Spontaneous MXene monolayer assembly at the liquid-air interface

D I Petukhov; A P Chumakov; A S Kan; V A Lebedev; Artem A Eliseev; O V Konovalov; Andrei A Eliseev

doi:10.1039/c9nr00525k

Spontaneous MXene monolayer assembly at the liquid-air interface

Nanoscale. 2019 May 28;11(20):9980-9986. doi: 10.1039/c9nr00525k. Epub 2019 May 10.

Authors

D I Petukhov¹, A P Chumakov², A S Kan³, V A Lebedev³, Artem A Eliseev¹, O V Konovalov², Andrei A Eliseev⁴

Affiliations

¹ Department of Chemistry, Lomonosov Moscow State University, Leninskiye gory 1-3, Moscow, 119991, Russia and Department of Materials Science, Lomonosov Moscow State University, 1-73 Leninskiye gory, Moscow, 119991, Russia.
² ESRF - The European Synchrotron. 71, Avenue des Martyrs, 38043 Grenoble, France.
³ Department of Chemistry, Lomonosov Moscow State University, Leninskiye gory 1-3, Moscow, 119991, Russia.
⁴ Department of Materials Science, Lomonosov Moscow State University, 1-73 Leninskiye gory, Moscow, 119991, Russia.

PMID: 31074468
DOI: 10.1039/c9nr00525k

Abstract

Here we report on the spontaneous assembly of Ti₃C₂T_x MXene flakes into monolayer films at the liquid-air interface. According to X-ray reflectivity and grazing incidence X-ray fluorescence both the structure of the layers and assembly kinetics depends on the pH value of the solution. At pH > 4 MXene flakes form a single ∼1.5 nm thick layer carrying a negative charge, while in the acidic medium the layer contains coordinated anions with the formation of the Br_aq^-/Ti₃C₂T_x/subphase interface. The surface layer compression allows the assembling of MXene flakes into a dense monolayer films with the surface coverage of up to 96% and surface pressure exceeding 40 mN m^-1 in the case of the acidic subphase. The films can readily be transferred onto solid substrates by the conventional Langmuir-Blodgett approach or modified by surfactants to form MXene/surfactant composite films.