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Metal hollow nanostructures have a wide range of potential applications in energy storage and conversion, owing to their low density, high surface to volume ratio, and high contact surface area.

Blood apheresis technologies are crucial during blood donation and toxin removal. Current purification methods such as leukocytapheresis, erythrocytapheresis, thrombocytapheresis and plasmapheresis primarily rely on centrifugation and membrane filtration to separate blood components. Although established and scaled-up, challenges related to the selectivity and long-term impact of these techniques on blood cells and their constituents remain. Shear generated during extraction may stress blood cells leading to cell damage and initiate the complement cascade causing platelet activation or triggering inflammatory responses. Emerging technologies, including microfluidics and selective adsorption present viable alternatives supporting more selective extraction pathways but extensively rely on novel manufacturing or material developments. This review critically assesses recent progress across apheresis technologies relating to advances in surface science and materials engineering to address operating challenges towards selective removal or extraction of blood components in traditional apheresis technologies such as centrifugation and membrane filtration.

The fabrication of graphene nanostructures, with a variety of morphologies and densities of defective sites, can be a promising tool to tune their characteristics towards photocatalytic applications, without the need for external dopants. In this study, the impact of morphological properties in terms of the orientation and defect concentrations of graphene nanostructures is demonstrated to support the development of active photocatalytic sites across graphitic structures. Vertically-aligned graphene nanosheets were grown across carbon fibres via electron cyclotron resonance microwave plasma chemical vapour deposition, to yield a range of different wall densities and edge functionalities. The variation of growth conditions was correlated to the photocatalytic activity for the degradation of methylene blue dye under ultra-violet and visible light. The chemical state of oxygen content hybridized with nanosheets was studied by X-ray photoelectron spectroscopy and correlated to the growth conditions and photocatalytic performance. The fastest degradation rate of dye was found on the graphene samples which were grown at 800 °C for 240 min, with a kinetic constant of 46.6 × 10−4 min−1. Such performance has not been observed to date for any graphitic materials and is shown to be on the same order of performance as the conventional photocatalytic materials.

Atomic layer deposition (ALD) has emerged as the technique of choice in the microelectronics industry, owing to its self-limiting nature, that allows conformal film deposition in highly confined sp...

Construction workers on highway rehabilitation projects can be exposed to a combination of traffic- and construction-related emissions. To assess the personal exposure a worker experiences, a portable battery-operated Air Quality Device (AQD) was utilised to measure emissions during normal construction operations of a major road rehabilitation project. Emissions measured were nitrogen dioxide (NO

The design and fabrication of 2D nano-porous architectures with controllable porosity and pore structure, as well as unique properties at the nanoscale are critical for applications such as separation, sensing, energy and catalysis. Perforation strategies across 2D materials, primarily graphene, have shown promising opportunities to develop nanostructures with tunable ranges of pore size distribution, pore density and uniformity. In addition, the perforated graphene structures exhibit improved properties in terms of plasmonic diffusion, catalytic activity and thermo-electrical properties compared to dense 2D materials and are opening new avenues for the development of responsive or reactive materials. This review presents and discusses the very recent developments in the synthesis of perforated graphene-based materials and correlates the morphology and other properties of such 2D nano-porous materials to their performance in applications such as separation, sensing and energy. Challenges related to the controlled engineering and manufacturing of such nanostructures particularly from a scalability point of view, as well as potential avenues for performance improvements through alternative 2D perforated materials are also critically evaluated.

