Imperial College London


Faculty of EngineeringDepartment of Chemical Engineering

Reader in Particle Technology



+44 (0)20 7594 0784jerry.heng




417AACE ExtensionSouth Kensington Campus






BibTex format

author = {Li, Y and Yang, Q and Mei, RA and Cai, M and Heng, JYY and Yang, Z},
doi = {10.1021/acs.jpcb.7b05062},
journal = {Journal of Physical Chemistry B},
pages = {6766--6772},
title = {Controlling the Accumulation of Water at Oil-Solid Interfaces with Gradient Coating},
url = {},
volume = {121},
year = {2017}

RIS format (EndNote, RefMan)

AB - In this work, we demonstrate a strategy to control the accumulation of water in the oil–solid interface using a gradient coating. Gradient chemistry on glass surface is created by vapor diffusion of organosilanes, leading to a range of contact angles from 110 to 20°. Hexadecane is placed on the gradient substrate as an oil layer, forming a “water/hexadecane/gradient solid substrate” sandwich structure. During incubation, water molecules spontaneously migrate through the micrometer-thick oil layer and result in the formation of micrometer-sized water droplets at the oil–solid interface. It turns out that water droplets at more hydrophobic regions tend to be closer to a regular spherical shape, which is attributed to their higher contact angle with the hydrophobic substrate. However, along the gradient from hydrophobic to hydrophilic, the water droplets gradually form more irregular shapes, as hydrophilic surfaces pin the edges of droplets to form a distorted morphology. It indicates that more hydrophilic surfaces containing more Si–OH groups lead to a higher electrostatic interaction with water and a higher growth rate of interfacial water droplets. This work provides further insights into the mechanism of spontaneous water accumulation at oil–solid interfaces and assists in the rational design for controlling such interfacial phenomenon.
AU - Li,Y
AU - Yang,Q
AU - Mei,RA
AU - Cai,M
AU - Heng,JYY
AU - Yang,Z
DO - 10.1021/acs.jpcb.7b05062
EP - 6772
PY - 2017///
SN - 1520-5207
SP - 6766
TI - Controlling the Accumulation of Water at Oil-Solid Interfaces with Gradient Coating
T2 - Journal of Physical Chemistry B
UR -
UR -
VL - 121
ER -