High chi polymers from hydrophobic initiators for ultra-small microphase separation

This work focuses on the use of copper-mediated polymerisation as a versatile method to produce low molecular weight polymers with narrow dispersity (< 3000 Da, Đ < 1.20) for the specific aim of studying their self-assembly in the solid state via microphase separation. By exploiting the theory of microphase separation of block copolymers, separated polymer phases have been achieved by maximising the Flory-Huggins interaction parameter () and minimising the total degree of polymerisation (molecular weight, N). The study of block copolymer behaviour has grown in prominence and academic interest due to applications in the microelectronics industry, which has become a significant driving force for obtaining smaller domains, as it can lead to higher density data storage. This work focusses on the synthesis of highly amphiphilic polymers produced by copper-mediated polymerisations and studying their self-assembly in the solid state. Initially an F13 initiator (perfluorooctyl bromoisobutyrate) was used as a pseudo block to minimise N and maintain high . The conditions of the polymerisation of poly(acrylic acid) using this initiator were optimised and polymer morphologies and domain sizes were inferred from Small-angle X-ray scattering (SAXS). The use of both solvent and temperature annealing show different assemblies, and thermal annealing was shown to alter the structures. The work moved onto the investigation of an F17 and F21 pseudo block (perfluorodecyl bromoisobutyrate and perfluorododecyl bromoisobutyrate), While domain sizes were found to be larger than those in F13-PAA films, F17/F21 polymers exhibited longer range order and more crystallinity. Block copolymer models were used to predict the phase behaviour of these polymers and a phase diagram was developed. Finally, the scope of hydrophobic initiators and hydrophilic monomers possible for use in the synthesis and microphase separation of high low N polymers was investigated. The polymerisation conditions were optimised for targeting low degree of polymerisation with both acrylates and methacrylates and included incorporation of additional photo-responsive properties via an anthracene end group

Dihydrolevoglucosenone (Cyrene™) as a bio-renewable solvent for Cu(0)wire-mediated reversible deactivation radical polymerization (RDRP) without external deoxygenation

Biorenewable dihydrolevoglucosenone (Cyrene™) is used as an effective dipolar aprotic solvent for Cu(0) wire-mediated RDRP of various monomers without external deoxygenation being applied

Interfacial rearrangements and strain evolution in the thin film growth of ZnPc on glass

We report on the characterization of the growth of vacuum-deposited zinc phthalocyanine (ZnPc) thin films on glass through a combination of in situ grazing incidence x-ray scattering, x-ray reflectivity, and atomic force microscopy. We found that the growth at room temperature proceeds via the formation of two structurally unique substrate-induced interfacial layers, followed by the growth of the γ-ZnPc polymorph thereafter (thickness ≈1.0 nm). As the growth of the bulk γ-ZnPc progresses, a substantial out-of-plane lattice strain (≈15% relative to γ-ZnPc powder) is continually relaxed during the thin film growth. The rate of strain relaxation was slowed after a thickness of ≈13 nm, corresponding to the transition from layer growth to island growth. The findings reveal the real-time microstructural evolution of ZnPc and highlight the importance of substrate-induced strain on thin film growth

Automatic peak assignment and visualisation of copolymer mass spectrometry data using the “genetic algorithm”

Copolymer analysis is vitally important as the materials have a wide variety of applications due to their tunable properties. Mass spectrometry data for copolymer samples can be very complex due to the increase in the number of species when the polymer chains are formed by 2 or more monomeric units. In this paper, we describe the use of the genetic algorithm for automated peak assignment of copolymers synthesised by a variety of polymerization methods. We find that in using this method we are able to easily assign copolymer spectra in a few minutes and visualise them into heatmaps. These heatmaps allowed us to look qualitatively at the distribution of the chains, showing how they alter with different polymerization techniques, and by changing the initial copolymer composition. This methodology is shown to be simple to use and requires little user input, which makes it well suited for use by less expert users. The data outputted by the automatic assignment may also allow for more complex data processing going forward

Heterotelechelic homopolymers mimicking high χ – ultralow N block copolymers with sub-2 nm domain size

Three fluorinated, hydrophobic initiators have been utilised for the synthesis of low molecular mass fluoro-poly(acrylic acid) heterotelechelic homopolymers to mimic high chi (χ)–low N diblock copolymers with ultrafine domains of sub-2 nm length scale. Polymers were obtained by a simple photoinduced copper(II)-mediated reversible-deactivation radical polymerisation (Cu-RDRP) affording low molecular mass (<3 kDa) and low dispersity (Đ = 1.04–1.21) homopolymers. Heating/cooling ramps were performed on bulk samples (ca. 250 μm thick) to obtain thermodynamically stable nanomorpologies of lamellar (LAM) or hexagonally packed cylinders (HEX), as deduced by small-angle X-ray scattering (SAXS). Construction of the experimental phase diagram alongside a detailed theoretical model demonstrated typical rod–coil block copolymer phase behaviour for these fluoro-poly(acrylic acid) homopolymers, where the fluorinated initiator-derived segment acts as a rod and the poly(acrylic acid) as a coil. This work reveals that these telechelic homopolymers mimic high χ-ultralow N diblock copolymers and enables reproducible targeting of nanomorphologies with incredibly small, tunable domain size

Correction: Microphase separation of highly amphiphilic, low N polymers by photoinduced copper-mediated polymerization, achieving sub-2 nm domains at half-pitch

Correction for ‘Microphase separation of highly amphiphilic, low N polymers by photoinduced copper-mediated polymerization, achieving sub-2 nm domains at half-pitch’ by Ellis Hancox et al., Polym. Chem., 2019, 10, 6254–6259. DOI: 10.1039/c9py01312a