Nano-perforated graphene sheets have emerged as exciting two-dimensional materials for a broad range of scientific and commercial purposes, due to their modified physicochemical properties as compared to native graphene materials. Nanoporous graphene sheets as a class of two-dimensional materials with thicknesses ranging from sub-nanometre to few tens of nanometres, possess high specific surface areas and porous mesh structures with tuneable porosity levels. These properties lead to high densities of unsaturated carbon edges around the pores, making them attractive candidates for applications such as energy storage, separation, sensing or catalysis. Several perforation methodologies have been reported to sculpt pores across graphene structures via etching or guided growth mechanisms. This review focuses on current and emerging nano-perforation methodologies for the two-dimensional graphene materials, and discusses controllable porosity parameters in terms of physical pore size and surface pore density across 2D materials. The relationship between perforation methodology and the achieved porosity level is also discussed and related to electronic or surface reactivity properties. Suggestions towards perforation methodologies in relation to targeted pore size and density, as well as the current challenges hindering scalability of engineering the nanoporous graphene and other similar two-dimensional materials are also highlighted.

Photo/electrocatalytic conversion of carbon dioxide (CO2), has potential to address the adverse environmental impact of global warming. However, it is challenging to control the reactions to yield a specific product, and most catalyst produce a mixture of product that may include methanol, carbon monoxide (CO), methane among others. Metal organic frameworks (MOFs) derived carbon catalysts have potential to facilitate selective CO2 conversion, owing to their regular microporous structure, in addition to enhanced chemical stability and electrical conductivity as compared to the precursor MOFs. However, there are no established techniques for immobilizing these catalysts directly on the surface a conductive substrate, without the need of polymer adhesives. Here, MOF-derived hybrid carbon photoelectrocatalytic reactors were successfully fabricated on the surface of macroporous metal support, by direct carbonization of the metal supported MOF membranes. The carbonization resulted in a dramatic improvement in electrocatalytic performance, with samples carbonized at 700 °C producing up to 9 times higher methanol yield as compared to non-carbonized membranes. The product selectivity could also be tuned from methanol, to CO or a mixture of both, by switching between electrocatalysis and photocatalysis. This work opens route for the development of robust metal supported carbonized MOF-based catalysts, for energy conversion applications.

The integrated capture and conversion of CO

Downsizing metal–organic framework (MOF) crystals into the nanoregime offers a promising approach to further benefit from their inherent versatile pore structures and surface reactivity. In this article, downsizing is referred to as the deliberate production of typical large MOF crystals into their nanosized versions. Here, we discuss various strategies towards the formation of crystals below 100 nm and their impact on the nano-MOF crystal properties. Strategies include an adjustment of the synthesis parameters (e.g., time, temperature, and heating rate), surface modification, ligand modulation, control of solvation during crystal growth and physical grinding methods. These approaches, which are categorized into bottom-up and top-down methods, are also critically discussed and linked to the kinetics of MOF formation as well as to the homogeneity of their size distribution and crystallinity. This collection of downsizing routes allows one to tailor features of MOFs, such as the morphology, size distribution, and pore accessibility, for a particular application. This review provides an outlook on the enhanced performance of downsized MOFs along with their potential use for both existing and novel applications in a variety of disciplines, such as medical, energy, and agricultural research. Methods for enhancing the properties of porous materials known as metal–organic frameworks (MOFs) by making the crystals smaller have been reviewed by scientists in Australia and the Philippines. MOF crystals have an open atomic structure which includes large voids. MOFs are highly crystalline materials, typically generated in powder form, useful for applications such as hydrogen storage and carbon capture. Reducing the crystal sizes to nanometer scales significantly enhances the material’s physical and chemical properties. Ken Usman, Ludovic Dumee and Joselito Razal from Deakin University, Geelong, Australia, and co-workers have reviewed the latest methods for synthesizing MOF crystals smaller than a hundred nanometers. Synthesis strategies include altering a wide range of parameters such as time, temperature and heating rate. The authors show how these different approaches allow the properties of nano-sized MOF, including morphology and size distribution, to be controlled to suit a specific application. Metal organic frameworks are typically synthesized at the macroscale, into powders, films or as coatings generated across appropriate supporting materials. The downsizing of metal–organic frameworks offers opportunities to not only benefit from their properties at the nanoscale but also to enhance surface interactions and reactivities. The potential and challenges with current downsizing techniques are discussed in this review in light of materials properties and application performance.

