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This work investigates the reactions occurring in K2CO3-H2O-CO2 under ambient CO2 pressures in temperature and vapor pressure ranges applicable for domestic thermochemical heat storage. The investigation shows that depending on reaction conditions, the primary product of a reaction is K2CO3·1.5H2O, K2CO3·2KHCO3·1.5H2O, or a mixture of both. The formation of K2CO3·1.5H2O is preferred far above the equilibrium conditions for the hydration reaction. On the other hand, the formation of double salt is preferred at conditions where hydration reaction is inhibited or impossible, as the thermogravimetric measurements identified a new phase transition line below the hydration equilibrium line. The combined X-ray diffraction, thermogravimetric analysis, and Fourier-transform infrared spectroscopy study indicates that this transition line corresponds to the formation of K2CO3·2KHCO3, which was not observed in any earlier study. In view of thermochemical heat storage, the formation of K2CO3·2KHCO3·(1.5H2O) increases the minimum charging temperature by approximately 40 °C. Nevertheless, the energy density and cyclability of the storage material can be preserved if the double salt is decomposed after each cycle.

Non-stabilized thermochemical materials impose several limitations on their use. These include swelling/shrinkage, cracking, and agglomeration over cycles. In addition, the deliquescence transition cannot be used and is even considered an unwanted side effect. In this work several salt hydrates for low temperature heat storage (K2CO3, CaCl2 and LiCl) are stabilized within a highly porous mm-sized polymer matrix. The composites containing wetting salt solutions are shown to be stable towards deliquescence. Three different composites were cycled. A K2CO3-polymer composite was cycled for 50 hydration/dehydration cycles and found to be kinetically and mechanically stable over all cycles, with swelling at higher cycle numbers. A LiCl-polymer composite was cycled for 40 cycles after which the composite became unstable. The composite containing CaCl2 was found to be kinetically and mechanically stable for 15 cycles. Composites with energy densities up to 2.4 GJ·m-3 and a peak power output of 325 W·kg-1 were fabricated which is equal or higher compared to previously reported systems. All composites have power outputs which are sustained at higher levels throughout the full discharge cycle. This work opens new pathways to stabilize salt hydrates as well-defined mm-sized particles exhibiting cyclic stability, while maintaining a high energy density and power output.

Background: Aprocitentan is an orally active, dual endothelin receptor antagonist that may offer a new therapeutic option for the treatment of difficult-to-control hypertension. Objective: To investigate safety, tolerability, mass balance, absorption, distribution, metabolism, and excretion of aprocitentan. Methods: In this single-center, open-label study, a single oral dose of 25 mg containing 3.7 MBq of 14C-radiolabeled aprocitentan was administered to 6 healthy male subjects. Metabolites were identified using mass spectrometry and, where possible, confirmed and quantified with reference compounds. Results: Aprocitentan was well tolerated and there were no clinically significant findings for any safety variable. The geometric mean cumulative recovery of radioactivity from urine and feces over 14 days was 77% of the administered radioactive dose, with 52.1% cumulative recovery from urine and 24.8% from feces. Concentrations of total radioactivity in whole blood were markedly lower compared to plasma. In plasma, 94.3% of total radioactivity was aprocitentan. In urine and feces, 5 and 2, respectively (in feces one being aprocitentan) main products were identified. Metabolism data of aprocitentan identified two main elimination pathways, glucosidation to M3 and hydrolysis to M1, representing approximately 25% and 32% of the radioactive dose, respectively. Conclusions: Based on these metabolism data, aprocitentan can be concomitantly administered without dose adjustment with drugs that are inhibitors or inducers of any metabolizing enzyme, specifically cytochrome P450 enzymes.

