Plasticization in Ultrathin Polymer Films: The Role of Supporting Substrate and Annealing

Nguyen, Hung K.; Labardi, M.; Lucchesi, M.; Rolla, Pierangelo; Prevosto, D.

doi:10.1021/ma301980w

Cited by 50 publications

(50 citation statements)

References 32 publications

(121 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…15,16,54 This is also consistent with the findings in polymer thin and ultrathin films with decreasing thickness or annealing treatment. 17,[39][40][41]55 As discussed above, there is no tightly interfacial bound layer in hydrophobic silica NP-filled PVAc nanocomposites due to the absence of strong polymer−NP interactions, and polymer chains can only undergo adsorption onto the NP surfaces via weak physical bond formation between the polymers and NP surfaces. As a result, hydrophobic silica NPs merely act as reinforcing fillers and participate in occupying the free volume of the polymer chains.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Interfacial Interactions and Segmental Dynamics of Poly(vinyl acetate)/Silica Nanocomposites

Lin

Liu

et al. 2015

J. Phys. Chem. C

View full text Add to dashboard Cite

We investigate the interfacial interactions and segmental dynamics of hydrophilic and hydrophobic (calcined) silica nanoparticle (NP) filled poly(vinyl acetate) (PVAc) composites via a combination of Fourier transform infrared spectroscopy (FTIR) and broadband dielectric spectroscopy measurements. For hydrophilic silica NP filled composites, an increase in the amount of bound carbonyl groups with increasing silica loading can be noted due to hydrogen bonding interactions with hydroxyls on the NP surfaces and carbonyl groups of PVAc. It is surprising that the apparent glass transition temperature (T g ) increases very slightly (∼1 K) compared to pure PVAc, but the glass transition process becomes much broader, indicating the existence of a slower relaxation mode. In addition to the bulklike α-relaxation assigned to polymer segments away from the NP surfaces, the nanocomposites also exhibit a slower interfacial α′-relaxation by 3−4 orders of magnitude compared to bulk polymers. However, in the case of hydrophobic (calcined) silica NP filled composites, T g shifts to higher temperatures by 4−5 K even if there is the absence of strong polymer-NP interfacial interactions confirmed by the FTIR results. Consequently, the overall α-relaxation dynamics are suppressed in the presence of silica NPs, which is attributed to an increase of steric hindrance and decrease of free volume. More importantly, in the nanocomposites with high NP loadings, it is worth noting a weak physical adsorption interfacial layer for which the segmental mobility is on average slower by 1−2 orders of magnitude relative to that for bulk polymers. However, the dielectric strength and interfacial bound fraction is much smaller than that of hydrophilic silica NP filled composites, indicating the fact that physical adsorption is much weaker compared to hydrogen bonding.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Interfacial Interactions and Segmental Dynamics of Poly(vinyl acetate)/Silica Nanocomposites

Lin

Liu

et al. 2015

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…It is noted that metastable states have been observed in ultrathin polymer films as well. 34,35,63 Thermal Properties (DSC). The thermal properties of the neat Boltorn polyester polyols of the three generations and of all the nanocomposites were investigated by differential scanning calorimetry (DSC).…”

Section: Resultsmentioning

confidence: 99%

Dynamics of Hyperbranched Polymers under Confinement: A Dielectric Relaxation Study

Androulaki

Chrissopoulou

Prevosto

et al. 2015

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

The effect of severe confinement on the dynamics of three different generations of hyperbranched polyesters of the Boltorn family is investigated by dielectric relaxation spectroscopy (DRS). The polymer chains are intercalated within the galleries of natural montmorillonite (Na+-MMT), thus forming 1 nm polymer films confined between solid walls. The structure of the nanocomposites is studied with X-ray diffraction and the thermal behavior of the polymers in bulk and under confinement is determined by differential scanning calorimetry. The glass transition temperatures of the polymers show a clear dependence on the generation whereas the transition is completely suppressed when all the polymer chains are intercalated. The dynamic investigation of the bulk polymers reveals two sub-Tg processes, with similar behavior for the three polymers with the segmental relaxation observed above the Tg of each polymer. For the nanocomposites, where all the polymer chains are severely confined, the dynamics show significant differences compared to that of the bulk polymers. The sub-Tg processes are similar for the three generations but significantly faster and with weaker temperature dependence than those in the bulk. The segmental process appears at temperatures below the bulk polymer Tg, it exhibits an Arrhenius temperature dependence and shows differences for the three generations. A slow process that appears at higher temperatures is due to interfacial polarization.

show abstract

“…If we attribute this delay to the ion migration to the interface, then the roughly estimated mobility of 10 −16 –10 −17 m 2 V −1 s −1 (see Experimental Section for details) cannot be ascribed to migration of H + or OH − ions with a mobility of 10 −9 m 2 V −1 s −1 in the polymer melts, but rather to migration of bulky anions of the PolyIL. Higher humidity leads not only to a better ion solvation, but also to a reduced local viscosity due to the general effect of plasticization; so, ions diffuse faster in the PolyIL. As ions arrive at the interface, an uncompensated dense electrical charge starts to buildup.…”

Section: Resultsmentioning

confidence: 99%

Controlled Nanopatterning of a Polymerized Ionic Liquid in a Strong Electric Field

Bocharova

Agapov

Tselev

et al. 2014

Adv Funct Materials

View full text Add to dashboard Cite

Nanolithography has become a driving force in advancements of the modern day's electronics, allowing for miniaturization of devices and a steady increase of the calculation, power, and storage densities. Among various nanofabrication approaches, scanning probe techniques, including atomic force microscopy (AFM), are versatile tools for creating nanoscale patterns utilizing a range of physical stimuli such as force, heat, or electric field confined to the nanoscale. In this study, the potential of using the electric field localized at the apex of an AFM tip to induce and control changes in the mechanical properties of an ion containing polymer—a polymerized ionic liquid (PolyIL)—on a very localized scale is explored. In particular, it is demonstrated that by means of AFM, one can form topographical features on the surface of PolyIL‐based thin films with a significantly lower electric potential and power consumption as compared to nonconductive polymer materials. Furthermore, by tuning the applied voltage and ambient air humidity, control over dimensions of the formed structures is reproducibly achieved.

show abstract

Plasticization in Ultrathin Polymer Films: The Role of Supporting Substrate and Annealing

Cited by 50 publications

References 32 publications

Interfacial Interactions and Segmental Dynamics of Poly(vinyl acetate)/Silica Nanocomposites

Interfacial Interactions and Segmental Dynamics of Poly(vinyl acetate)/Silica Nanocomposites

Dynamics of Hyperbranched Polymers under Confinement: A Dielectric Relaxation Study

Controlled Nanopatterning of a Polymerized Ionic Liquid in a Strong Electric Field

Contact Info

Product

Resources

About