Soumia Cheddah

7 Questions 16 Answers 0 Followers

Questions related from Soumia Cheddah

Why the density of silanol groups calculated from TGA is higher than the Zhuravlev constant (8 micromol/m2)?

I have nonporous silica particles with a size of 400 nm and a BET surface area of 10.4 m2/g (mode of pore size 1.87 nm). I measured the weight loss during TG analysis and it was 0.93% (second step...

15 March 2023 1,593 0 View

Does capillary attractive force between particles in an evaporating dispersion depend on the evaporation rate of the solvent?

In a dispersion of colloidal particles under evaporation, there is generation of a capillary force which bring the particles closer, if the evaporation rate is higher, the capillary flow will...

02 November 2022 9,869 2 View

How to accurately calculate the filling factor of a photonic colloidal crystal from its reflection wavelength?

The crystal structure is FCC (for a perfect crystal the theoretical filling factor or volume fraction of particles should be 0.74), particles are silica with a refractive index of 1.42 and a...

29 March 2022 6,249 11 View

Dynamic light scattering for characterization of micelles, I am always detecting a big particle more than 100 nm, why is that?

I am trying to determine the size of micelles of a surfactant in toluene and THF, but each time the size determined from intensity is showing two peaks, one is below 10 nm (I assume that is my...

13 July 2020 2,588 18 View

How to calulate surface coverage of alkyltrichlorosilane grafted on silica particles from 29Si solide state NMR?

During the reaction of trifunctional alkylsilane, one or two linkagea are formed per silane molecule leading to a stoichiometric factor. How we can estimate this factor from 29Si solid state NMR?...

30 August 2019 856 6 View

Is it possible to measure zeta potential in an organic solvent?

My silica particles bear hydrophobic moieties and residual silanol groups, they can only be suspended in an organic solvent but I believe they still have a certain electrostatic interaction due to...

24 July 2019 6,844 15 View

How to cut a sample for SEM analysis (cross-section of a capillary packed column)?

We are preparing new packed capillary columns (packed with silica particles) for capillary electrochromatography. One of the techniques we use for the characterization is SEM of the cross section,...

10 December 2018 959 4 View