Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 21st October 2020 from 07:00 AM to 07:00 PM (BST).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.

All chapters
Previous chapter Next chapter

Chapter 7

Solute- and Temperature-responsive Smart Membranes Formed by Covalent Layer-by-layer Assembly

Surfaces with Hofmeister-like anion-responsive wettability were prepared by covalent layer-by-layer assembly of PNIPAM-c-PNASI with 10 and 100 nm diameter aminated silica nanoparticles on Si surfaces. Their morphologies and surface roughness were investigated in a step-wise fashion by tapping mode AFM. The roughness of the polymer nanocomposite surface was found to increase when the nanoparticles were functionalized to the substrate. Significant aggregation of the nanoparticles occurred in the process of assembling multiple layers of the copolymer and nanoparticles on the substrate. The change in surface roughness increased the contact angle of 1.2 M Na2SO4 solution on the surface by ∼40° compared to pure water. Aggregation of the polymer/nanoparticles composites plays a major role in the enlargement of the surface roughness, which leads to changes in the surface wettability. These films also show variations in the Young's modulus induced by external stimuli, where temperature variation and counter ion addition to the surrounding solution were both studied to investigate their effect, as determined by colloidal probe force microscopy. Here, the elastic modulus was found to be in the range of ∼3 MPa to 189 MPa; dependent on the exposure of the polymer composite to various temperatures, counter ions and rinsing procedures.

Publication details

Print publication date
16 Apr 2019
Copyright year
Print ISBN
ePub eISBN
From the book series:
Smart Materials Series