Ma. Flynne Dagalea

University of the Philippines | UPD · Department of Science

My goal is to counter-check my SEM photo against my XRD data, which the latter (XRD) confirms that I had an almost spherical particle in nanosize scale.

I think my sample is still aggregated in my SEM, could help describe it?

Thank you

Can you give the exact chemical equation for synthesizing hydroxyapatite from: calcium acetate and ammonium phosphate?

Literature about Hap synthesis from calcium acetate and ammonium phosphate would also be appreciated.

Thank you

Best

Flynne

The data below were generated from XRD hydroxyapatite, but I'm confused about what should I use to first graph my diffractogram and most importantly the crystallinity of my sample.

Could tell me what data (for example 2 theta and Intensity ) should I use in Origin?

Best Regards,

MF

Decomposition temperature of benzyl alcohol?

Decomposition temperature of organic dye?

I'm at the end of my preliminary experiment for the synthesis of Hap, but I noticed traces of black ink in my dried hydroxyapatite, I tried to search at which temperature the component in black ink decomposes, but I'm still quite unsure.

Best Regards

-Flynne

Good eve.

I am afraid of overshooting the pH of hydroxyapatite solution by combining, Ca(OH)2 suspension and phosphoric acid. Can you suggest an acid solution to adjust the pH=10?

Recently I learned that I could use 28%-30% ammonia solution in increasing the pH=10, what if I accidentally surpassed, what acid solution and concentration should I add?

Hi I am looking for a simple standardization procedure in standardizing 0.25M Phosphoric acid, perhaps with NaOH, please if you know a procedure. do tell.

Thank you!

Which has the capability to determine the molar ratio of Ca/P of hydroxyapatite ; XRD or SEM-EDS?

How is hydroxyapatite formed from calcium acetate and phosphoric acid by chemical precipitation method? Could you explain how can I derive the intermediate calcium hydroxide from it?

Good day!

I plan to do away from calcination in preparing nano hydroxyapatite;

Could you recommend readings or protocols on nHAp synthesis using the dissolution of calcium carbonate in acetic acid?

Thank you

Regards,

-BS Chemistry undergraduate

Greetings,

Calcium nitrate tetrahydrate and di ammonium hydrogen phosphate were used as precursors for Calcium and Phosphate elements respectively. Corresponding molar solution of calcium nitrate tetrahydrate and diammonium hydrogen phosphate were prepared in 100 ml DDW. Solution of di ammonium hydrogen phosphate was added dropwise in calcium nitrate tetrahydrate solution with continuous stirring. The reaction mixture was then transferred to the 800 W household microwave (SHARP, model R-218LS) to reflux for 30 min [5]. Resulting precipitates were filtered, washed with distilled water, dried in the oven at 80 ºC for 17 h and calcined in muffle furnace at 1000 ºC for 2 h.

Five samples (A, B, C, D & E) of HA were prepared with Ca/P ratio 1.5, 1.6, 1.67, 1.7 and 1.8 respectively.

Q: How do I create a molar solution of calcium nitrate tetrahydrate and diammonium hydrogen phosphate for an HA with a Ca/P of 1.67?

Please help me understand by showing calculations.

Thank you

Sincerely

BS Chemistry undergrad.

Greetings,

I am confused as to how can I create hydroxyapatite nanoparticles within the recommended Ca:P ratio? Please give me examples using Ca(OH) and Diammonium Hydrogen Phosphate/Orthophosphoric acid.

Regards:

BS Chemistry undergraduate.