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This paper aims to evaluate the reduction in greenhouse gas emissions of rice and wheat and their supply chains by incorporating carbon capture, utilisation and storage into fertiliser production mainly from the ammonia process, which is a part of the fertiliser that produces most of the carbon dioxide. Greenhouse gas emissions of these grains without carbon capture, utilisation and storage are provided from the results of life cycle assessment in the literature. After that, carbon dioxide emission from fertiliser production is quantified. The alternative considered for utilisation is enhanced oil recovery and it is compared with the conventional way of oil production. The effects of carbon capture, utilisation, and storage on greenhouse gas reduction are presented in terms of the supply chains of rice and wheat to make people conscious about the use and optimisation of food. The reduction of greenhouse gas is around 6–7% in the rice supply chain e.g. rice milk, spoons of uncooked rice and 14–16% in the wheat supply chain e.g. pasta, one slice of bread. Although the alternative for carbon dioxide storage demonstrates marginally higher greenhouse gas reduction, enhanced oil recovery may offer an economic incentive from additional oil production that could reduce the cost of rice and wheat.

The process of stabilization is essential in the production of carbon fibers from lignins. During stabilization, the initially thermoplastic lignin polymer is converted to a thermoset polymer allowing for high-temperature treatment without a change in shape. In this work, hardwood (HKL) and softwood (SKL) Kraft lignins were stabilized in air at temperatures between 190 and 340 °C before carbonization at 800 °C in a nitrogen atmosphere. Due to the differences in side-chain linkages, functional groups and molar mass, the lignins exhibit different structural changes upon stabilization and hence develop different porosities upon carbonization. Both lignins undergo major crosslinking reactions in the side chains at low temperatures and degradation reactions at high temperatures during stabilization. Crosslinking gives rise to narrow pore size distributions with mainly (sub-) nanometer pores, whereas degradation reactions lead to a more open pore structure with additional mesoporosity (>2 nm). When both types of reactions take place simultaneously, highly accessible (sub-) nanoporosity can be effectively created, which boosts the performance of supercapacitors operating in 6 M KOH(aq). This effect terminates when the crosslinking reactions cease and mainly degradation reactions take place, which occurs in HKL at 340 °C. SKL shows both a lower degree of crosslinking and degradation and hence develops less specific surface area. The optimum performance in an aqueous alkaline supercapacitor is achieved with HKL stabilized at 310 °C. It shows a specific gravimetric capacitance of 164 F g−1 at 0.1 A g−1 and 119 F g−1 at 250 A g−1 with a capacitance retention of more than 90% after 10 000 cycles. M. J. M. L. and D. C. A. thank Spanish Ministry of Science, Innovation and Universities and FEDER (project RTI2018-095291-B-I00) for financial support. C. P. G. and C. O'K. thank Shell. MMT and PS thank RISE AB for co-funding Philipp Schlee's PhD position.

Softwood is an abundantly available feedstock for the bio-based industry. However, achieving cost-effective sugar release is particularly challenging, owing to its guaiacyl-only lignin. Here, we report the highly effective pretreatment of the softwood pine (Pinus sylvestris) using ionoSolv pretreatment, a novel ionic liquid-based lignocellulose fractionation technology. Three protic, low-cost ionic liquids, 1-butylimidazolium hydrogen sulfate, triethylammonium hydrogen sulfate and N,N-dimethylbutylammonium hydrogen sulfate, were used to fractionate the biomass into a carbohydrate-rich pulp and a lignin. The carbohydrate-rich pulp was hydrolysed into fermentable sugars by enzymatic saccharification. Under the most successful pretreatment conditions, quantitative glucose release from the pulp was achieved, which equates to a projected glucose release of 464 mg per gram of pine wood entering the process. We further intensified the process by increasing the solid to solvent ratio up to 1 : 2 g g−1 while maintaining saccharification yields of 75% of the theoretical maximum. We also demonstrate for the first time that N,N-dimethylbutylammonium hydrogen sulfate, [DMBA][HSO4], is an excellent low-cost pretreatment solvent, surpassing the pretreatment effectiveness of its symmetrically substituted analogue triethylammonium hydrogen sulfate. This shows that ionoSolv pretreatment with protic hydrogen sulfate ionic liquids is a truly feedstock-independent pretreatment option, further increasing the commercial potential of this pretreatment technology.