Potassium carbonate (K2CO3) is a promising thermochemical heat storage material (TCM). However, it suffers from hysteresis between (de)hydration temperatures and poor reaction kinetics close to equilibrium conditions. Both aspects are caused by a nucleation barrier and low ionic mobility close to equilibrium. This study investigates the impact of caesium fluoride (CsF) incorporated through recrystallisation on the phase transitions. The composition studies show that K2CO3and CsF react during synthesis, forming KF, which points to the formation of Cs2CO3. The secondary phases are not incorporated into the crystal structure but reside between the main phase's grain cracks due to capillary forces. Because the secondary phases are highly hygroscopic, they promote surface mobility by forming a liquid-like layer even at low water vapour pressures. As the effect of their presence, hydration kinetics are enhanced significantly in all investigated conditions, with the most pronounced impact when hydration of K2CO3is inherently inhibited. The benefits manifest themselves through a faster reaction rate and shorter induction period. The dehydration is enhanced by the presence of the additive mainly far away from equilibrium conditions. Close to the equilibrium, the dehydration of the composite proceeds in an unusual 2-step manner, where the second step is much slower than the dehydration of pure K2CO3. The enhancement of dehydration kinetics is ascribed to the formation of defects during recrystallisation. The lowering of dehydration rates close to equilibrium is attributed to diffusion issues due to excess of a deliquescent phase present in the system.

Cenerimod is a sphingosine-1-phosphate 1 receptor modulator under development for treatment of systemic lupus erythematosus.This single-centre, open-label, single-dose study investigated the mass b...

Thermochemical heat storage (TCHS) in salt hydrates attracts increasing interest due to the high energy density combined with loss-free storage. Strontium bromide hexahydrate (SBH), and composites thereof, are often suggested as suitable materials for this application. Although many aspects of SBH composites have been thoroughly investigated, very little has been done on the fundamental aspects of the hydration reaction and interactions between composite components on a molecular level. In this paper, we examine the interaction between SBH and polymeric additives polydiallyldimethylammonium chloride (PDAC), sodium carboxymethyl cellulose (CMC), and polyacrylic acid (PAA) in previously developed TCHS composites. The primary function of the polymeric additives is enhanced mechanical integrity however this study investigates potential implications on reaction temperature and speed the addition of such components might have. Focus is given to the interaction between SrBr2 and PDAC since such composites showed (de)hydration behaviour deviating from pure SrBr2. The reaction kinetics are investigated at several points in the phase diagram through thermogravimetric analysis (TGA), supplemented by powder x-ray diffraction (XRD) studies. Our findings show that there exists an interaction between SrBr2 and PDAC which manifests itself through shrinkage of crystallite size and increased lattice strain induced by preferential binding of PDAC to SrBr2. Depending on the PDAC content in the composite we have found out that 1) at excessive amounts PDAC inhibits hydration due to its sequestering properties 2) at low amounts it an enhances reaction kinetics due its hydrophilic nature.

Potassium carbonate is a promising salt for thermochemical heat storage. For an application mm-sized salt hydrate particles are manufactured to be loaded inside a reactor. The step towards larger particles is necessary to prevent a large pressure drop over the reactor bed during hydration/dehydration in a given air flow. Therefore, in this work a systematic study on the hydration kinetics of mm-sized disc shaped salt hydrate (K2CO3) particles is presented for the first time. The effect of density, primary particle size and driving force on the hydration kinetics was evaluated using a 1D diffusion model. The main conclusions are that the hydration kinetics of mm-sized salt hydrate particles is diffusion limited and that the particle density (porosity) and tortuosity are the main parameters controlling its performance. On the contrary, the primary powder size did not affect the particle performance in any way. It is shown that the calculated transport mechanism is unaffected by changes in driving force whereas the power output decreases with decreasing driving force. Lastly shape and size optimization is discussed which can possibly improve the hydration kinetics of salt hydrate particles in view of thermochemical heat storage. Since the particle hydration is expected to be similar for various other salts, the model from this work offers opportunities to predict and optimize particles made from different salts as well.

Potassium carbonate has recently been identified as a promising candidate for thermochemical energy storage. However, as for many salt hydrates, its reaction kinetics is relatively slow. K2CO3 has a metastable zone, where the reaction is kinetically hindered, which limits the temperature operating window. This work aims to improve the material performance, focusing on two aspects; improving the kinetics outside the metastable zone and reducing the metastable zone width. This work shows that doping with Cs2CO3, can improve both. Moreover, it is shown that the dopant enhances the hydration rate by introducing mobility due to local deliquescence. This lays the foundation for further material research using dopants to enhance the performance of salt hydrates.