In this study, a novel hybrid metal organic framework (MOF) – bucky-paper was developed by seeding crystal growth of Mg-MOF-74 from the surface of carbon nanotube (CNT) mats, called bucky-papers (BP). The seeding density and growth kinetics of the MOF crystals across the CNT-BPs was enhanced through continuous discharge plasma treatments with either O2/Ar or NH3 gas streams. X ray Photo-electron Spectroscopy measurements were used to demonstrate the impact of the plasma treatment on the anchoring of hydroxyl, amine and carbonyl functional groups to the graphitic surfaces, resulting in higher surface wettability and greater MOF seeding densities. CO2 adsorption isotherms at 25 °C showed a large increase in CO2 uptake (maximum of 10.70 mmol CO2/g) for MOF-CNT-BP samples compared to virgin CNT-BP (0.35 mmol CO2/g) or parent Mg-MOF-74 (maximum of 3.13 mmol CO2/g). Higher CO2 adsorption of MOF-CNT-BP sponges were attributed to the synergistic effect between the MOF and CNT due to increased porosity at the interface, better MOF crystal distribution, and enhanced dispersive forces which improve structural integrity of MOF component.

Electrocatalytic membrane reactors are becoming a viable solution for the treatment of wastewater contaminated with persistent organic pollutants and compounds. The development of suitable membrane elements made of abundant and stable electrocatalytic materials remains a challenge to enable durable and large-scale operation. In this study, novel nickel (Ni) and nickel-copper (NiCu) alloy hollow-fiber (HF) membranes were synthesized for the first time and used for the electrocatalytic degradation of small organic molecule pollutants from model wastewater effluents. The novel porous metal HFs were characterized and tested for their capacity to degrade salicylic acid (SA) molecules by electrochemical oxidation. The degradation of SA was monitored in situ and over time using an ultraviolet-visible (UV/vis) quartz cell. The HF membranes were found to be highly stable and reusable while the kinetics of SA electro-oxidation were 9 to 20 times greater than with pure platinum wire electrodes. The high performance of the HF materials was attributed to the interconnected pore structure combined with the natural surface reactivity and excellent electron transport properties of the Ni metal and bare NiCu alloy.

Fabrication of metal organic framework (MOF) films and membranes across macro-porous metal substrates is extremely challenging, due to the large pore sizes across the substrates, poor wettability, and the lack of sufficient reactive functional groups on the surface, which prevent high density nucleation of MOF crystals. Herein, macroporous stainless steel substrates (pore size 44 × 40 μm) are functionalized with amine functional groups, and the growth of ZIF-8 crystals investigated through both solvothermal synthesis and rapid thermal deposition (RTD), to assess the role of synthesis routes in the resultant membranes microstructure, and subsequently their performance. Although a high density of well interconnected MOF crystals was observed across the modified substrates following both techniques, RTD was found to be a much more efficient route, yielding high quality membranes under 1 h, as opposed to the 24 h required for solvothermal synthesis. The RTD membranes also exhibited high gas permeance, with He permeance of up to 2.954 ± 0.119 × 10 −6 mol m −2 s −1 Pa −1 , and Knudsen selectivities for He/N 2 , Ar/N 2 and CO 2 /N 2 , suggesting the membranes were almost defect free. This work opens up route for efficient fabrication of MOF films and membranes across macro-porous metal supports, with potential application in electrically mediated separation applications.

Photocatalytic conversion of carbon dioxide (CO2) to useful products has potential to address the adverse environmental impact of global warming. However, most photocatalysts used to date exhibit limited catalytic performance, due to poor CO2 adsorption capacity, inability to efficiently generate photoexcited electrons, and/or poor transfer of the photogenerated electrons to CO2 molecules adsorbed on the catalyst surface. The integration of inorganic semiconductor nanoparticles across metal organic framework (MOF) materials has potential to yield new hybrid materials, combining the high CO2 adsorption capacity of MOF and the ability of the semiconductor nanoparticles to generate photoexcited electrons. Herein, controlled encapsulation of TiO2 and Cu–TiO2 nanoparticles within zeolitic imidazolate framework (ZIF-8) membranes was successfully accomplished, using rapid thermal deposition (RTD), and their photocatalytic efficiency toward CO2 conversion was investigated under UV irradiation. Methanol and carbon...

