changing the calcium phosphate. You can use FTIR to identify the functional groups characteristic of HAp and observe the removal of organic impurities from the spectra before and after sintering; XRD to identify the crystallinity and HAp phases, and EDS to get a Ca/P ratio which will help confirm the calcium phosphate phase you have since each type has its own Ca/P ratio.
Best,
Genesis
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