This work studied the reversible dehydration of potassium carbonate sesquihydrate (K2CO3·1.5H2O). The study is based on isobaric and isothermal thermogravimetric measurements conducted at a broad range of vapour pressures and temperatures. By controlling both parameters, we examined the influence of both constraints on the reaction kinetics at a wide extent of supersaturations. We have evaluated our experimental findings by employing two thermodynamic theories, classical nucleation theory and transition state theory. By combining both approaches, we were able to establish that: (1) At low supersaturations in a region close to equilibrium, dehydration is limited by nucleation and growth of the anhydrous phase (2) At high supersaturations, dehydration reaches maximum rate and is controlled by the reaction speed. Furthermore, we show that the dehydration of K2CO3·1.5H2O is very sensitive to pressure-temperature conditions and that it does not possess universal activation energy., This publication is part of the project Mat4Heat with project number 739.017.014 of the research programme Mat4Sus which is financed by the Netherlands Research Council (NWO).

The P2Y12 receptor antagonist selatogrel which exhibits rapid inhibition of platelet aggregation following subcutaneous administration is in development for the treatment of acute myocardial infarction.This human ADME study was performed in six healthy male subjects to determine the routes of elimination and to identify/quantify the metabolites of selatogrel at a therapeutically relevant dose of 16 mg [

Stimulated by the growing demand for greener and more sustainable polymer systems we have studied thermoreversible polymer networks composed largely (> 83% w/w) of diethylitaconate of bio-based origin. A series of coating materials has been synthesized consisting of linear chains of diethylitaconate copolymerized with furfurylmethacrylate moieties enabling the formation of reversible crosslinks between the chains through the Diels-Alder reaction upon addition of a bismaleimide. The ability to reversibly crosslink these materials can be used to improve the sustainability of the coatings by elongation of the lifetime through enhancement of mechanical properties (glass transition temperature, hardness and susceptibility towards abrasive wear as well as solvent resistance have been quantified). The thermoreversibility of the network makes this kind of crosslinked coatings mendable after a damaging event during the coating life-time and ultimately recyclable. Heat induced decrosslinking of the coating materials through the retro-Diels Alder reaction has been analyzed with differential scanning calorimetry and self-healing has been demonstrated.

A literature review is performed in order to collect and analyse the thermodynamic data of an utmost number of salt hydrate reactions (i.e., 563 reactions are reviewed). These data allow us to evaluate the theoretical possibilities and limitations of salt hydrates as thermochemical materials (TCMs) for seasonal heat storage in the built environment (1 GJ/m3 on system level). Two filters are used for evaluation. Filter 1 including three criteria i.e., an ideal hydration reaction with a capacity larger than 2 GJ/m3, a hydration temperature of 65 °C (suitable for domestic hot water) or higher, a dehydration temperature below 100 °C to profit as much as possible from the solar heat that can be harvested. Only four of the studied hydrates fit with these demands. For selecting a larger number of hydrates, a second filter is introduced with less demanding constraints. It is expected that modifications on heat storage system level are needed to reach an acceptable system performance with the hydrates selected through filter 2 (hydration reaction with a capacity larger than 1.3 GJ/m3, a hydration temperature of 50 °C or higher, a dehydration temperature below 120 °C). Based on this filter, a shortlist of 25 TCM hydrate reactions are identified, including the four of filter 1. The shortlist is analyzed by considering price, chemical stability, reaction kinetics and safety for domestic environment. Based on this additional analysis with the used constraints, K2CO3 is determined to be the most promising candidate for open or closed systems, but has a low energy density. Based on the review of 563 hydrate reactions, we concluded that no ideal salt exists for seasonal heat storage under the considered boundary conditions. With the current concept of seasonal heat storage, including closed and open systems, whereby only one dehydration cycle per year is performed under a system energy density of 1 GJ/m3, it is not realistic for large scale implementation to use pure salt hydrates as heat storage material. By adjusting the constraints, such as multiple cycles per year or higher water vapor pressures, salt hydrates can still be used as TCMs. It should be mentioned that MgSO4·7H2O, MgSO4·6H2O and CaCl2·6H2O are not listed in our shortlist of 25 TCMs, although these hydrates are commonly suggested in the literature as promising TCM for seasonal heat storage. The present study on pT-characteristics shows, however, that these salts are not fitting the demands of such a heat storage system.