This paper describes the development of a test kit for the selective detection of glyphosate (GlyP). A copper(ii)-pyrocatechol violet complex was selected by a screening approach from a pool of 96 combinations of metal ions and commercially available indicators and subsequently incorporated as a detection zone into a hydrophobic C18 solid support. With this kit, detection of 20 μM GlyP in tap water by the “naked eye” is possible and quantifications by smartphone analysis with a limit of detection as low as 2.66 μM (450 μg L−1) have been demonstrated in a proof-of-principle study., This paper describes the development of a test kit for the naked-eye detection of glyphosate (GlyP) using a copper(ii)-pyrocatechol violet complex immobilized on a C18 solid support.

11 pags., 5 figs., 3 tabs. -- We adknowledge support by the CSIC Open Access Publication Initiative through its Unit Information Resources for Research (URICI). -- Open Access funded by Creative Commons Atribution Licence 3.0, Absolute total electron scattering cross sections (TCS) for nitrobenzene molecules with impact energies from 0.4 to 1000 eV have been measured by means of two different electron-transmission experimental arrangements. For the lower energies (0.4–250 eV) a magnetically confined electron beam system has been used, while for energies above 100 eV a linear beam transmission technique with high angular resolution allowed accurate measurements up to 1000 eV impact energy. In both cases random uncertainties were maintained below 5–8%. Systematic errors arising from the angular and energy resolution limits of each apparatus are analysed in detail and quantified with the help of our theoretical calculations. Differential elastic and integral elastic, excitation and ionisation as well as momentum transfer cross sections have been calculated, for the whole energy range considered here, by using an independent atom model in combination with the screening corrected additivity rule method including interference effects (IAM-SCARI). Due to the significant permanent dipole moment of nitrobenzene, additional differential and integral rotational excitation cross sections have been calculated in the framework of the Born approximation. If we ignore the rotational excitations, our calculated total cross section agrees well with our experimental results for impact energies above 15 eV. Additionally, they overlap at 10 eV with the low energy Schwinger Multichannel method with Pseudo Potentials (SMCPP) calculation available in the literature (L. S. Maioli and M. H. F. Bettega, J. Chem. Phys., 2017, 147, 164305). We find a broad feature in the experimental TCS at around 1.0 eV, which has been related to the formation of the NO2 anion and assigned to the p*(b1) resonance, according to previous mass spectra available in the literature. Other local maxima in the TCSs are found at 4.0 0.2 and 5.0 0.2 eV and are assigned to core excited resonances leading to the formation of the NO2 and O2 anions, respectively. Finally, for energies below 10 eV, differences found between the present measurements, the SMCPP calculation and our previous data for non-polar benzene have revealed the importance of accurately calculating the rotational excitation contribution to the TCS before comparing theoretical and experimental data. This comparison suggests that our dipole-Born calculation for nitrobenzene overestimates the magnitude of the rotational excitation cross sections below 10 eV., This study has partially been supported by the Spanish Ministerio de Ciencia, Innovacion y Universidades (Project FIS2016-80440) and CSIC (Project LINKA 20085). F. C. acknowledges Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, PD/00193/2012); UCIBIO (UIDB/04378/2020) and together with P. L. V. the Portuguese National Funding Agency FCT through the Research Grants CEFITEC (UIDB/00068/2020) and PTDC/FISAQM/31281/2017. M. J. B. thanks the Australian Research Council for funding through grants DP160102787 and DP180101655. The authors acknowledge Dr N. C. Jones for providing her full experimental TCS data on NBz molecules and Dr L. S. Maioli and Prof. M. H. F. Bettega for providing numerical tables of their SMCPP calculation and taking part in helpful discussions related to this paper. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). Finally we also acknowledge Dr L. Campbell for his contributions to the final version of this paper.

This paper reports that various thermodynamic properties in aqueous media for certain individual ions and for compounds are linear functions of the inverse cube root of the solid respective ionic and compound solid state volumes, V m –1/3 . This is similar to the situation which has been fully exploited in solid state thermodynamics and out of which Volume–Based Thermodynamics, VBT evolved. A short resume of these various VBT applications is provided for the general reader and an improved lattice potential energy equation emerges using the state of the art data presented in this paper.

The ability to easily and reliably predict quantum interference (QI) behaviour would facilitate the design of functional molecular wires with potential applications in switches, transistors and thermoelectric devices. A variety of predictive methods exist, but with the exception of computationally-expensive DFT-based charge transport simulations, these often fail to account for the experimentally observed behaviour of molecules that differ significantly in structure from alternant polycyclic aromatic hydrocarbons. By considering a range of prior studies we have developed an extension to predictive “curly arrow rules”. We show that, in most cases, these extended curly arrow rules (ECARs) can rationalise the type of QI exhibited by conjugated molecular wires containing heteroatoms, cross-conjugation and/or non-alternant structures. ECARs provide a straightforward “pen-and-paper” method to predict whether a molecular wire will display constructive, destructive or “shifted destructive” QI,i.e.whether or not its transmission function would be expected to show an antiresonance, and if this antiresonance would occur close to the Fermi energy or be shifted elsewhere.