Microphase separation of highly amphiphilic, low N polymers by photoinduced copper-mediated polymerization, achieving sub-2 nm domains at half-pitch

The lower limit of domain size resolution using microphase separation of short poly(acrylic acid) homopolymers equipped with a short fluorinated tail, posing as an antagonist 'A block' in pseudo AB block copolymers has been investigated. An alkyl halide initiator with a fluorocarbon chain was utilized as a first 'A block' in the synthesis of low molecular weight polymers (1400-4300 g mol -1) using photoinduced Cu(ii)-mediated polymerization allowing for very narrow dispersity. Poly(tert-butyl acrylate) was synthesized and subsequently deprotected to give very low degrees of polymerization (N), amphiphilic polymers with low dispersity (D = 1.06-1.13). By exploiting the high driving force for demixing and the well-defined 'block' sizes, we are able to control the nanostructure in terms of domain size (down to 3.4 nm full-pitch) and morphology. This work demonstrates the simple and highly controlled synthesis of polymers to push the boundaries of the smallest achievable domain sizes obtained from polymer self-assembly

UV irradiation of Cu-based complexes with aliphatic amine ligands as used in living radical polymerization

The effect UV irradiation on Cu(II)-based complexes with aliphatic amine ligands is investigated. Four aliphatic amines are used as ligands and Cu(II)Br2 as the metal source for the formation of catalyst complexes that can be used for the photoinduced Cu-RDRP of methyl acrylate. Different characterization techniques such as transient electronic absorption spectroscopy (TEAS), ultraviolet-visible (UV-Vis) spectroscopy, electrospray ionization time of flight mass spectrometry (ESI-ToF-MS) and cyclic voltammetry (CV) are applied in order to provide insights into the catalyst behaviour upon photo-irradiation. The excited-state dynamics, the electrochemical behaviour of the Cu(II)/Cu(I) redox couples and the detection of different species upon complexation of the ligand to the metal center (before and after UV irradiation) are further depicted in the quality of the obtained polymers

Global mortality and readmission rates following COPD exacerbation-related hospitalisation: a meta-analysis of 65 945 individual patients

\ua9 2024, European Respiratory Society. All rights reserved.Background Exacerbations of COPD (ECOPD) have a major impact on patients and healthcare systems across the world. Precise estimates of the global burden of ECOPD on mortality and hospital readmission are needed to inform policy makers and aid preventive strategies to mitigate this burden. The aims of the present study were to explore global in-hospital mortality, post-discharge mortality and hospital readmission rates after ECOPD-related hospitalisation using an individual patient data meta-analysis (IPDMA) design. Methods A systematic review was performed identifying studies that reported in-hospital mortality, postdischarge mortality and hospital readmission rates following ECOPD-related hospitalisation. Data analyses were conducted using a one-stage random-effects meta-analysis model. This study was conducted and reported in accordance with the PRISMA-IPD statement. Results Data of 65 945 individual patients with COPD were analysed. The pooled in-hospital mortality rate was 6.2%, pooled 30-, 90- and 365-day post-discharge mortality rates were 1.8%, 5.5% and 10.9%, respectively, and pooled 30-, 90- and 365-day hospital readmission rates were 7.1%, 12.6% and 32.1%, respectively, with noticeable variability between studies and countries. Strongest predictors of mortality and hospital readmission included noninvasive mechanical ventilation and a history of two or more ECOPD-related hospitalisation

Development and validation of a diagnostic prediction model for pancreatic ductal adenocarcinoma: VAPOR 1, protocol for a prospective multicentre case-control study

\ua9 Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY. Published by BMJ Group. Introduction: Pancreatic ductal adenocarcinoma (PDAC) continues to have extremely poor patient outcomes, unlike other cancer types which have seen significant improvements in their treatments and survival. A major contributing factor is that PDAC is often detected at an advanced, incurable stage. In the UK, nearly half of patients have stage 4 disease at the time of diagnosis, which has a profound effect on treatment options and, ultimately, survival. To address the challenge of early detection of PDAC, this study aims to develop and validate a clinical prediction model based on a non-invasive breath test. The proposed breath test aims to assist general practitioners in the triaging of patients who present with symptoms that do not meet current criteria for urgent suspected PDAC pathway referral. Methods and analysis: The Volatile organic compound Assessment in Pancreatic ductal adenOcaRcinoma (VAPOR 1) study is a prospective, multicentre, case-control study that aims to recruit 771 participants from England, Wales and Scotland. These include adult participants, aged ≥18 years, in three cohorts: pancreatic ductal adenocarcinoma; benign pancreatic controls (chronic pancreatitis or new-onset diabetes); healthy controls with a normal pancreas on imaging. A one-off breath sample will be obtained from participants who have fasted for at least 6 hours, and participant demographics and clinical data will be recorded. Breath samples will be analysed using gas chromatography-mass spectrometry to identify the volatile organic compounds (VOCs) present. Relationships between VOCs of interest and the presence of PDAC will be explored, and a clinical prediction model will be developed using statistical and machine learning methods and internally validated. Ethics and dissemination: The VAPOR 1 study has received approval from the South East Scotland Research Ethics Committee 02, and from the Health Research Authority and Health and Care Research Wales (REC 22/SS/0061). Results of this study will be published in open-access peer-reviewed journals, and disseminated through pancreatic cancer conference presentations. In addition, lay summaries shared on our website, social media platforms and through our charitable funder, Pancreatic Cancer UK, will enable engagement with patients and the wider public