The advent of thermochemical energy storage (TcES), that is, storage of thermal energy by means of reversible chemical reactions, incites finding pathways of stabilization of thermochemical materials for thermal batteries of the future. Currently, salt hydrates such as LiCl·H2O, CaCl2·6H2O, and SrBr2·6H2O are being actively studied for TcES in buildings due to both high energy storage density (1-2.5 GJ/m3) and high storage duration. In this work, we report the core-shell composites "salt in hollow SiO2 spheres with mesopores"(salt = LiCl·H2O, CaCl2·6H2O, SrBr2·6H2O) for domestic TcES. The salt hydrates were encapsulated into submicrometer-sized hollow SiO2 (HS) capsules as confirmed by transmission electron microscopy (TEM) and N2 sorption analyses. High sorption/desorption rates due to mesopores of the shells were shown by thermogravimetric analysis (TGA). The sorption equilibrium for salt@HS was reported, and the applicability of the materials for domestic heat batteries was analyzed. As a result of almost the densest packing of salt@HS, the composites were shown to provide a state-of-the-art energy storage density up to 0.86 GJ/m3 on the bed level for the high-temperature lift of 32-47 °C, showing high energy storage capacity. The stability in at least 50 charging/discharging cycles was confirmed by TGA and TEM.

The solid-state hydration of salts has gained particular interest within the frame of thermochemical energy storage. In this work, the water vapor pressure-temperature (p-T) phase diagram of the following thermochemical salts was constructed by combining equilibrium and nonequilibrium hydration experiments: CuCl 2 , K 2 CO 3 , MgCl 2 ·4H 2 O, and LiCl. The hydration of CuCl 2 and K 2 CO 3 involves a metastable zone of ca. 10 K, and the induction times preceding hydration are well-described by classical homogeneous nucleation theory. It is further shown for K 2 CO 3 (metastable) and MgCl 2 ·4H 2 O (not metastable) through solubility calculations that the phase transition is not mediated by bulk dissolution. We conclude that the hydration proceeds as a solid-solid phase transition, mobilized by a wetting layer, where the mobility of the wetting layer increases with increasing vapor pressure. In view of heat storage application, the finding of metastability in thermochemical salts reveals the impact of nucleation and growth processes on the thermochemical performance and demonstrates that practical aspects like the output temperature of a thermochemical salt are defined by its metastable zone width (MZW) rather than its equilibrium phase diagram. Manipulation of the MZW by e.g. prenucleation or heterogeneous nucleation is a potential way to raise the output temperature and power on material level in thermochemical applications. © Copyright 2019 American Chemical Society.

In view of self-healing materials for high temperature applications we have studied the use of solid monomeric bismaleimide particles as embedded self-healing component dispersed in a host material. Below the self-healing activation temperature, bismaleimides remain inert while above it they may rapidly flow into cracks or damaged sections of the host matrix and subsequently heal it by polymerizing without use of an initiator. The polymerization of various maleimides is studied with NMR, ATR-IR, DSC and GPC, while the transport properties of the melt have been analyzed with rheology and capillary rise tests. Maleimide type and purity are the major factors that can be used to tune polymerization and transport properties. The system could be used to demonstrate extrinsic self-healing of a delaminated composite test-piece at 220 oC.

Six different bitumina of comparable PEN grade were investigated to gain a relation between the composition

Properties of asphalt concrete after aging are important parameters in determining the long-term performance of these materials. With the popularity of reduced temperature mixtures the question remains how this reduced temperature in short-term aging affects the long-term properties. This paper focuses on developing a robust and fundamental understanding of the effect of temperature on aging by connecting the chemistry of bitumen to its mechanics. To this end, round robin experiments are being currently conducted within 8 laboratories using four binders of the same grade 70/100 pen from different crude sources. In developing chemo-mechanical characterization techniques at the nano- and micro-scale, the material’s variability from crude-source to crude-source and its sensitivity to temperature needs to be taken into consideration. Furthermore, the development of uniform specimen preparation procedures for these bituminous materials at the nano- and micro-structural level is the focus. The chemical characterization is performed using Fourier transform infrared spectroscopy (FTIR). For the mechanical characterization rheological data is used using the dynamic shear rheometer (DSR) as well as conventional tests, e.g. needle penetration and softening point using the ring and ball method. It is shown that the short-term aging temperature affects the increase in softening point, while the consequent effect on long term aging is less pronounced.