This paper investigates the control of effective magnetic anisotropy in Permalloy linear chain arrays, achieved by tuning the symmetry arrangement of the ellipsoidal nanomagnets and the film thickness. When the ellipsoidal nanomagnets are coupled along their easy axis, stronger effective magnetic anisotropy is achieved compared to when the nanomagnets are coupled along their hard axis. A clear transition from a single domain state to a combination of complex flux closure states such as a vortex or double vortices is observed at different applied field angles when the film thickness is varied in the range from 20 nm to 100 nm. Tunable microwave absorption spectra, obtained by ferromagnetic resonance spectroscopy, established the complex interplay between the shape anisotropy and magnetostatic interactions, which becomes more intriguing at different film thicknesses and applied field angles. The micromagnetic simulations are in good agreement with the experimental results. Our results demonstrate possible ways of manipulating the effective magnetic anisotropy in arrays of nanomagnets for magnonic and microwave applications.

This paper follows on from the Concluding Remarks presentation of the 3rd Faraday Discussion Meeting on Artificial Photosynthesis, Cambridge, UK, 25-27th March 2019. It aims to discuss the context for the research discussed at this meeting, starting with an overview of the motivation for research on artificial photosynthesis. It then goes onto analysing the composition and trends in the field of artificial photosynthesis, and its scale relative to other related research areas, primarily using the results of searches of publication data bases. As such, we hope it provides helpful insights to researchers in the field.

Made available in DSpace on 2019-10-06T17:12:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 The development of supported catalysts based on simple procedures without waste products and time-consuming steps is highly desirable. In this paper, self-supported nickel-based nanoparticles were obtained at the surface of the germanophosphate glasses by bottom-up process and evaluated as potential catalysts for the benzyl alcohol oxidation and bis(indolyl)methanes synthesis. A classical melt-quenching technique was used for preparing the nickel-doped germanophosphate glasses, followed by annealing under a hydrogen atmosphere at 400 °C for two different times. The approach enabled the synthesis of self-supported nanoparticles as a homogeneous film, covering the glass surface. The physical and chemical properties of synthesized glasses were characterized by UV-vis and Raman spectroscopies and thermal analysis. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were performed to monitor the growth process, morphology and chemical bonding structure of the nanoparticles surface. Universidade Federal Do Paraná - UFPR Departamento de Engenharias e Exatas Universidade Tecnológica Federal Paraná - UTFPR Group of Polymers and Nanostructures Universidade Federal de São Carlos Departamento de Química Universidade de Brasília - UNB Instituto de Química Universidade Do Estado de São Paulo - UNESP Instituto de Química Universidade Estadual Do Oeste Do Paraná - UNIOESTE Departamento de Química Universidade de Brasília - UNB Instituto de Física Núcleo de Física Aplicada Universidade Do Estado de São Paulo - UNESP Instituto de Química

Due to the importance of the Gibbs free energy of solvation in understanding many physicochemical phenomena, including lipophilicity, phase equilibria and liquid-phase reaction equilibrium and kinetics, there is a need for predictive models that can be applied across large sets of solvents and solutes. In this paper, we propose two quantitative structure property relationships (QSPRs) to predict the Gibbs free energy of solvation, developed using partial least squares (PLS) and multivariate linear regression (MLR) methods for 295 solutes in 210 solvents with total number of data points of 1777. Unlike other QSPR models, the proposed models are not restricted to a specific solvent or solute. Furthermore, while most QSPR models include either experimental or quantum mechanical descriptors, the proposed models combine both, using experimental descriptors to represent the solvent and quantum mechanical descriptors to represent the solute. Up to twelve experimental descriptors and nine quantum mechanical descriptors are considered in the proposed models. Extensive internal and external validation is undertaken to assess model accuracy in predicting the Gibbs free energy of solvation for a large number of solute/solvent pairs. The best MLR model, which includes three solute descriptors and two solvent properties, yields a coefficient of determination (R2) of 0.88 and a root mean squared error (RMSE) of 0.59 kcal mol-1 for the training set. The best PLS model includes six latent variables, and has an R2 value of 0.91 and a RMSE of 0.52 kcal mol-1. The proposed models are compared to selected results based on continuum solvation quantum chemistry calculations. They enable the fast prediction of the Gibbs free energy of solvation of a wide range of solutes in different solvents.

