23 Questions 13 Answers 0 Followers
Questions related from Dmitry Bagrov
Hello! When we purchase a biodegradable polyester (PLA, PCL, PHB and others), the manufacturer usually reports the viscosity of a chloroform solution of this polymer. For example, "viscosity ~1.5...
06 April 2025 9,092 4 View
Hello! I work with carbon quantum dots (carbon nanoparticles with intense fluorescence) and I want to image them using a TEM. I have seen dozens of TEM images showing carbon quantum dots as dark...
11 February 2025 3,372 3 View
Hello! I am preparing liposomes using a membrane extruder. The procedure is well-known and descibed extensively in the literature: 1. I start with a solution of the lipid in chloroform, then...
20 August 2024 3,855 3 View
Hello everyone! Glow discharge treatment of TEM carbon-coated grids is a commonly used routine. Usually the grids are placed onto the cathode, and they are separated from the cathode by a glass...
09 April 2024 5,201 3 View
Hello! I treat a polymer surface with plasma and I expect that some free radicals form on it, because it demonstrates high adsorption. How could I quantify the presence of free radicals on a...
02 November 2023 774 2 View
Hello! I need a solid (non-porous) nitrocellulose film, and I am trying to prepare it by solution-casting. I dissolve nitrocellulose in acetone, dimethylformamide or their mixture, pour the...
11 September 2023 491 2 View
Hello! I have a question about the pores in membranes. Membranes made of nitrocellulose, PVDF, nylon and other polymers are widely used in laboratories for blotting, filtering, etc. Almost any...
28 March 2023 9,857 3 View
Hello everyone! I have a pair of images (A and B) of the same object, and these images were taken at different time moments. Some parts of the object shifted, deformed or even disappeared;...
26 October 2022 4,340 4 View
I want to measure the protein concentration C, and I know that my protein of interest is the only protein that I have in solution. Why don't people use intrinsic Phe, Tyr, Trp fluorescence for...
12 November 2021 9,103 5 View
Hello! I am looking for examples of industrial processes which are catalyzed by enzymes (either natural or recombinant). Particularly, I am interested in processes that end up with enzyme removal...
09 October 2021 1,683 6 View
Hello! Small liposomes (100-200 nm) can hardly be pelleted using a centrifuge. I want to prepare saccharide-loaded liposomes, which could be pelleted relatively easily (I plan to make a...
11 March 2021 5,379 1 View
I want to prepare liposomes made of azolectin (sometimes spelled as asolectin). I start with the azolectin powder, and many protocols say that I should wash it with acetone (dissolve, centrifuge,...
05 February 2021 3,103 3 View
I want to use fluorescence microscopy to study fibroblasts grown on electrospun mats. Although such experiments are widely described in the literature, I faced a problem. We usually immerse the...
08 July 2020 9,494 4 View
Hello! I have a basic question about polymer chemistry. I work with solutions of polyesters and other polymers in organic solvents. Sometimes I add the solvent to the polymer granules and get a...
25 April 2020 6,692 0 View
Hello! I am trying to make soft litography (microcontact printing) using a stamp made of a photocurable elastomer. I did several sucsessful experiments transerring biopolymers from the elastomer...
07 December 2018 1,796 1 View
I want to measure the molecular weight distribution of a linear polyester (polylactide, poly(e-caprolactone) or a similar polymer) using GPC. As far as I know, it is usually done with a refractive...
09 March 2018 2,027 4 View
Silk fibroin is a well-known biodegradable material, and there are hundreds of publications about the usage of silk fibroin in tissue engineering, wound healing, drug delivery etc. However, silk...
21 June 2017 2,449 5 View
Hello everyone! Could you please help me with interpretation of a compression test experiment? I carry out compression test on a hydrogel sample. The sample is a wet cylinder compressed between...
08 May 2016 2,692 10 View
Thermal denaturation of proteins can be studied by differential scanning calorimetry (DSC). It works mostly with protein solutions, and I can't find any information about the DSC experiments on...
04 March 2016 1,192 2 View
On one hand, most foreign proteins are immunogenic. On the other hand, serum albumin is highly conservative and it has similar structure in different species. So if we inject a mouse with HSA or...
01 January 1970 8,948 1 View
Is there a fundamental theory of polymer fibers and nanofibers? I work with polymer fibers and I am interested in whether there is a fundamental theory to describe them. Suppose fibers are...
01 January 1970 492 4 View
Hello! I have a question about the charge of the jet in electrospinning. Let's regard electrospinning of a polymer-solvent system. The solution is ionized at the needle and moves towards the...
01 January 1970 8,978 1 View
Hello! I am looking for some hints on how to estimate the kinetics of phase separation in a mixture. I regard a ternary immiscible blend of two polymers A and B in a common solvent C. The phase...
01 January 1970 6,544 2 View
