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Questions related from Gyorgy Banhegyi
I have recently heard about the complete phaseout of ALL perfluorinated compounds, not only surfactants but also all polymers, including copolymers containing minority comonomers with a single...
15 June 2023 4,959 8 View
I wonder whether there is any simple model to predict the moduli of miscible, or at least technically compatible polymer blends or copolymers vs. composition, where a single Tg is observed? The...
22 August 2022 4,268 2 View
I am aware of the fact that the Havriliak-Negami shape factors are purely empirical parameters that can be used to describe the deviation from the ideal Debye response and as such, they have no...
22 August 2022 2,000 0 View
The use of horizontal shift factors fo determining the activation energy of a relaxation process (e.g. creep or stress relaxation) is well known from the literature. Usually, if possible, only...
14 December 2021 3,046 4 View
Dear Colleagues, it is well known that contact angle hysteresis (the difference between the advancing and receding contact angles) is influenced both by surface roughness and by the...
24 August 2021 8,767 5 View
Dear Colleagues, I am familiar with contact angle measurments with "normal" low viscosity liquids (including time dendent phenomena) as decades ago I dealt with the surface recovery process in...
28 July 2020 4,726 3 View
Dear Colleagues, Most articles recommend using E' or G' for estimating the crosslink density in rubbers. In an actual set of measurements I tried to compare 10% secant moduli with E' values above...
18 June 2020 8,036 7 View
It is a sad experience I gathered on RG the more often than not research supervisors at universities and at other academic institutions do not give the necessary support to their BSc, MSc or PhD...
06 March 2020 7,608 5 View
Dear Colleagues, if powders with different diameters and chemical natrue are mixed/milled in either dry or wet states the smaller powders may agglomerate on the surface of the larger particles...
17 January 2020 7,983 2 View
Dear Colleagues, when measuring size distribution of solid dispersions by light scattering, it is a usual practice to approximate the equilibrium size distribution by applying ultrasound...
17 January 2020 9,888 3 View
Dear Colleagues, According to my understanding, in addition to SIMS and MALDI/TOF ambient (?) pressure plasma ionization is used for the characterization of polymers and their surfaces. If some...
10 April 2018 8,897 5 View
I have been long interested in the measurement and theoretical/empirical description of the dielectric properties of heterogeneous mixtures. In the case of non-conducting or semiconducting fillers...
25 March 2018 1,729 1 View
Dear Colleagues, I am aware of the fact that approximate spherulite size can be determined from POM (polarization optical micrographs), especially if the nucleation is not very dense and the outer...
20 March 2018 1,301 0 View
First of all, I am chemist, not an AI specialist, therefore my question may be naive. One can read a lot about the rapid development of AI-s not only in sci-fi novels. I wonder whether artificial...
14 November 2017 4,997 6 View
One can frequently hear from devout Christians (and probably from devout Muslims etc.) that the main problem of the modern age is relativism in general and specifically ethical and religious...
04 August 2017 3,853 9 View
Dear Colleagues, this is actually not an question but a simple aid, as many asked for help in HN fitting. The attached file helps to make the first, approximative steps in fitting Havriliak Negami...
21 July 2017 6,424 12 View
Dear Colleagues, In automatized quantum chemical calculations (such as Chem Bio 3D Ultra) sometimes the IR/Raman spectra are not generated due to the fact that out of the first 6 frequencies...
21 April 2017 9,312 7 View
I have tried to find tabular data on the solubilities of various kinds of metal-organic compounds (mainly alkoxane derivatives of transition metals) in organic solvents and I have found mostly...
18 December 2016 1,272 11 View
I have collected several papers and PhD theses on the quantum chemical estimation of polymerization kinetic constants. Out of curiosity I also tried to make calculations on acrylic/methacrylic...
20 July 2016 7,252 5 View
I have collected a sizeable amount of papers on radical polymerization kinetics. i also know that there exist excellent commercial programs such as e.g. Predici, but they are very expensive....
17 May 2016 870 3 View
Bulk polymerization process can be monitored by various techniques, such as FTIR, NIR, dielectric analysis, chromatography, viscometry, ultrasound etc.In the case of copolymerization the...
11 April 2016 5,917 18 View
I know the general background of using light scattering for determining e.g. molecular weights. I would appreciate, however, comments on the uses of light scattering on the characterization of...
19 April 2015 3,438 8 View
Ahesion is more or less straightforward if we want to glue together tow metarials. Peeling test works if one of the substrates is flexible. The physical picture is more or less clear. But how can...
25 March 2015 7,766 5 View
When interpreting SIMS (secondary ion mass spectrometry) data obtained on organic (polymeric) surfaces how much can one rely on MS databases which usually contain electron ionization MS data? How...
06 February 2015 1,480 4 View
Could you suggest sources available on the Internet on (estimated) demographic data in various regions of ancient Asia (India, China, Central Asia, Near East) etc?
19 January 2015 7,746 3 View
Dear Colleagues Does anyone have experiece with commercially available sofware developed for simulating muli-component copolymerization kinetics, composition, viscosity, conversion etc....
27 December 2014 8,753 11 View
I am puzzled by a strange frequency dependence of the AC conductivity published for some carbon-filled (e.g. graphite, carbon black or combined carbon fillers) polymer composites above the...
17 June 2014 8,683 2 View
Is it possible to make the production of SiC ceramics cheaper by using cheaper raw materials (as e.g. carbon black from recycled tires and Si powder from semiconductor industry or other...
11 December 2013 3,358 3 View
Does anybody have experience with using prepreg tapes for fixing joints (in engineering structures)? If yes, is it necessary to use robots for applying such tapes, or manual application of the...
01 April 2013 3,272 1 View
We plan to start powder injection molding experiment in our lab - mostly with ceramics, but also with metal powders. So far we were successful in preparing polymer based feedstock with high...
03 November 2012 6,857 15 View
