Crystallization of Polymers Under 1D Confinement

Temperature and Thickness Dependence of the Time Scale of Crystallization of Polymers under 1D Confinement

“…The former affects the thermostability of the crystal structure and favors the formation of crystal with flat-on configuration. , On the other hand, when a polymer chain gets in contact with another medium, e.g., a solid adsorbing wall or air, interfacial interactions come into play . The resulting gradient in materials properties along the direction normal to the interfaces can penetrate over several tens of nanometers, which alters the molecular mobility at different length scales and finally affects the crystallization process …”

“…Upon further reduction of the film thickness, the crystallization time increases more than what expected based on finite size effects. , Importantly, the tremendous increase in t cry observed below 30 nm cannot be explained in terms of a simple slowing down in segmental mobility, that is, by considering the bulk value of ξ. The large reduction in crystallization rate hints at SE exponents larger than 1.0, an exotic condition implying that long distance mass transport is more inhibited than that predicted based on measurements of segmental mobility. , This phenomenon can be ascribed to the formation of a layer of molecules irreversibly adsorbed onto the supporting interfaces. Our model permits rationalizing these experimental observations.…”

Molecular Mobility of Polymers at the Melting Transition

“…To solve this problem, one might think of broadband dielectric spectroscopy (BDS), a powerful technique commonly employed to characterize phase transitions and molecular fluctuations involved in the reorientation of dipole moments; in particular, BDS has already been successfully applied to study polymer crystallization both in bulk − and upon confinement at the nanoscale level . Despite the sensitivity of this technique, there are very few reports covering the melting process of semicrystalline polymers .…”

Swelling of star polymer thin films exposed to supercritical carbon dioxide

“…Supported polymer films exhibit physical properties that significantly deviate from bulk polymers, such as glass transition temperature, [1][2][3][4][5][6][7] physical aging, 7-14 crystallization, 7,[15][16][17][18][19][20] and diffusion, [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] because of confinement-induced alterations in the conformation and mobility of polymer chains near interfaces and free surfaces. The effects of confinement on the physical properties and dynamics of polymer films, as well as the underlying reasons, have been the focus of much scientific and technological research, owing to their potential applications in microelectronics, sensors, membranes, and coatings.…”