Membrane reactors typically combine chemically reactive pathways with separation opportunities to increase conversion and chemical processes efficiency in liquid effluents treatment. The treatment of industrial bio-products, waste mixed solvents and agro-chemicals with such reactors are however challenging due to the natural affinity of such reactive materials for organic and biological matter leading to surface adsorption and fouling tendencies. Here, hybrid thin film composite catalytic membranes offering superior flow permeation characteristics, extremely high retention of low molecular weight organics and partial salt rejection capabilities were for the first time synthesized. Catalytic silver-metal nano-materials were for the first time homogeneously templated and encapsulated across metal organic frameworks nano-particles and incorporated across the top surface of poly(amide) thin films during interfacial polymerization. These novel materials offer high catalytic/anti-microbial behaviours due to the nano-structure of the metal nano-particles reduced within the metal organic framework template, forming unique hierarchical sub-100 nm hybrid nano-structures. These ultra-thin but yet dense membranes were able to simultaneously degrade chemicals and filter contaminants, opening new pathways for the design of the next generation thin film nano-composite membranes. Catalytic properties and homogeneity were evaluated for the Fenton-like heterogeneous catalytic degradation of 2,4-Dichlorophenoxyacetic acid, a waste pesticide contained in agricultural wastewater.

Metal organic frameworks (MOFs) are hybrid crystalline materials, exhibiting high specific surface areas, controllable pore sizes and surface chemistry. These properties have made MOFs attractive for a wide range of applications including gas separation, gas storage, sensing, drug delivery and catalysis. This review focuses on recent progress in the application of MOF materials as catalysts for CO2 conversion through chemical fixation, photocatalysis and electrocatalysis. In particular, this review discusses the co-relationship between the physicochemical properties of MOF materials including their catalytic performance as well as their stability and recyclability under different reaction conditions, relevant to CO2 conversion. Current modification techniques for improving MOF performance are highlighted along with the recent understanding of their electronic properties. The limitations of MOF based catalysts are also discussed and potential routes for improvement are suggested.

Photocatalytic conversion of carbon dioxide (CO

We report the preparation of polymer capsules containing liposomal subcompartments, termed capsosomes, and their ability for the sustained delivery of protein therapeutics. Capsosomes were formed through the layer-by-layer (LbL) assembly of polymers and protein-loaded liposomes, followed by the formation of a capsule membrane based on disulfide cross-linked poly(methacrylic acid). The loading capacities of a model cargo (lysozyme) and brain-derived neurotrophic factor (BDNF), an important neurotrophin that has significant physiological functions on the nervous system, were determined, and the long-term release kinetics of the proteins was investigated in simulated physiological conditions. The capsosomes exhibited protein loading and release behavior that can be tuned by the lipid composition of the liposomal compartments, where inclusion of anionic lipids resulted in enhanced protein loading and slower release over the course of 80 days. These findings highlight the potential of capsosomes for the long-term delivery of protein therapeutics.

A facile route for synthesizing a diverse array of cargo‐loaded polymer capsules using polymer‐stabilized calcium carbonate particles is introduced by Frank Caruso and co‐workers in article number 1400007. Cargo, ranging from anti‐cancer drugs to plasmid DNA, could be loaded in high quantities, making this technique promising for a variety of applications.

