CHAPTER 3
 POLYSTYRENE-b-POLY(TERT-BUTYLACRYLATE) AND POLYSTYRENE-b-
 POLY(ACRYLIC ACID) DENDRIMER-LIKE COPOLYMERS: TWO-DIMENSIONAL
 SELF-ASSEMBLY AT THE AIR-WATER INTERFACE

 3.1 Introduction

 As introduced in Chapter 1, block copolymers are of great interest for nanotechnological

applications because of their potential in forming well-defined morphologies in bulk,93 in

solution,94 Or at interfaces.95 Amphiphilic block copolymers offer good opportunities to control

interfacial properties, and since they self-assemble at hydrophilic/hydrophobic environments

such as the air/water (A/W) interface to form regular arrangements of two-dimensional surface

micelles, they are particularly interesting as precursors for the synthesis of well-defined patterns

with feature sizes typically in the nanometer scale order. The nanosized structures can be easily

controlled by varying various parameters such as the nature of the blocks, the molecular weight,

the relative lengths of the blocks, or even the block copolymer architecture. With a view toward

understanding the relationships between polymer architecture and A/W interfacial aggregation, a

variety of polystyrene-b-poly(ethylene oxide) block copolymers with simple and complex

architectures (linear, star-shaped, mikto-arm, dendrimer-like...) has been synthesized and

extensively investigated in the past few years.22,96

 Concerning polystyrene-b-poly(tert-butylacrylate) (PS-b-PtBA) and polystyrene-b-

poly(acrylic acid) (PS-b-PAA) block copolymers, only little work has been reported on their

A/W interfacial behavior. Lennox and co-workers were to our knowledge the only ones to report

on the two-dimensional surface micelle formation for PS-b-PtBA block copolymers,

investigating linear samples with relatively small PtBA chains compared to the PS block.24,97 The

self-assembly of PS-b-PAA block copolymers was also studied almost exclusively for linear

samples,20,98 and it is only very recently that Tsukruk and co-workers described the self-assembly