Stimulated by the growing demand for more sustainable polymer systems, experiments were performed to develop completely recyclable epoxy‐based thermoset composite materials involving the separation, recovery, and complete reuse of both components of the composite, the resin and the fibers. In this study, a possibility to design such composites by incorporation of reversible chemistry for dedicated repair and recycling is demonstrated. Relying on Diels–Alder (DA) adducts located on the cross‐links between the polymeric chains, uncross‐linking the thermoset via the reverse DA reactions becomes possible. The network breaks up at elevated temperatures in shorter segments, which can be solubilized in solvents like acetic acid, butan‐1‐ol, or toluene. Specific processes for each of these solvents were developed to recover the resin and fibers with virtually unchanged properties. Both components were used in a second manufacturing step to produce recycled composites which display properties comparable with the original composites.

Stimulated by the growing demand for more sustainable polymers, explorative experiments were performed to substitute oil-based components by “green” monomers derived from bio-based compounds to decrease the carbon footprint of the production of such thermosets. The potential of itaconimides synthesised from itaconic anhydride e.g. obtained by fermentation of carbohydrates or by pyrolysis of citric acid and as such easily accessible from inexpensive renewable raw materials for DA based epoxy materials as well as their action to achieve retro DA switching temperatures as low as 80 °C was explored. Composites were manufactured using this new resin and mechanically tested. The thermo-reversibility of the network makes the crosslinked materials re-mendable after a damaging event and ultimately recyclable. In such a way the sustainability of the material can be improved as well as by using bio-based starting materials, by elongation of the lifetime and by complete recyclability at the end of the lifetime.

Thermochemical energy storage (TCES) is an emerging technology promising for domestic applications. Recently, K2CO3 was identified and studied as a TCES material. In this work, the composite “K2CO3 in expanded vermiculite” (69 wt. % of the salt) was prepared and studied for thermochemical energy storage bearing in mind its application for space heating. The hydration rate was found to be higher for the confined K2CO3 in comparison with K2CO3 granules of the same size. While morphology and texture of the composite alter after 74 hydration/dehydration cycles, its chemical composition and average grain size do not change. The energy storage density of the composite bed can reach 0.9 GJ/m3 (250 kWh/m3) for cycles with deliquescence which makes the composite an inexpensive thermochemical material for space heating. Stable conversion for deliquescence conditions was shown for at least 47 cycles.

Background: As part of an integrated and innovative approach to accelerate the clinical development of the dual receptor antagonist ACT-541468, 6 healthy subjects in one cohort in a first-in-humans (FIH) study received an oral dose of 50 mg non-labeled ACT-541468 together with a microtracer amount of 250 nCi of 14C-labeled ACT- 541468 to investigate its absorption, distribution, metabolism, and excretion (ADME). Methods: Using accelerator mass spectrometry (AMS), radiochromatograms were constructed for fractionated plasma, urine, and feces samples. Subsequently, the structures of the metabolites were elucidated using high performance liquid chromatography (HPLC) coupled with high resolution mass spectrometry. Results: In total 77 metabolites have been identified of which 30, 28, and 60 were present in plasma, urine, and feces, respectively. In plasma, the major metabolites were the mono-oxidized benzylic alcohol M3, the ACT-541468 aldehyde M1, formed by further oxidation of M3 in the benzylic position, and the doubly oxidized M10, formed by (1) benzylic oxidation of M3 (loss of one molecule of water and one molecule of ammonia) and (2) additional loss of water from the oxidized pyrrolidine ring of M5. Transformation of the pyrrolidine to a 6-membered ring was detected. Metabolites that accounted for more than 5% of total radioactivity in excreta were M2, which is also formed by oxidation at the benzylic position, M4, formed by demethylation of the methoxy-group, M7 and A6, both formed by oxidation of M4, and M10, the only major metabolite detected in urine. Conclusion: In conclusion, ACT-541468 is extensively metabolized predominantly by oxidative transformations.

