Recent content by vinhphysics

I am doing research on synthesis of copper nano particles. I would like to have a cyclic voltammetry (CV) of this material but I don't know how to prepare sample. Please tell me the ways to carry out this measurement. Thank you so much!

Dear all, I am preparing nano Cu particle by reaction of CuCl2 with NaBH4 in PVP solution. CuCl2 and PVP were mixed ultrasonically in pure water. Before dropping NaBH4 solution, the water was bubbled by N2 to remove O2. After dropping NaBH4, the solution turns into gold color. This means that...

I read some books which mention about covalent and partially covalent chemical bonds. However, I cannot distinguish between them. Who can help me? Thank you very much!

Thank you Darwin123 for your discussions. May be I had a mistake in using the scientific terms. What I want to say is some materials absorb all photons which their energy are higher than the band gap of material while some materials absorb strongly the photons which have certain energy. This...

The peaks means we can find some maximum points on the spectrum (See absorption spectrum in link: http://www.viewsfromscience.com/documents/webpages/nanocrystals.html ). The Band means no maximum points can be found on the spectrum (See absorption spectrum in link...

The absorption spectra of some materials appear as the absorption bands (for example: TiO2 powder) while the other appear as the absorption peaks (for example: Quantum dots). Please explain why they are different?

Hello all, We would like to build a system in order to evaluate the performance of air-conditioning. Who can help us to disign this system or introduce the company where we can consult? thank you! Pham Vinh

Hello all, I would like to know what chemical composition of laser ink is and how to make it? Thank you!

Hello all, Who can tell me the ralationship between crystal and hardness of the coatings. I do XRD and measure hardness but the some coatings with high intensity of XRD peak show the low hardness. The questions are: what direction of planes is useful for hadrness? what elements affect on...

Thanks you! I think TEM cross section can be used to estimate the thickness of layer. I will try to do it in near future. Thanks you for your interest.

Hi! I am doing research on TiAlSiN coatings. The coatings are multilayers of crystalline TiN and amorphous (Al,Si)N. The thickness of each layer is estimated about some nano-meters. The question is How can I measure the thickness of each layer? and What measurement of method is the best...