A Patterned Butyl Methacrylate-co-2-Hydroxyethyl Acrylate Copolymer with Softening Surface and Swelling Capacity

Abstract

The tunable swelling and mechanical properties of nanostructures polymers are crucial parameters for the creation of adaptive devices to be used in diverse fields, such as drug delivery, nanomedicine, and tissue engineering. We present the use of anodic aluminum oxide templates as a nanoreactor to copolymerize butyl methacrylate and 2-hydroxyethyl acrylate under radical conditions. The copolymer obtained under confinement showed significant differences with respect to the same copolymer obtained in bulk conditions. Molecular weights, molecular weight dispersities, Young’s modulus, and wetting behaviors were significantly modified. The combination of selected monomers allowed us to obtain nanopillar structures with an interesting softening surface and extraordinary swelling capacity that could be of special interest to surface science and specifically, cell culture.

Reactivity Ratios and Surface Properties of Confined and Bulk ATRP Copolymerization of Butyl Methacrylate and 2-Hydroxyethyl Acrylate

“…Figure A illustrates the AFM topography images (1 μm × 1 μm) of the BMA 0.9 –HEA 0.1 copolymer measured in a dry and aqueous environment (the sample had been kept in water before reaching the swelling equilibrium). As previously described, water influence on the nanopillar sizes can be observed. The swelling effect of these nanomaterials exhibited an important size variation, as measured from vertical profiles of the AFM images.…”

“…34 In a previous study, with the use of free-radical copolymerization, we designed and synthesized a copolymer based on butyl methacrylate (BMA) and 2-hydroxyethyl acrylate (HEA) in only one composition under bulk and confined conditions using AAO templates. 35 The confined copolymer showed significant differences with respect to the same copolymer obtained in bulk. Molecular weight (MW), polydispersity index (PDI), Young's modulus, and wetting behavior were significantly modified.…”

In Situ Synthesis of Poly(butyl methacrylate) in Anodic Aluminum Oxide Nanoreactors by Radical Polymerization: A Comparative Kinetics Analysis by Differential Scanning Calorimetry and 1H-NMR

“…PBMA nanostructures of 350 nm of diameter and 1 µm of length, in aqueous medium under swollen conditions, shows a Gaussian distribution of the Young’s modulus, with a value of 3.1 ± 1.1 MPa [ 42 , 55 ]. Nanopillars present low elastic value and it can be explained in terms of thermosensitive behavior of the polymer.…”

“…Nanopillars present low elastic value and it can be explained in terms of thermosensitive behavior of the polymer. According to the literature, this polymer is especially sensitive to temperature, being room temperature a key point at which the elastic-plastic properties of the polymer change abruptly [ 42 , 55 , 56 , 57 , 58 ]. In fact, as previously observed by us and reported in literature, the Tg lies within the range of 20–30 °C, so that at room temperature, the polymer is just in the transition interval to a soft material.…”

“…The results of the contact angle measurement for the bulk BMA polymer show a hydrophobic character of the material (93 ± 3°). Then, PBMA homopolymer nanostructured combined with a hydrophilic polymer like 2-hydroxyethyl acrylate would form a substantially complementary material [ 42 , 55 ].…”