Thermosensitive nanoparticles were prepared via the self-assembly of two different poly(ε-caprolactone)-based block copolymers of poly(N-isopropylacrylamide)-b-poly(ε-caprolactone) (PNPCL) and poly(ethylene glycol)-b-poly(ε-caprolactone) (PEGCL). The self-aggregation and thermosensitive behaviors of the mixed nanoparticles were investigated using 1H-NMR, turbidimetry, differential scanning micr...

Fast infrared mapping with sub-millimeter lateral resolution as well as time-resolved infrared studies of kinetic processes of functional organic thin films require a new generation of infrared ellipsometers. We present a novel laboratory-based infrared (IR) laser mapping ellipsometer, in which a laser is coupled to a variableangle rotating analyzer ellipsometer. Compared to conventional Fourie...

We report multi-responsive and double-folding bilayer hydrogel sheet actuators, whose directional bending response is tuned by modulating the solvent quality and temperature and where locally crosslinked regions, induced by ionoprinting, enable the actuators to invert their bending axis. The sheets are made multi-responsive by combining two stimuli responsive gels that incur opposing and comple...

A method for direct visualization of the position of nanoscale colloidal particles at air-water interfaces is presented. After assembling hard (polystyrene, poly(methyl methacrylate), silica) or soft core-shell gold-hydrogel composite (Au@PNiPAAm) colloids at the air-water interface, butylcyanoacrylate is introduced to the interface via the gas phase. Upon contact with water, an anionic polymer...

The UV radiation method is a suitable method for grafting processes. Poly-N-isopropylacrylamide was successfully grafted onto a polystyrene surface with benzophenone initiator under UV radiation. In this study, grafted polystyrene was exposed to microwave plasma treatment with oxygen gas. The ATR-FTIR analysis showed the existence of the graft poly-N-isopropylacrylamide (PNIPAAm) on the surface...

Point-of-care diagnostics for resource limited settings is a much-researched application of microfluidics technology due to its great potential. Unfortunately, one of the current limitations is the difficulty in creating tools that are both inexpensive and simple to use but also able to perform complex tasks. Light-governed microfluidic systems are of interest because, in principle, sunlight co...

We tuned the lower critical solution temperature (LCST) of amphiphilic poly(N-isopropylacrylamide) (PNIPAAm) via copolymerization with a hydrophilic comonomer of N-hydroxymethyl acrylamide (NHMAAm). A series of copolymers P(NIPAAm-co-NHMAAm) were synthesized by atom transfer radical polymerization (ATRP) using CuBr/(N,N,N',N',N''-Pentamethyldiethylenetriamine) (PMDETA) as a catalyst system and ...

Autonomic materials are those that automatically respond to a change in environmental conditions, such as temperature or chemical composition. While such materials hold incredible potential for a wide range of uses, their implementation is limited by the small number of fully-developed material systems. To broaden the number of available systems, we have developed a post-functionalization techn...

Stimuli-sensitive hydrogels have been intensively studied because of their potential applications in drug delivery, cell culture, and actuator design. Although hydrogels with directed unidirectional response, i.e. capable of bending actuated by different chemical components reaction in response to several stimuli including water and electric fields, these hydrogels are capable of being actuated...