After millions of years of evolution, nature has developed materials and systems based on the concept of damage management (healing) to extend survival possibilities. In the last 20 years, the dream of implementing this concept to engineering systems to extend service lifetime has become a reality. The field of self-healing engineering materials is growing exponentially, both in the number of research groups involved as well as the number of concepts explored, although finding applications for many of these new concepts is not straightforward. In this chapter, we focus on analyzing the main mechanisms and concepts developed in the field of self-healing polymers and introduce some explored applications of healable polymers, all from the point of view of understanding the concept of healing as the restoration of lost functionalities.

Epoxy resins are functionalized with Diels-Alder based thermo-reversible crosslinks to enable the fabrication of composites that are capable of multiple self-healing-repair processes. The key challenge in realizing a structural combination of conventional epoxy amine systems with furfuryl and maleimide functional groups is to achieve a high conversion in the reversible cross-linked polymer network formation while avoiding the major side-reactions. We have developed a two-step process consisting of a bulk prepolymerization reaction followed by a network formation step. The second step is performed in an extruder to realize a good mixing at high temperatures, while keeping the residence time at that temperature short to avoid maleimide side-reactions. The obtained oligomers are characterized using NIR, NMR, DSC, GPC analyses while solvent exposure tests and rheological measurements are performed to prove the formation of a thermo-reversible network and study their behavior in relation to the cross-linker concentration. Densely cross-linked, solvent resistant polymeric networks are obtained that maintain the ability to un-crosslink and thus regaining fluid behavior at elevated temperatures for at least five subsequent heat cycles. Glass fiber reinforced polymer composite films, which are fabricated using these resins, demonstrate that the thermo-reversible effect is strong enough to achieve full self-healing of a severely cracked and delaminated test specimen.

Six MgAl hydrotalcites (Mg/Al = 2 and 3) were synthesized through the modification of two carbonate hydrotalcites (i.e., Mg(2)AlCO3 and Mg(3)AlCO3) by two amino acids (11aminoundecanoic acid and paminobenzoic acid) and sodium nitrite. They were characterized by means of XRD, FTIR, TG/DSC, and elemental analysis. The ion exchange of the modified hydrotalcites (MHTs) were investigated in alkaline chloride solution and the results showed that ion exchange occurred between free chloride ions and the intercalated inhibitive anions in MHT. The corrosion inhibition of three MHTs (Mg/Al = 2) was evaluated based on the open circuit potential and linear polarization resistance evolution of steel coupons in 0.1 M NaOH solution stepwise enriched with chlorides and the results showed that MHT, in particular, Mg(2)AlpAB exhibited an improved corrosion inhibiting effect in terms of a higher chloride threshold compared to its constituent free inhibitor ions (i.e., pAB). This study confirms the dual protection that MHT, in particular, Mg(2)AlpAB, offers to the steel: capturing chlorides and simultaneously releasing the intercalated inhibitors to further protect the steel from corrosion.

Bitumen and bituminous binders are a mixture of a wide variety of molecules with different size and nature; a-polar as well as polar, aromatic as well as aliphatic, chain-like as well as two-dimensional in nature. However, most of the bitumina display at ambient temperatures a spontaneous formation of micro-phases displaying different mechanical properties such as stiffness or adhesive behaviour. The actual chemical composition of the individual phases is still a matter/subject of discussion. The application of different scanning probe microscopy modes such as FFM, SThM and SNOM enabled the investigation of the relationships between asphalt microstructure and material characteristics such as friction coefficient, thermal conductivity and chemical composition and polarity. It was possible to collect data providing more and detailed information's on a nano-scale and in detail with respect to the different micro-phases present in bituminous binders. All data collected fit into the present picture of structuring of bitumen and the characteristics of the present phases.

Owing to the unique molecular structure and high ion exchange capacity, hydrotalcites are believed to have a potential to be modified and tailor-made as an active component of mortar and/or concrete. In this paper, two types of modified hydrotalcites (MHT-pAB and MHT-NO2) were incorporated into cement mortars with two dosage levels replacing 5% and 10% weight of cement. Designated testing programme including workability test, strength test, porosity test, and rapid chloride migration and diffusion test were employed to investigate the effect of the two modified hydrotalcites on chloride penetration in cement mortar. The results based on these tests indicated that the incorporation of MHT-pAB at 5% dosage in mortar produced a notably improved chloride diffusion resistance with no remarkably negative influence on the development of mechanical strength and the workability of fresh mortar, which therefore validated that the MHT-pAB could be a promising alternative in hindering the chloride transport in mortar when an appropriate mixing dosage is adopted. © 2015 Elsevier Ltd All rights reserved.

