My polymer is glassy solid yet stuck to whatmann fiter paper. how can I obtain my polymer?

I precipitated the polymer in methanol and then tried to filter the polymer. However, my polymer stuck to whatman filter paper. how can I obtain the polymer now?

08 September 2018 373 2 View

I was not able to isolate the product from the DMSO . Please help me how to do it?

I want to synthesize the exo norbornene alcohol as was described in the reference.Macromolecules 2005, 38, 9455-9465. the problem is that I was not able to remove the DMSO solvent. Please help me...

06 July 2018 3,925 3 View

Can I dry macromonomers with Norbornene end cap at 120 degrees centigrade for 4 hours?

I synthesized polymers of PEO with different molecular weights with Norbornene end cap. I want to dry the sample in order to perform for the Ring Opening Metathesis Polymerization. Can I dry my...

05 June 2018 2,273 4 View

Is silica gel soluble/partially soluble in acetone?

we need to purify the pyrrolidone derivatives. When we checked the TLC, the compound Has Rf of 0.6 in acetone. But other solvents showed no movement of the spot from the base line. However, when I...

05 June 2018 2,345 3 View

Can we really trust the procedures published in the scientific journals?

I found that many procedures reported in the journals are not reproducable even when same conditions are maintained? why is it so?

10 November 2017 1,852 2 View

How to prepare 1, 1-Dipheynylmethyl Potassium ?

I want to prepare DPMK initiator for my polymerizations. Please give me a pdf file of the journal necessary.

08 September 2017 384 4 View

Is the refractive index of both monomer and polymer same?

07 August 2017 4,315 4 View

How to remove moisture from the polyethers?

I synthesized polyethylene glycol. I need to remove moisture from the polymer. T tried freeze drying but it didn't work please suggest me some other method which removes moisture. Thanking You in...

07 August 2017 2,411 9 View

Please let me know about the good practical books for learning glass blowing techniques.?

glass blowing for Schlenk techniques

03 April 2016 943 2 View

What is the weight of the polymer 'polyisoprene' with a molecular weight of 10000?

please help me in calculating the weight of the polyisoprene whose molecular weight is 10000.

02 March 2016 974 0 View

Can polymer concentrations be calculated based on the number average molecular weight?

Hello, I spin-cast two different polymers onto wafers and measure their height as a function of initial concentration. For polymer A, I have the weight-average molecular weight (Mw) as well as...

28 February 2021 7,882 2 View

How to resolve Gaussian error termination " Error termination via Lnk1e in F:\G16W\l103.exe" for TS(QST3)?

When I run the job for TS(QST3) in gaseous phase, it was completed without any error. But when I add water in CPCM model it terminated with an error: Inconsistency: ModMin= 2 Eigenvalue=...

21 February 2021 3,198 2 View

Using the Pfaffl method: Is it possible that the ratio of the calibrator does not equal 1?

Hi all, I have a question regarding calculations using the Pfaffl method. I have 3 groups per experiment: 1 control group (calibrator) and 2 treatment groups with 6 to 7 biological repeats per...

19 February 2021 8,351 2 View

How to calculate radial distribution function (RDF) of a complex from Ab initio MD simulation trajectory?

Hi all, Is there any software or webserver to read the molecular dynamics (MD) simulation trajectory which obtained from Ab initio MD simulation to calculate the atom-atom radial distribution...

25 January 2021 9,474 3 View

Solving diffusion- reversible chemical reaction equation: How to solve both terms numerically?

I am using finite difference method to discretize the parabolic equation (explicit method), but confused about the chemical reaction term. Solving the generic equation for i specie involves a...

24 January 2021 1,149 18 View

Doubt in DFT geometry preparation?

Hi all, I am trying to perform some ab inito DFT calculations using cp2k code. I have a unit cell of 120 atoms and would like to know how to refine or reduce the number of atoms in the unit cell...

20 January 2021 6,024 3 View

Why it is required to optimize a unit cell generated from cif lattice parameters and atomic coordinates during ab initio solid state calculations?

A cif file represents a unit cell with minimum energy. My question is, in the start of any ab initio calculation for unit cell generated from the cif file, why we are advised to optimize cell...

19 January 2021 9,883 3 View

Is it possible to calculate entalphy of LiBr/H2O or another solution if we know correlation of specific heat without using any software?

Is it possible to calculate entalphy of LiBr/H2O or another solution if we know correlation of specific heat without using any software?

17 January 2021 5,522 3 View

What is the best way to calculate electrical conductivity of semiconductors and the same system with a layer of oxide using Quantum Espresso?

I have tried BoltzTrap, and EPW but I'm not sure whether Boltzmann Transport Equation is a right approach for a complex system (semi cond. + an Oxide layer or even the semiconductor itself). Also...

11 January 2021 4,597 4 View

How to calculate IR and RAMAN spectra form Born charge ?

I am using crystal 17 for my solid state ab initio calculations. For some reason the program is not able to produce the Raman spectra but have generated born charges. Is there any way to produce...

11 January 2021 2,317 2 View