A novel and tailored mass spectrometry workflow is presented for the analysis of polymer biodegradation products, integrating principles from the 'omics' sciences to address the challenges of complex mixture characterization. The workflow combines methodologies from polymer analysis and metabolomics, offering a comprehensive approach to data acquisition and processing, with practical considerations for user implementation. Central to the analytical strategy is the application of Kendrick Mass Defect (KMD) theory, which enhances spectral visualization and facilitates the identification of biodegradation products and metabolites within heterogeneous samples. By combining accessible and open software tools along with custom R scripts, the workflow supports reproducible MS data analysis, providing a platform for advancing polymer biodegradation research. Biodegraded samples, due to their complex polymer and metabolite content, typically generate noisy spectra, which require intensive filtering to distinguish polymer fragments from microbial metabolites. While pure polymer spectra are generally cleaner, they still necessitate specific peak detection methods, emphasizing the need for tailored data processing protocols.

Nanocomposite films combining organic semiconductors (OSCs) and colloidal quantum dots (QDs) are promising systems for next-generation optoelectronic technologies such as singlet-fission photon multiplication (SF-PM). Here, we show that tuning the solubilizing substituents on the high-triplet-energy SF-OSC (1E,3E,5E)-1,6-diphenylhexa-1,3,5-triene (DPH) enables precise control over film morphology and QD dispersibility. Grazing-incidence X-ray scattering reveals that PbS QDs ligated with oleic acid are poorly dispersed in all DPH derivatives, whereas hexanoic acid or DPH-carboxylic acid ligands significantly improve QD dispersibility. A clear design rule emerges: increasing solubilizing group volume relative to the DPH core enhances QD dispersibility, enabling well-dispersed QDs even in highly ordered DPH matrices. An exception arises in a derivative that forms an amorphous, nonequilibrium morphology that fully disperses QDs, but later crystallizes, resulting in QD aggregation. These findings show that OSC:QD nanocomposites require co-optimization of ligand-OSC chemistry and crystallization kinetics, providing a framework for designing efficient SF-PM and related technologies.

Introduction Increasing adoption of hydroponics in food production has increased the demand for soilless growing media. Given the variety of crops and cultivation techniques used in soilless systems, optimising the physical properties of novel media for specific crops and systems presents an opportunity, as some growing media, such as mineral wool, provide only a limited set of physical properties. Polyurethane foams (PUFs), a promising soilless growing media, offer flexibility, as foams with a diverse range of physical properties can be produced.Methods We examined 10 distinct PUF formulations with a range of physical properties (cell size [d], open cell fraction [peff], maximum water uptake height [Hmax], water uptake rate [Wur]) through germination and growth trials. Additionally, investigations into whether these media influence disease susceptibility were conducted by inoculating tomato plants with Pythium spp.Results and discussion Germination trials using lettuce and tomato identified four PUF formulations as unsuitable. A small-scale growth trial demonstrated that the remaining formulations performed comparably to mineral wool (MW). Three of these formulations were tested in trials for lettuce and pak choi in a NFT system and for tomato using a dripper-fed system. Results indicated that two PUF formulations surpassed MW in vegetative growth in tomato trials (F04: d = 669 mu m, peff = 0.694, Hmax = 2.94 cm, Wur = 0.023 cm s-1; F08: d = 624 mu m, peff = 0.38, Hmax = 2.35 cm, Wur = 0.012 cm s-1) and two PUF formulations matched MW in lettuce yield in NFT trials (F04: properties detailed above; F07: d = 683 mu m, peff = 0.897, Hmax = 3.07 cm, Wur = 0.055 cm s-1). Pak choi plants in foam displayed slightly lower yields than those in MW, although differences were not significant. All foam samples suppressed Pythium inoculation, as evidenced by no reduction in germination rates or seedling mass when compared to the uninoculated samples, warranting further investigation into disease suppression. These growth results suggest that growing media physical properties should be optimised according to both hydroponic technique and crop to maximise yields and that PUF media can aid in developing tailored growing media for specific crop and systems.

