TY - JOUR

T1 - Langmuir layers of fullerene C60 and its mixtures with amphiphilic polymers

AU - Noskov, Boris A.

AU - Timoshen, Kirill A.

AU - Bykov, Alexey G.

N1 - Publisher Copyright: © 2020 Elsevier B.V.

PY - 2020/12/15

Y1 - 2020/12/15

N2 - The application of dilational surface rheology and optical microscopy combined with the more conventional methods of surface tensiometry, ellipsometry and atomic force microscopy shows that the properties of mixed spread layers of fullerene C60 with poly(vinylpyrrolidone) (PVP) and poly(N-isopropylacrylamide) (PNIPAM) are determined by the polymer at low surface pressures (less than the maximum value for a pure polymer monolayer) and by the fullerene at higher surface pressures. In particular, the dependences of the dynamic surface elasticity on the surface pressure for the mixed layers have two local maxima corresponding to the polymer and fullerene. These results indicate that the layer consists of two separate phases at low surface pressures below the characteristic value of the polymer displacement from the interface. Although the collapse of the fullerene layers starts at surface pressures of far less than 70 mN/m, some patches of the layers sustain surface pressures up to this value. The high stability of the fullerene spread layer and its strong adhesion to water can be explained by the hydroxylation of the fullerene molecules where they contact the water. A similar explanation of the high stability of fullerene aggregates in bulk water has been proposed recently. The fullerene layer is heterogeneous and consists mainly of surface aggregates with dimensions of approximately 40–60 nm in the X-Y plane. The local folding of the layer of these aggregates at high surface pressures (>30 mN/m) leads to the striation patterns, which are typical for the collapse of nanoparticle monolayers.

AB - The application of dilational surface rheology and optical microscopy combined with the more conventional methods of surface tensiometry, ellipsometry and atomic force microscopy shows that the properties of mixed spread layers of fullerene C60 with poly(vinylpyrrolidone) (PVP) and poly(N-isopropylacrylamide) (PNIPAM) are determined by the polymer at low surface pressures (less than the maximum value for a pure polymer monolayer) and by the fullerene at higher surface pressures. In particular, the dependences of the dynamic surface elasticity on the surface pressure for the mixed layers have two local maxima corresponding to the polymer and fullerene. These results indicate that the layer consists of two separate phases at low surface pressures below the characteristic value of the polymer displacement from the interface. Although the collapse of the fullerene layers starts at surface pressures of far less than 70 mN/m, some patches of the layers sustain surface pressures up to this value. The high stability of the fullerene spread layer and its strong adhesion to water can be explained by the hydroxylation of the fullerene molecules where they contact the water. A similar explanation of the high stability of fullerene aggregates in bulk water has been proposed recently. The fullerene layer is heterogeneous and consists mainly of surface aggregates with dimensions of approximately 40–60 nm in the X-Y plane. The local folding of the layer of these aggregates at high surface pressures (>30 mN/m) leads to the striation patterns, which are typical for the collapse of nanoparticle monolayers.

KW - фуллерены, амфифильные полимеры, поверхностнаядилатационная реология

KW - Fullerene

KW - Amphiphilic polymers

KW - Water – air interface

KW - Insoluble multilayers

KW - Layer structure and collapse

KW - Dilational surface rheology

UR - http://www.scopus.com/inward/record.url?scp=85092379420&partnerID=8YFLogxK

U2 - 10.1016/j.molliq.2020.114440

DO - 10.1016/j.molliq.2020.114440

M3 - Article

VL - 320

JO - Journal of Molecular Liquids

JF - Journal of Molecular Liquids

SN - 0167-7322

IS - Part A

M1 - 114440

ER -