Multicompartment thermoresponsive gels: Does the length of the hydrophobic side group matter?

Multicompartment thermoresponsive gels are novel materials with fascinating self-assembly and interesting applications. The aim of this study was to investigate for the first time the effect of the length of the alkyl side group of a hydrophobic monomer on the thermoresponsive and self-assembly behaviour of terpolymers. Specifically twelve well-defined terpolymers based on the hydrophilic monomers 2-(dimethylamino)ethyl methacrylate (DMAEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA), and on the hydrophobic monomer ethyl-, n-butyl or n-hexyl methacrylate (EtMA, BuMA or HMA) of varying architectures (ABC, ACB, BAC and statistical) were synthesised using Group Transfer Polymerisation. The A, B and C blocks were based on PEGMA, the alkyl containing methacrylate monomer, and DMAEMA, respectively. The molecular weights (MWs) and compositions of the polymers were kept the same. The polymers and their precursors were characterised in terms of their MWs, MW distributions and compositions. Aqueous solutions of the polymers were studied by turbidimetry, hydrogen ion titration, light scattering and rheology to determine their cloud points, pKas, hydrodynamic diameters and thermoresponsive behaviour and investigate the effect of the architecture and the hydrophobic alkyl side group of the terpolymers. It was found that the pKas and the Tgs were mostly affected by the hydrophobicity of the side groups and not by the architecture, while the cloud points and the sol-gel transition of the polymers were affected by both the length of the alkyl side group and the polymer architecture. Interestingly the sharpest sol-gel transitions and stable multicompartment hydrogels were observed for the ABC triblock copolymers with the short alkyl-side groups even though the sol-gel transition occurred at higher temperatures

Urban encounters: juxtapositions of difference and the communicative interface of global cities

This article explores the communicative interface of global cities, especially as it is shaped in the juxtapositions of difference in culturally diverse urban neighbourhoods. These urban zones present powerful examples, where different groups live cheek by jowl, in close proximity and in intimate interaction — desired or unavoidable. In these urban locations, the need to manage difference is synonymous to making them liveable and one's own. In seeking (and sometimes finding) a location in the city and a location in the world, urban dwellers shape their communication practices as forms of everyday, mundane and bottom-up tactics for the management of diversity. The article looks at three particular areas where cultural diversity and urban communication practices come together into meaningful political and cultural relations for a sustainable cosmopolitan life: citizenship, imagination and identity

Microfluidically fabricated pH-responsive anionic amphiphilic microgels for drug release

© 2016 The Royal Society of Chemistry. Amphiphilic microgels of different composition based on the hydrophilic, pH-responsive acrylic acid (AA) and the hydrophobic, non-ionic n-butyl acrylate (BuA) were synthesised using a lab-on-a-chip device. Hydrophobic droplets were generated via a microfluidic platform that contained a protected form of AA, BuA, the hydrophobic crosslinker, ethylene glycol dimethacrylate (EGDMA), and a free radical initiator in an organic solvent. These hydrophobic droplets were photopolymerised within the microfluidic channels and subsequently hydrolysed, enabling an integrated platform for the rapid, automated, and in situ production of anionic amphiphilic microgels. The amphiphilic microgels did not feature the conventional core-shell structure but were instead based on random amphiphilic copolymers of AA and BuA and hydrophobic crosslinks. Due to their amphiphilic nature they were able to encapsulate and deliver both hydrophobic and hydrophilic moieties. The model drug delivery and the swelling ability of the microgels were influenced by the pH of the surrounding aqueous solution and the hydrophobic content of the microgels

Tailoring pH-responsive acrylic acid microgels with hydrophobic crosslinks for drug release

Amphiphilic microgels based on the hydrophilic acrylic acid (AA) and hydrophobic crosslinks of different compositions were synthesised using a lab-on-a-chip device. The microgels were formed by polymerising hydrophobic droplets. The droplets were generated via a microfluidic platform and contained a protected form of AA, a hydrophobic crosslinker (ethylene glycol dimethacrylate, EGDMA) and a free radical initiator in an organic solvent. Following photopolymerisation and subsequent hydrolysis, AA based microgels of amphiphilic nature were produced and it was demonstrated that they can successfully deliver both hydrophilic as well as hydrophobic moieties. The model drug delivery and the swelling ability of the microgels were influenced by the pH of the aqueous solution as well as the crosslinking density and hydrophobic content of the microgels

A smartphone-based Teleradiology system

The development of a teleradiology application for remote monitoring and processing of patient image data using 2nd generation mobile devices with enhanced network services, is of extreme interest, especially when the final means of display is a smartphone, a very light and compact handheld device. In the following paper the development of applications, that are responsible for remote monitoring and processing of medical images, is investigated

The Cognitive Profiles of Poor Readers/Good Spellers and Good Readers/Poor Spellers in a Consistent Orthography: A Retrospective Analysis

Reading and spelling are closely related to each other, but empirical evidence shows that they can also dissociate. The purpose of this study was to examine the cognitive profiles of good readers/poor spellers and poor readers/good spellers in a relatively consistent orthography (Greek). One hundred forty children were administered measures of phonological awareness, rapid automatized naming, phonological short-term memory, and orthographic knowledge in grades 1 and 2. Their performance in reading and spelling was assessed in grade 4. Two small groups of children exhibited dissociation between reading and spelling: seven children were identified as poor readers/good spellers and 11 children as good readers/poor spellers. The former group experienced severe deficits in both rapid naming and phonological awareness. The latter group experienced only mild deficits in orthographic knowledge. Although inefficient orthographic knowledge affects their spelling accuracy (Greek is inconsistent in the direction of spelling), it does not impact their reading fluency because they can recognize words by relying on partial cues

The Cognitive Profiles of Poor Readers/Good Spellers and Good Readers/Poor Spellers in a Consistent Orthography: A Retrospective Analysis

Reading and spelling are closely related to each other, but empirical evidence shows that they can also dissociate. The purpose of this study was to examine the cognitive profiles of good readers/poor spellers and poor readers/good spellers in a relatively consistent orthography (Greek). One hundred forty children were administered measures of phonological awareness, rapid automatized naming, phonological short-term memory, and orthographic knowledge in grades 1 and 2. Their performance in reading and spelling was assessed in grade 4. Two small groups of children exhibited dissociation between reading and spelling: seven children were identified as poor readers/good spellers and 11 children as good readers/poor spellers. The former group experienced severe deficits in both rapid naming and phonological awareness. The latter group experienced only mild deficits in orthographic knowledge. Although inefficient orthographic knowledge affects their spelling accuracy (Greek is inconsistent in the direction of spelling), it does not impact their reading fluency because they can recognize words by relying on partial cues

Transmission and Reflection in the Stadium Billiard: Time-dependent asymmetric transport

We investigate the transmission and reflection survival probabilities for the chaotic stadium billiard with two holes placed asymmetrically. Classically, these distributions are shown to have algebraic or exponential decays depending on the choice of injecting hole and exact expressions are given for the first time and confirmed numerically. As there is no reported quantum theoretical or experimental analogue we propose a model for experimental observation of the asymmetric transport using semiconductor nano-structures and comment on the relevant quantum time-scales.Comment: 4 pages, 4 figure