Polyisocyanurate (PIR) foams are widely used to insulate buildings, but their performance reduces over time leading to wasted energy and higher heating costs. High molecular weight gases used to blow the foams gradually diffuse out and are replaced by air leading to an increase in thermal conductivity. A wide variety of additives have been tested to improve the barrier properties of polymers including metal-organic frameworks (MOFs) which have proved promising candidates thanks to their tunable surface chemistry. In this work, a new and robust method for determining gas loss from rigid PIR foams has been developed, and utilised to determine the effect of different MOF additives on gas loss. An accelerated ageing method was developed, in which the mass of a fixed volume of foam was kept in an oven at 70 degrees C and weighed at 24 hour time intervals. This was found to provide reproducible measurements of gas loss over a period of 28 days with a variation of 1.1% by mass for typical samples. Five different MOFs were added to polyisocyanurates, and their effects on cell size, closed cell content, and gas loss over time were measured. Cu(ABDC)(DMF) was found to enhance the gas retention of PIR foams with minimal change to cell size or closed cell content. A modulated (flower-like) NH2-MIL-53 MOF increased the closed cell fraction whilst reducing cell size, with no effect on gas loss, whilst an unmodulated (cube like) NH2-MIL-53 MOF increased the gas loss without affecting cell size or closed cell percentage. Two further MOFs, Cu(BTetC)(DMF) and Cu(BDC)(DMF), were found to have no effect. This work therefore identifies Cu(ABDC)(DMF) as a promising additive for reducing gas-loss and maintaining the long-term performance in PIR foams, with its effectiveness demonstrated via an accelerated ageing technique developed for this study.

Reuse packaging systems (both return and refill) are a key part of achieving a circular economy, however adoption and uptake are low. A reuse system must be environmentally beneficial, economically viable and acceptable to users such that they are willing to use, and reuse, the system. Here we focus on returnable takeaway food containers and develop a methodology that combines simulating wear associated with use, assessments of consumer willingness to reuse worn containers, and quantitative life cycle assessment (LCA). The findings suggest that environmental break-even points may be lower than the number of times people are willing to use a worn container. Factors such as the design of containers and washing can be improved through lightweighting and use of renewable energy, and behavioural interventions can be delivered to increase willingness. Such interdisciplinary research enables careful system design to ensure that reuse systems confer environmental benefit.

A range of charge-stabilized aqueous polyurethane (PU) dispersions comprising hard segments formed from hydrogenated methylene diphenyl diisocyanate (H12MDI) with dimethylolpropionic acid (DMPA) and ethylenediamine, and soft segments of poly(tetramethylene oxide) of different molecular weights are synthesized. Characterization of the dispersions by mass spectrometry, gel permeation chromatography, small-angle X-ray scattering, atomic force microscopy, and infrared spectroscopy shows that they are composed of PUs self-assembled into spherical particles (primary population) and supramolecular structures formed by hydrogen-bonded H12MDI and DMPA acid-rich fragments (secondary population). Analysis of the scattering patterns of the dispersions, using a structural model based on conservation of mass, reveals that the proportion of supramolecular structures increases with DMPA content. It is also found that the PU particle radius follows the predictions of the particle surface charge density model, originally developed for acrylic statistical copolymers, and is controlled by hydrophile (DMPA) content in the PU molecules, where an increase in PU acidity results in a decrease in particle size. Moreover, there is a critical fractional coverage of hydrophiles stabilizing the particle surface for a given polyether soft-segment molecular weight, which increases with the polyether molecular weight, confirming that more acid groups are required to stabilize a more hydrophobic composition.

We report a new one-pot low-viscosity synthetic route to high molecular weight non-ionic water-soluble polymers based on polymerization-induced self-assembly (PISA). The RAFT aqueous dispersion polymerization of N-acryloylmorpholine (NAM) is conducted at 30 degrees C using a suitable redox initiator and a poly(2-hydroxyethyl acrylamide) (PHEAC) precursor in the presence of 0.60 M ammonium sulfate. This relatively low level of added electrolyte is sufficient to salt out the PNAM block, while steric stabilization is conferred by the relatively short salt-tolerant PHEAC block. A mean degree of polymerization (DP) of up to 6000 was targeted for the PNAM block, and high NAM conversions (>96%) were obtained in all cases. On dilution with deionized water, the as-synthesized sterically stabilized particles undergo dissociation to afford molecularly dissolved chains, as judged by dynamic light scattering and H-1 NMR spectroscopy studies. DMF GPC analysis confirmed a high chain extension efficiency for the PHEAC precursor, but relatively broad molecular weight distributions were observed for the PHEAC-PNAM diblock copolymer chains (M-w/M-n > 1.9). This has been observed for many other PISA formulations when targeting high core-forming block DPs and is tentatively attributed to chain transfer to polymer, which is well known for polyacrylamide-based polymers. In fact, relatively high dispersities are actually desirable if such copolymers are to be used as viscosity modifiers because solution viscosity correlates closely with M-w. Static light scattering studies were also conducted, with a Zimm plot indicating an absolute M-w of approximately 2.5 x 10(6) g mol(-1) when targeting a PNAM DP of 6000. Finally, it is emphasized that targeting such high DPs leads to a sulfur content for this latter formulation of just 23 ppm, which minimizes the cost, color, and malodor associated with the organosulfur RAFT agent.