Thermochemical materials K2CO3, MgCl2 and Na2S have been investigated in depth on energy density, power output and chemical stability in view of domestic heat storage application, presenting a critical assessment of potential chemical side reactions in an open and closed reactor concept. These materials were selected based on a recent review on all possible salt hydrates, within the frame of a thermochemical heat battery and considering recent advances in heat storage application. Judged by gravimetric and calorimetric experiments in operating conditions and worst-case-scenario conditions, K2CO3 is recommended for both an open and closed system heat battery. The compound is chemically robust with a material level energy density of 1.28 GJ/m3 in an open system and 0.95 GJ/m3 in a closed system, yielding a power output of 283–675 kW/m3. Na2S and MgCl2 on the other hand are chemically not robust in heat storage application, although having a higher energy density, output power and temperature in one cycle.

A direct bonding process relying on van der Waals forces offers an ideal combination of easiness to assemble and material compatibility. Such a bonding procedure, also denoted as optical bonding, is already known and used frequently in different applications. However, there are strict requirements to achieve optical bonding: (1) a high level of cleanliness of the surfaces and (2) low roughness (RMS roughness

A combined experimental and numerical investigation is conducted on the anisotropic water diffusion behaviour of unidirectional glass/epoxy composites. Experimental diffusivity values are obtained by immersing thin material slices for each of its planes of orthotropy extracted from a thick composite panel and interphase measurements are performed using thermal analysis. In order to elucidate the observed anisotropy, the diffusion process is modelled at the microscale using a representative volume element (RVE) of the material with random fibre distribution. Water concentration gradients are applied to the micromodel and a homogenisation procedure is used to retrieve the macroscopic diffusivity coefficients. The influence of the interphase around the fibres on the diffusion process is modelled by making the matrix diffusivity a function of the distance to the nearest fibre using a level set field. The models are used to fit the experimental data and test a number of hypotheses that may explain the observed anisotropy. The effect of fibres acting as barriers for water movement is found to partially explain the observed transverse diffusivity. However, a fit is only obtained by allowing faster diffusivity at the interphase. In the longitudinal direction, a fit can only be found by allowing for orthotropic interphase diffusivity.

The occurrence of discrete cracking of bitumen and asphalt is difficult to observe/analyse mainly because of the viscous nature of the bitumen binder. Many techniques simply do not have the required resolution or analysis techniques do not get a good response from the highly dissipative bitumen. In this study, an attempt is made to visualise failure development under straining conditions in bitumen with the use of an in situ tensile tester combined with atomic force microscopy. From the experiments, it was observed that cracks or strain localisations occur in the perpetua phase though only significantly for aged binder (i.e. more than six months at room temperature). Furthermore, the locations of these cracks or strain localisations occur on the edges of the more rigid peri phase and were oriented in the direction of tension. This is a clear indication that the bitumen's microstructure does affect homogeneity of the internal stress and strain fields and effectively causes non-homogeneous straining and even localisation in regions where stress concentrations are present. Furthermore, the recovery of the strain localised zones was studied. The strain localised zones completely recovered in the course of several hours.

Two modified hydrotalcites (MHTs) intercalated with nitrate and aminobenzonate anions, (i.e., CaAl-MHT-NO3 and CaAl-MHT-pAB) have been synthesized. The intercalation of CaAl-MHT-pAB was achieved by anion exchange of nitrate in the host material, CaAl-MHT-NO3, which was prepared by a coprecipitation method. Materials characterization was conducted by means of X-ray diffraction (XRD), thermal analysis, IR-spectroscopy and environmental scanning electron microscope (ESEM). Element analysis further confirmed both nitrate and p-aminobenzonate anions were successfully intercalated into the interlayer space of MHTs with an intercalating ratio of 81.2% and 33.1% respectively. Volhard’s titrimetric analysis demonstrated that ion exchange occurred between free chlorides in simulated concrete pore solution and anions intercalated in MHTs. The preliminary results reported in this paper shed light on the promising use of MHTs as a new type of additive for improved corrosion protection of reinforced concrete.

