Richa Ghosh

13 Questions 20 Answers 0 Followers

Questions related from Richa Ghosh

Z-average size from Dynamic Light scattering can it be lower than the original probe size?

Hi everyone, Recently I have been conducting Dynamic Light scattering experiments in a micellar solution at 5 and gel at 37 degrees of Celsius with latex particles of diameter 190-500 nm. While...

02 August 2024 1,912 4 View

Viscosity or Complex viscosity should be used in the SOP for Malvern Zetasizer or carrying out DLS experiments for polymer samples?

Hi all, I am trying to conduct Dynamic Light scattering experiments on polymer sample using Malvern Zetasizer ZS. One question I have is to whether it is okay to use complex viscosity instead of...

12 May 2024 4,690 7 View

Any threshold of fluctuation of scattering intensity vs measurement position when it comes to determining ergodicity or non-ergodicity medium?

I have come across several articles where they talk about the scattering intensity varies considerably with measurement position for non-ergodic medium as compared to ergodic medium. Is that is...

20 January 2024 6,665 0 View

How to determine the range of measurement positions one need to set for studying the light scattering intensity in an non-ergodic medium?

Hi, so I have been reading a bunch of research papers on how to do dynamic light scattering experiments in an non-ergodic medium. 1. Couple of them suggest to take the reading from a single...

08 December 2023 3,791 9 View

After preparing a stock solution lets say of PVA, how do you decide on the filter size before doing DLS experiment??

Before doing DLS experiment, it is recommended that one should filter their solution to get rid of dusts, or make the stock solutions clean optically by usage of filter. But when it comes to doing...

25 September 2023 3,684 3 View

DLS zetasizer: countrate report necessary?

Hi, I am dealing with polydisperse medium by using Malvern Zetasizer ZS. Is getting the count rate graph necessary for CONTIN analysis? I have come across several python codes in GITHUB where...

18 September 2023 3,263 3 View

Why is the temperature for a composition of Poly-vinyl alcohol (PVA) and phytagel heated to 90 Celsius and then mixed on 1:1 ratio at 70 Celsius?

I am following several papers where they have formed hydrogel phantoms which represents artificial lung/brain etc. In almost all the papers, they have performed the same material preparation that...

30 August 2023 3,568 0 View

Can I use a rheometer to measure very less viscosity like water or something close to it?

Hi, I am looking to conduct rheometric experiments on water or hydrogels whose viscosity is very less. Should I use Dynamic light scattering or a rheometer?

27 June 2023 8,729 14 View

Can I use water instead of Phytagel for performing Dynamic Light scattering using silica beads entrapped in the hydrogel?

Hi, I am using Malvern's Zetasizer to get the rheological properties of the hydrogel formed with Phytagel containing silica beads entrapped in the said hydrogel. When I am taking the readings...

13 June 2023 2,225 7 View

Does working with Quadrant Photo diode QPD requires HPC or any fast computer processing?

Hi, I am working with QPD for particle tracking. I have been using video tracking which involves particle tracking frame by frame. So far I have been using high performance computer (hpc) for...

18 April 2023 694 0 View

How to decide which parameters I need to change for optical trapping of silica beads in water?

Hi, I am working on optical trapping of silica particles of size 1-3 um dia. My calibration curve shows that the spring constant increases with power within this diameter range. The wavelength of...

15 April 2023 9,867 0 View

Can the viscosity of water in Optical trapping come out double that of bulk viscosiy?

I am trapping a 1-3 um sized silica particle in water. The viscosity obtained from auto correlation function is coming out double that of viscosity of water at 20 degree Celsius. Can that happen...

06 April 2023 1,904 2 View

How to focus the particle of micron size for optical trapping by laser?

I am doing optical trapping of a particle of micron size by laser (800 nm). I have noticed that for the same power, with a slight change in focusing the stiffness constant varies a lot. How do you...

05 April 2023 5,273 1 View