Blends comprising organic semiconductors and inorganic quantum dots (QDs) are relevant for many optoelectronic applications and devices. However, the individual components in organic-QD blends have a strong tendency to aggregate and phase-separate during film processing, compromising both their structural and electronic properties. Here, we demonstrate a QD surface engineering approach using electronically active, highly soluble semiconductor ligands that are matched to the organic semiconductor host material to achieve well-dispersed inorganic-organic blend films, as characterized by X-ray and neutron scattering, and electron microscopies. This approach preserves the electronic properties of the organic and QD phases and also creates an optimized interface between them. We exemplify this in two emerging applications, singlet-fission-based photon multiplication (SF-PM) and triplet-triplet annihilation-based photon upconversion (TTA-UC). Steady-state and time-resolved optical spectroscopy shows that triplet excitons can be transferred with near unity efficiently across the organic-inorganic interface, while the organic films maintain efficient SF (190% yield) in the organic phase. By changing the relative energy between organic and inorganic components, yellow upconverted emission is observed upon 790 nm NIR excitation. Overall, we provide a highly versatile approach to overcome longstanding challenges in the blending of organic semiconductors with QDs that have relevance for many optical and optoelectronic applications.

Organic-inorganic nanocomposite films formed from blends of small-molecule organic semiconductors and colloidal quantum dots are attractive candidates for high efficiency, low-cost solar energy harvesting devices. Understanding and controlling the self-assembly of the resulting organic-inorganic nanocomposite films is crucial in optimising device performance, not only at a lab-scale but for large-scale, high-throughput printing and coating methods. Here, in situ grazing incidence X-ray scattering (GIXS) gives direct insights into how small-molecule organic semiconductors and colloidal quantum dots self-assemble during blade coating. Results show that for two blends separated only by a small difference in the structure of the small molecule forming the organic phase, crystallisation may proceed down two distinct routes. It either occurs spontaneously or is mediated by the formation of quantum dot aggregates. Irrespective of the initial crystallisation route, the small-molecule crystallisation acts to exclude the quantum dot inclusions from the growing crystalline matrix phase. These results provide important fundamental understanding of structure formation in nanocomposite films of organic small molecules and colloidal quantum dots prepared via solution processing routes. It highlights the fundamental difference to structural evolution which can be made by seemingly small changes in system composition. It provides routes for the structural design and optimisation of solution-processed nanocomposites that are compatible with the large-scale deposition manufacturing techniques that are crucial in driving their wider adoption in energy harvesting applications.

Controlling the dispersibility of nanocrystalline inorganic quantum dots (QDs) within organic semiconductor (OSC):QD nanocomposite films is critical for a wide range of optoelectronic devices. This work demonstrates how small changes to the OSC host molecule can have a dramatic detrimental effect on QD dispersibility within the host organic semiconductor matrix as quantified by grazing incidence X-ray scattering. It is commonplace to modify QD surface chemistry to enhance QD dispersibility within an OSC host. Here, an alternative route toward optimizing QD dispersibilities is demonstrated, which dramatically improves QD dispersibilities through blending two different OSCs to form a fully mixed OSC matrix phase.

Terrestrial controlled environment agriculture (CEA) will have an increasingly important role in food production. However, present CEA systems are energy- and resource-hungry and rarely profitable, requiring a step change in design and optimization. Here we argue that the unique nature of space controlled environment agriculture (SpaCEA), which needs to be both highly resource efficient and circular in design, presents an opportunity to develop intrinsically circular CEA systems. Life-cycle analysis tools should be used to optimize the provision and use of natural or electrical light, power, nutrients and infrastructure in CEA and/or SpaCEA systems, and to guide research and development into subsystems that bring strong environmental advantages. We suggest that SpaCEA public outreach can also be used to improve the perception of terrestrial CEA on Earth by using space as a gateway for exhibiting CEA food growing technologies. A substantial focus on SpaCEA development should be viewed as an efficient contribution to addressing major current CEA challenges.