Bitumen, the residue of oil distillation and applied e.g. as binder in asphalt pavements displays a rich microstructure at the bitumen surface-to-air surface with several clearly distinguishable phases. However, uncertainty still remains whether this micro-structure is just present at free surfaces or a similar structure exists in the bulk of the material. Two new experimental techniques in bitumen research (i) one based on Atomic Force Microscopy (AFM) on a freeze-fracture surface and (ii) one technique employing a Scanning Acoustic Microscope (SAM) offer the required spatial resolution and show the presence of two phases in the bulk showing similarities with the known surface structures in bitumen. © 2013 Elsevier Ltd. All rights reserved.

A carbonate form of MgAl hydrotalcite, Mg(2)Al-CO3 and its p-aminobenzoate (pAB) modified derivative, Mg(2)Al-pAB, were synthesized and characterized by means of XRD, FT-IR and TG/DSC. The anticorrosion behavior of Mg(2)Al-pAB was evaluated based on open circuit potential (OCP) of carbon steel in simulated concrete pore solution and on chloride-exchange experiments. The results reported in this paper demonstrate that ion-exchange indeed occurred between chlorides and intercalated pAB anions, thereby reducing the free chloride concentration in simulated concrete pore solution. The simultaneously released pAB anions were found to exhibit the envisioned inhibiting effect and caused corrosion initiation of the steel to shift to higher chloride concentrations than without the modified hydrotalcites. © 2013 Elsevier Ltd. All rights reserved.

The objective of this work is to study the common features and the evolution of microstructures of bituminous binders regardless of their grade (PEN 10/20 to 160/220) and source/origin using the atomic force microscope operated in phase contrast mode. All bituminous binders show the same microstructural features, consisting of three distinct phases, the perpetua-, peri- and catana-phase. The perpetua-phase is soft and viscoelastic in nature, the peri-phase is relatively stiff and solid in nature and the catana-phase is alternatingly hard and soft in nature and is always found in the middle of the peri-phase. Experiments at different temperatures result in a quantitative picture of the changes/transitions between the different microphases upon heating. Phase formation is reversible with respect to temperature, upon heating homogenisation occurs and upon cooling re-formation of the phases can be observed. © 2013 © 2013 Taylor & Francis.

Nylon 6 films are directly exposed to saline solutions containing mono-valent ions and the water uptake is measured with magnetic resonance imaging (MRI). Both the amount of water uptake and the rate of water uptake are studied. First, the films are exposed to solutions with different concentrations of NaCl. Later, solutions of salts such as LiCl, KCl and KNO3 are used. It is shown that all salts act similar. They reduce the amount of water ingressing the nylon film and also slow down the rate of uptake. It seems that water uptake can be predicted by knowing the activity of the salt solution on top of the nylon film. Element analysis shows that ions migrate into the nylon film. Although ions do enter the film, their amount is not large enough to influence the diffusivity and chemical potential of water in the nylon film.

The mechanical properties of bitumen, such as elasticity/Young's modulus, stickiness/adhesion, hardness and energy loss, and sample deformation were acquired quantitatively and simultaneously with the topology at the microscale, discriminating clearly two separate phases within the bitumen. Temperature-dependent measurements revealed detailed and specific data about the changes of these properties with temperature, enabling the development of predictive models for the performance and durability of asphalt. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

A facile two-step process is developed to obtain polyester urethanes that contain various concentrations of thermoreversible Diels–Alder adduct–based bonds for the development of adhesives. Besides linear systems thermoreversible networks have been included in the study. The reactions are verified using IR-spectroscopy and gel permeation chromatography analysis. The material properties are characterized with solvent exposure tests, dynamic scanning calorimetry, microindentation and rheology and the potential for application as adhesives is tested with an elcometer. Material properties have been found highly tunable for the system, and high adhesive strengths (off-scale) are found for polyester urethanes that are doped with an intermediate level Diels–Alder functional groups. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44972.