The determination of pavement layer moduli from falling weight deflectometer test data is known as backcalculation analysis. Generally, backcalculation analysis is unstable–-greatly influenced by several causes of error. They may be categorized as modeling error in the forward analysis, deflection measurement error, or numerical computation error due to instability in the backcalculation procedure, for example. Because of these problems, the seed values selected for layer moduli greatly influence backcalculation results. To reduce the effects of measurement error, truncated singular-value decomposition is used for regularization. Variable scaling, often used in optimization algorithms, is implemented to improve numerical accuracy. A Ritz vector reduction method is used to solve a large system of dynamic equations in dynamic backcalculation efficiently, and various other means are introduced to decrease computational time. Recent updates of Dynamic Back Analysis for Layer Moduli software, first developed in 1993 and whose solver is based on axi-symmetric finite element method, are presented, as are examples of airfield pavement applications. Results are compared with results from Back Analysis for Layer Moduli static backcalculation software, whose solver was developed using multilayered linear elastic theory. Experience indicates that a dynamic backcalculation is superior to static back-calculation. The results from the two methods are presented and compared.

A study on how correlation among FWD deflection data influences accuracy of the backcalculated pavement layer moduli is presented. FWD data were obtained from the Ministry of Construction, Road Test Section 609 and the data with stronger correlation were used in this study. Deflections without correlation and with similar correlation to the FWD data were generated using Monte Carlo simulation in order to investigate the effect of correlation on the backcalculation results. Furthermore, backcalculation analysis using theoretical deflection data with the same standard deviation but different correlations showed smaller variation in the backcalculation results for the deflection data with stronger correlation.

Results of structural evaluation analysis of pavement using FWD data from route 219 at Saito in Miyazaki Prefecture, Japan are presented. FWD is a dynamic loading device. DSGT, a dynamic analysis method and AASHTO and NIPPO which are static analysis methods, are used for the analysis. Subgrade modulus and effective pavament full depth AC thickness are backcalculated. A potential problem of whether static analysis (mostly used method) or dynamic analysis should be performed on the data is discussed in this paper by looking at the difference of results these two methods give in the analysis of FWD data.

Polymer microcapsules are of particular interest for applications including self‐healing coatings, catalysis, bioreactions, sensing, and drug delivery. The primary way that polymer capsules can exhibit functionality relevant to these diverse fields is through the incorporation of functional cargo in the capsule cavity or wall. Diverse functional and therapeutic cargo can be loaded into polymer capsules with ease using polymer‐stabilized calcium carbonate (CaCO3) particles. A variety of examples are demonstrated, including 15 types of cargo, yielding a toolbox with effectively 500+ variations. This process uses no harsh reagents and can take less than 30 min to prepare, load, coat, and form the hollow capsules. For these reasons, it is expected that the technique will play a crucial role across scientific studies in numerous fields.

Mesoporous silica supraparticles (MS-SPs) self-assembled from mesoporous silica nanoparticles are reported on page 4244 by F. Caruso and co-workers. The MS-SPs are effective carriers for the sustained delivery of brain-derived neurotrophic factor. Animal studies show that the MS-SPs can be implanted into the cochlea and deliver neurotrophins to prevent the progressive loss of the auditory neurons that normally occurs with deafness.

This paper (Part 2 of a two-part set of papers) discusses models and illustrates the adverse effects of weak layers, interlayers, laminations and/or weak interfaces in flexible and semi-flexible pavements, also incorporating lightly cemented layers. The modelling is based on mechanistic analyses for pavement design and evaluation. In Part 1, the effects of these relatively weak layers, interlayers, laminations and/or weak interfaces were discussed. It was shown that methodologies are available to detect and investigate the existence of these weak layers in cemented pavement layers. In Part 2, several cases of the above conditions for different road pavement types are discussed, with field examples. Mechanistic analyses were done on a typical hot mix asphalt (HMA), several cases of a cemented base pavement and a granular base pavement, with and without these weak layers and interface conditions to demonstrate their adverse effects. The analyses focus on the strain energy of distortion (SED) as a pavement response parameter to indicate the potential for structural damage expected within the pavement structure or layer. Generally, the higher the SED, the higher the potential damage in the pavement layer. SED shows some potential for quantifying the relative effects of these weak layers, interlayers, laminations and/or weak interfaces within flexible and semi-flexible pavements.