A combination of statistical and triblock copolymer properties is explored to produce stable aqueous polymer dispersions suitable for the film formation. In order to perform an extensive structural characterization of the products in the dissolved, dispersed, and solid states, a wide range of symmetrical poly(acrylic acid-stat-styrene) x -block-poly(butyl acrylate) y -block-poly(acrylic acid-stat-styrene) x , poly(AA-st-St) x -b-PBA y -b-poly(AA-st-St) x , (x = 56, 108 and 140, y = 100-750; the AA:St molar ratio is 42:58) triblock copolymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) solution polymerization using a bifunctional symmetrical RAFT agent. It is demonstrated that the amphiphilic statistical outer blocks can provide sufficient stabilization to largely hydrophobic particles in aqueous dispersions. Such a molecular design provides an advantage over copolymers composed only of homoblocks, as a simple variation of the statistical block component ratio provides an efficient way to control the hydrophilicity of the stabilizer block, which ultimately affects the copolymer morphology in solutions and solid films. It was found by small-angle X-ray scattering (SAXS) that the copolymers behaved as dissolved chains in methylethylketone (MEK) but self-assembled in water into stable and well-defined spherical particles that increased in size with the length of the hydrophobic PBA block. These particles possessed an additional particulate surface structure formed by the statistical copolymer stabilizer block, which self-folded through the hydrophobic interactions between the styrene units. SAXS and atomic force microscopy showed that the copolymer films cast from the MEK solutions formed structures predicted by self-consistent field theory for symmetrical triblock copolymers, while the aqueous dispersions formed structural morphologies similar to a close-packed spheres, as would be expected for copolymer particles trapped kinetically due to the restricted movement of the blocks in the initial aqueous dispersion. A strong correlation between the structural morphology and mechanical properties of the films was observed. It was found that the properties of the solvent cast films were highly dependent on the ratios of the hard [poly(AA-st-St)] and soft (PBA) blocks, while the aqueous cast films did not show such a dependence. The continuous phase of hard blocks, always formed in the case of the aqueous cast films, produced films with a higher elastic modulus and a lower extension-to-break in a comparison with the solvent-cast films.

Adiabatic temperature rise is an important method for determining isocyanate conversion in polyurethane foam reactions as well as many other exothermic chemical reactions. Adiabatic temperature rise can be used in conjunction with change in height and mass measurements to gain understanding into the blowing and gelling reactions that occur during polyurethane foaming as well as give important information on cell morphology. FoamPi is an open-source Raspberry Pi device for monitoring polyurethane foaming reactions. The device effectively monitors temperature rise, change in foam height as well as changes in the mass during the reaction. Three Python scripts are also presented. The first logs raw data during the reaction. The second corrects temperature data such that it can be used in adiabatic temperature rise reactions for calculating isocyanate conversion; additionally this script reduces noise in all the data and removes erroneous readings. The final script extracts important information from the corrected data such as maximum temperature change and maximum height change as well as the time to reach these points. Commercial examples of such equipment exist however the price (>£10000) of these equipment make these systems inaccessible for many research laboratories. The FoamPi build presented is inexpensive (£350) and test examples are shown here to indicate the reproducibility of results as well as precision of the FoamPi.

Quantum dot (QD) solids are an emerging platform for developing a range of optoelectronic devices. Thus, understanding exciton dynamics is essential towards developing and optimizing QD devices. Here, using transient absorption microscopy, we reveal the initial exciton dynamics in QDs with femtosecond timescales. We observe high exciton diffusivity (~102 cm2 s-1) in lead chalcogenide QDs within the first few hundred femtoseconds after photoexcitation followed by a transition to a slower regime (~10-1-1 cm2 s-1). QD solids with larger interdot distances exhibit higher initial diffusivity and a delayed transition to the slower regime, while higher QD packing density and heterogeneity accelerate this transition. The fast transport regime occurs only in materials with exciton Bohr radii much larger than the QD sizes, suggesting the transport of delocalized excitons in this regime and a transition to slower transport governed by exciton localization. These findings suggest routes to control the optoelectronic properties of QD solids.

Abstract For decades, polymers have offered a unique combination of low cost and high durability, and are the material of choice for a huge range of applications. In the current energy system, such polymers require the combustion of fossil resources to provide process heat and electricity for manufacture, and release emissions from embodied resources when incinerated. Polymers which are biodegradable or based on biological feedstock avoid some of this resource use, but in some cases have greater energy requirements than fossil polymer equivalents. This work compares life cycle greenhouse gas emissions for pairs of fossil- and biologically-based polymers under various UK electricity, heat and end-of-life treatment scenarios between 2019 and 2040. As specific emissions from electricity and heat supply reduce over the period, life cycle emissions of all polymers fall. Polylactic acid was found to already have lower emissions than polystyrene in most scenarios. Low-density polyethylene was found to have lower emissions than poly(butylene adipate‐co‐terephthalate) in all cases to 2040. Both bio-based high density polyethylene and bio-based polyethylene terephthalate were found to have lower emissions than their fossil equivalents at some point between 2019 and 2040, depending on energy and end-of-life scenarios. Identifying and acting on these crossover points offers a route to significant reductions in the emissions of polymers, and even suggests that polymers with net negative emissions can be manufactured by 2040, offering the possibility of greenhouse gas sequestration through polymers made from agricultural waste.