TY - JOUR
T1 - Structure of interfacial liquids
T2 - X-ray scattering studies
AU - Yu, C. J.
AU - Richter, A. G.
AU - Kmetko, J.
AU - Dugan, S. W.
AU - Datta, A.
AU - Dutta, P.
PY - 2001
Y1 - 2001
N2 - We have used synchrotron x rays to study three different liquids near solid-liquid interfaces. For either ultrathin (45-90 Å) or thick (∼5000 Å) liquid films on silicon substrates, we find (on the basis of diffraction peaks or specular reflectivity data) that the molecules form 3-6 layers at the interface, with plane spacings close to the molecular dimensions. Rough surfaces and/or impurities reduce the density oscillation amplitudes. Making the liquid film very thin does not observably enhance the effect, which implies that layering is present even at an isolated interface (i.e., in a semi-infinite liquid). On the other hand, predeposited impurities diffuse away from the interface more easily if the liquid films are thick. The liquids studied are nonconducting, nonpolar, and nonreactive; the molecules are roughly spherical; and our substrate surface has no lateral structure. Thus our observations should apply to any liquid near a hard wall.
AB - We have used synchrotron x rays to study three different liquids near solid-liquid interfaces. For either ultrathin (45-90 Å) or thick (∼5000 Å) liquid films on silicon substrates, we find (on the basis of diffraction peaks or specular reflectivity data) that the molecules form 3-6 layers at the interface, with plane spacings close to the molecular dimensions. Rough surfaces and/or impurities reduce the density oscillation amplitudes. Making the liquid film very thin does not observably enhance the effect, which implies that layering is present even at an isolated interface (i.e., in a semi-infinite liquid). On the other hand, predeposited impurities diffuse away from the interface more easily if the liquid films are thick. The liquids studied are nonconducting, nonpolar, and nonreactive; the molecules are roughly spherical; and our substrate surface has no lateral structure. Thus our observations should apply to any liquid near a hard wall.
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U2 - 10.1103/PhysRevE.63.021205
DO - 10.1103/PhysRevE.63.021205
M3 - Article
C2 - 11308484
AN - SCOPUS:18344367140
SN - 1539-3755
VL - 63
SP - 1
EP - 8
JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
IS - 2 II
ER -