scholarly journals Mobility of bound water in PNIPAM microgels

2021 ◽  
Author(s):  
Tetyana Kyrey ◽  
Judith Witte ◽  
Jana Lutzki ◽  
Michaela Zamponi ◽  
Stefan Wellert ◽  
...  
Keyword(s):  
Crucial Role ◽  
Polymer Networks ◽  
Bound Water ◽  
Polymer Chains ◽  
Stimuli Responsive ◽  
Solvent Interactions ◽  
Polymer Solvent

Polymer-solvent interactions play a crucial role in the stimuli-responsive behaviour of polymer networks. They infuence the swelling/deswelling behaviour as well as the dynamics of the polymer chains. Scattering experiments provide...

scholarly journals Substrate-independent three-dimensional polymer nanosheets induced by solution casting

2021 ◽  
Author(s):  
Cheol Hun Park ◽  
Eun Min Go ◽  
Kyung Min Lee ◽  
Chang Soo Lee ◽  
Sang Kyu Kwak ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Simple Solution ◽  
Solution Casting ◽  
Solvent Interactions ◽  
Comb Copolymer ◽  
Substrate Independent ◽  
Polymer Solvent

Unprecedented substrate-independent polymeric 3D nanosheets were induced via simple solution casting using PEGBEM–POEM comb copolymer. A possible mechanism is the change in the polymer–solvent interactions on the surface.

scholarly journals Effect of Structure of Polymers Grafted from Graphene Oxide on the Compatibility of Particles with a Silicone-Based Environment and the Stimuli-Responsive Capabilities of Their Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 591 ◽  
Author(s):  
Monika Zygo ◽  
Miroslav Mrlik ◽  
Marketa Ilcikova ◽  
Martina Hrabalikova ◽  
Josef Osicka ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Graphene Oxide ◽  
Radical Polymerization ◽  
Polymer Brushes ◽  
Silicone Oil ◽  
Polymer Chains ◽  
Butyl Methacrylate ◽  
Raman Shift ◽  
Stimuli Responsive ◽  
Grafted Polymer

This study reports the utilization of controlled radical polymerization as a tool for controlling the stimuli-responsive capabilities of graphene oxide (GO) based hybrid systems. Various polymer brushes with controlled molecular weight and narrow molecular weight distribution were grafted from the GO surface by surface-initiated atom transfer radical polymerization (SI-ATRP). The modification of GO with poly(n-butyl methacrylate) (PBMA), poly(glycidyl methacrylate) (PGMA), poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) and poly(methyl methacrylate) (PMMA) was confirmed by thermogravimetric analysis (TGA) coupled with online Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Various grafting densities of GO-based materials were investigated, and conductivity was elucidated using a four-point probe method. Raman shift and XPS were used to confirm the reduction of surface properties of the GO particles during SI-ATRP. The contact angle measurements indicated the changes in the compatibility of GOs with silicone oil, depending on the structure of the grafted polymer chains. The compatibility of the GOs with poly(dimethylsiloxane) was also investigated using steady shear rheology. The tunability of the electrorheological, as well as the photo-actuation capability, was investigated. It was shown that in addition to the modification of conductivity, the dipole moment of the pendant groups of the grafted polymer chains also plays an important role in the electrorheological (ER) performance. The compatibility of the particles with the polymer matrix, and thus proper particles dispersibility, is the most important factor for the photo-actuation efficiency. The plasticizing effect of the GO-polymer hybrid filler also has a crucial impact on the matrix stiffness and thus the ability to reversibly respond to the external light stimulation.

The effect of blob size in polymer networks on nanoparticle-mediated adhesion of hydrogels

Soft Matter ◽  
2019 ◽  
Vol 15 (48) ◽  
pp. 9942-9948
Author(s):  
Sohyun Kim ◽  
Tae Hui Kang ◽  
Gi-Ra Yi
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Pore Diameter ◽  
Physical Adsorption ◽  
Mesoporous Silica Nanoparticles ◽  
Polymer Networks ◽  
Mesh Size ◽  
Adhesion Energy ◽  
Polymer Chains

Mesoporous silica nanoparticles can be used as an adhesive for hydrogels due to their physical adsorption to polymer chains, in which adhesion energy can be affected by the ratio of mesh size and pore diameter.

scholarly journals Simulation of Stimuli-Responsive Polymer Networks

Chemosensors ◽  
2013 ◽  
Vol 1 (3) ◽  
pp. 43-67 ◽  
Author(s):  
Thomas Gruhn ◽  
Heike Emmerich
Keyword(s):  
Polymer Networks ◽  
Stimuli Responsive ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer

Thermodynamic properties of swollen polymer networks containing free polymer chains

1995 ◽  
Vol 101 ◽  
pp. 159
Author(s):  
Ferenc Horkay ◽  
Anne-Marie Hecht ◽  
Erik Geissler
Keyword(s):  
Thermodynamic Properties ◽  
Polymer Networks ◽  
Polymer Chains

Surface and kinetic effects in gas chromatographic studies of polystyrene

1976 ◽  
Vol 54 (22) ◽  
pp. 3496-3507 ◽  
Author(s):  
Gregory J. Courval ◽  
Derek G. Gray
Keyword(s):  
Sample Size ◽  
Flow Rate ◽  
Retention Volume ◽  
Rate Dependence ◽  
Retention Data ◽  
Scanning Electron Micrographs ◽  
Linear Absorption ◽  
Solvent Interactions ◽  
Non Linear ◽  
Polymer Solvent

Considerable variation in the measurement of polymer–solvent interactions using gc retention data may occur due to kinetic factors, surface excess concentrations of probe vapour, and non-linear partition isotherms. The kinetic factors, which appear as a flow rate dependence of the retention volume, are analysed in terms of a previously reported theoretical model for retention on polymeric stationary phases passing through the glass transition. The predicted linear extrapolations to zero flow rate are obtained for the retention of n-tetradecane on polystyrene. The variation of this flow rate dependence with temperature and with the thickness of the stationary phase are also in qualitative agreement with the theory. A simplified model for the effect of loading on the retention diagram is presented. Non-linear absorption and bulk sorption isotherms result in a dependence of retention volume on sample size, necessitating an extrapolation of the measured retention volumes to zero peak height. The temperature variation of the flow rate dependence, the effect of loading, and the effect of sample size on retention volume are all further complicated by uneven distribution of polymer on support. From scanning electron micrographs of the beads it is evident that 'beading up' of the polystyrene on the glass surface may occur at low loadings, resulting in a non-uniform coating with large areas of the beads uncoated. It is concluded that in order to obtain reliable data on polymer–solvent interactions using gas chromatography, all of the above-mentioned factors must be considered.

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