Influence of confinement on conformational entropy of a polymer chain and structure of polymer–nanoparticles complexes

Nowicki, Waldemar; Nowicka, Grażyna

doi:10.1016/j.polymer.2009.02.044

Cited by 17 publications

(20 citation statements)

References 55 publications

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“…Indeed, the concurrent presence of high-energy interfaces and conformational entropy constraints of the macromolecules under nanoconfined conditions causes profound differences in the aggregation behavior of the polymer131516 and can influence both its morphology and its crystallinity degree. This work aims to exploit this peculiar phase transition to induce the formation of crystallized architectures, which, at the same reactant concentrations and process conditions, are not usually formed in bulk media.…”

mentioning

confidence: 99%

Synthesis of semicrystalline nanocapsular structures obtained by Thermally Induced Phase Separation in nanoconfinement

Torino

Aruta

Sibillano

et al. 2016

Sci Rep

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Phase separation of a polymer solution exhibits a peculiar behavior when induced in a nanoconfinement. The energetic constraints introduce additional interactions between the polymer segments that reduce the number of available configurations. In our work, this effect is exploited in a one-step strategy called nanoconfined-Thermally Induced Phase Separation (nc-TIPS) to promote the crystallization of polymer chains into nanocapsular structures of controlled size and shell thickness. This is accomplished by performing a quench step of a low-concentrated PLLA-dioxane-water solution included in emulsions of mean droplet size <500 nm acting as nanodomains. The control of nanoconfinement conditions enables not only the production of nanocapsules with a minimum mean particle diameter of 70 nm but also the tunability of shell thickness and its crystallinity degree. The specific properties of the developed nanocapsular architectures have important implications on release mechanism and loading capability of hydrophilic and lipophilic payload compounds.

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mentioning

confidence: 99%

Synthesis of semicrystalline nanocapsular structures obtained by Thermally Induced Phase Separation in nanoconfinement

Torino

Aruta

Sibillano

et al. 2016

Sci Rep

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“…We will refer to this algorithm as the (011) motion: as mentioned above, the vectors connecting two following beads are of the kind (011), that is, only two of their three components are not null and they have values in absolute modulus equal to 1. This algorithm differs from the ones previously used in literature, both for polymers and for polypeptides for the maximum coordination number which each chain bead can experiment, meaning the number of sites available for the allocation of the successive bead: in this case, it is equal to 12, to reduce the chain flexibility, introducing a lower number of allowed angles between two following links connecting chain beads.…”

Section: Methodsmentioning

confidence: 99%

“…The conformational entropy of the confined and the unconfined single polymer chain is calculated using the SC method, a kind of MC method well described in literature and previously used to estimate the entropy of chains terminally attached to a surface . According to this method, the calculation of the chain conformational entropy is based on the following definition

ω (|, i) = normalΩ true(i + 1 true) / normalΩ true(i true)

where

normalΩ (|, i)

and

normalΩ true(i + 1 true)

represent the number of accessible conformations for the chain consisting of

i

and of

i + 1

beads, respectively;

ω false(i false)

can be interpreted as the number of allowed allocation for the bead

i + 1

, that is, the coordination number for the

i th

bead; as described above, we have

ω false(i false) \leq 12 normalf normalo normalr i = 1, 2, \dots, N

…”

Section: Methodsmentioning

confidence: 99%

“…In other literature works, some modifications of the classic SAW model on a cubic lattice were introduced to modulate the modeled polymer flexibility. A modification of the conventional SAW model was used to study the thermodynamic properties of a single chain in an athermal solution, in the presence of a solid obstacle, using the static MC sampling method coupled with the SC method, focusing on the excluded volume effects. However, a deep understanding of how processes involving a polymer solution, such as the phase separation system can be affected by the loss of chain conformational freedom in three dimensions is still missing.…”

Section: Introductionmentioning

confidence: 99%

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Confinement of a polymer chain: An entropic study by Monte Carlo method

et al. 2017

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The properties of macromolecules in presence of an interface could be considerably modified due to confinement effects. When phase separations are performed in nanoconfined domains, the concurrent presence of high‐energy interfaces and conformational entropy constraints of the macromolecules causes profound differences in polymer aggregation behavior. Here, thermodynamics of a polymer chain in solution, confined by a three‐dimensional cubic interface, is studied by means of Monte Carlo method, focusing on the chain conformational entropy penalty arising from the excluded volume effects. The presented method might become a general tool for a preliminary evaluation of the thermodynamic effects due to the confinement of a polymer system. Further, the interface effects on Thermally Induced Phase Separation (TIPS) of polymer solutions, confined by High‐Pressure Homogenization, are experimentally studied, regarding final morphologies. It is confirmed how peculiar polymer morphologies are obtained only when the TIPS develops under nanoconfinement degrees above a threshold one. © 2017 American Institute of Chemical Engineers AIChE J, 64: 416–426, 2018

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“…In one argument put forth by Lindenmeyer [32], the researchers proposed that the conformational entropy of a polymer chain is proportional to the number of conformations that it can adopt. If the chain approaches a substrate (i.e., a crystal or a filler), some of its conformations will be forbidden and the resulting entropy can be accordingly diminished [33][34][35].…”

Section: Non-isothermal Crystallizationmentioning

confidence: 99%

In situ polymerization of poly(styrene- alt -maleic anhydride)/organic montmorillonite nanocomposites and their ionomers as crystallization nucleating agents for poly(ethylene terephthalate)

Xing

et al. 2016

Journal of Industrial and Engineering Chemistry

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Influence of confinement on conformational entropy of a polymer chain and structure of polymer–nanoparticles complexes

Cited by 17 publications

References 55 publications

Synthesis of semicrystalline nanocapsular structures obtained by Thermally Induced Phase Separation in nanoconfinement

Synthesis of semicrystalline nanocapsular structures obtained by Thermally Induced Phase Separation in nanoconfinement

Confinement of a polymer chain: An entropic study by Monte Carlo method

In situ polymerization of poly(styrene- alt -maleic anhydride)/organic montmorillonite nanocomposites and their ionomers as crystallization nucleating agents for poly(ethylene terephthalate)

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