In a seminal work the photodissociation of IBr has been controlled using a strong non-resonant IR pulse [Sussman et al., Science, 2006, 314, 274], changing the branching ratio of products in different final states via the relative timing of pump and control pulses. In this paper, we revisit the control of this molecule. Potential surfaces for the complete spin-orbit manifold of IBr states dissociating into the ground and first excited states of the constituent atoms have been calculated at the multi-reference configuration interaction (MRCI) level of theory as a function of applied field. Both the strength and direction of field have been taken into account and it is seen how the avoided crossing between the states thought to be key in the control mechanism shift as a function of field strength. These surfaces will enable full calculations of the molecule in the pump-control field. Preliminary dynamics calculations with the field placed along the molecular axis show that a Hamiltonian including all 36-states agrees with earlier results and is able to model the basic features of the control. However, just like earlier results, this restricted model is not able to reproduce the timescale of the control.

In this paper we report the synthesis and characterization of hybrid molecular-inorganic systems composed of superparamagnetic iron oxide nanoparticles coated with a shell of oleic acid (NP) and (Pr2NH2)5[Dy12(OH)16(SALO)4(SALOH)8(NO3)8(H2O)0.5]NO3 (Dy12) single-molecule magnets. The hybrid NP-Dy12 system presents an enhancement of the magnetization hysteresis with respect to the isolated components while retaining the morphological characteristics of the parent NPs.

Self-assembled cationic micelles are an attractive platform for binding biologically-relevant polyanions such as heparin. This has potential applications in coagulation control, where a synthetic heparin rescue agent could be a useful replacement for protamine, which is in current clinical use. However, micelles can have low stability in human serum and unacceptable toxicity profiles. This paper reports the optimi- sation of self-assembled multivalent (SAMul) arrays of amphiphilic ligands to bind heparin in competitive conditions. Specifically, modification of the hydrophobic unit kinetically stabilises the self-assembled nanostructures, preventing loss of binding ability in the presence of human serum – cholesterol hydro- phobic units significantly outperform systems with a simple aliphatic chain. It is demonstrated that serum albumin disrupts the binding thermodynamics of the latter system. Molecular simulation shows aliphatic lipids can more easily be removed from the self-assembled nanostructures than the cholesterol ana- logues. This agrees with the experimental observation that the cholesterol-based systems undergo slower disassembly and subsequent degradation via ester hydrolysis. Furthermore, by stabilising the SAMul nano- structures, toxicity towards human cells is decreased and biocompatibility enhanced, with markedly improved survival of human hepatoblastoma cells in an MTT assay.

Air gasification of poultry litter was experimentally investigated in a laboratory scale bubbling fluidised bed gasifier. Gasification tests were conducted at atmospheric pressure using silica sand as the bed material. This paper examines the effect of the equivalence ratio (ER) in the range of 0.18-0.41, temperature between 700 and 800 °C, and the addition of limestone blended with the poultry litter on the yield and composition of tar. An off-line solid phase adsorption method was employed in order to quantify tar compounds heavier than styrene, whereas lighter species such as benzene and toluene were measured by means of on-line micro gas chromatography. Total tar yields were in the range from 15.7 to 30.7 g total tar kg poultry litter (dry and ash free basis) -1 . These values are considered low with respect to the feedstocks with a higher organic fraction. It also needs to be noted that the yields of benzene and toluene were measured by on-line micro gas chromatography, a technique which inherently delivers higher tar values compared to commonly employed off-line techniques. By varying the ER, poultry litter blended with limestone showed a reduction in total tar yield whereas poultry litter on its own showed an increasing tar yield over the ER range tested. In the presence of limestone, polycyclic aromatic hydrocarbons (PAHs), heterocyclic compounds, toluene and benzene showed a tendency to reduce over the ER range tested. Since the ER also plays a crucial role in tar reduction, the reduction in tar cannot be unambiguously attributed to calcined limestone/lime (CaCO 3 /CaO). Increasing the temperature was shown to be effective for reducing the total tar yield but the amounts of polycyclic aromatic hydrocarbons increased. However, no definitive correlation could be established between limestone/lime catalytic activity for tar reduction and elevated gasification temperature, because there was no possibility to study their effects separately. The chemical composition of the tar arising from poultry litter is distinctive compared with conventional lignocellulosic fuels linked to the fact that poultry litter has a higher nitrogen content (≈6.5% w/w (dry and ash free basis)). Nitrogen-containing hydrocarbons such as pyridine, 2-methylpyridine, 2-methyl-1H-pyrrole and benzonitrile were identified in significant amounts. This study has demonstrated that poultry litter gasified in a bubbling fluidised bed yielded a product gas with relatively low tar content while its composition reflects the chemical nature of the feedstock. European Union FP7/2007-201 289887 INTERREG IVB NEW REsource Innovation Network 317J-RENEW Spanish Ministry of Economy and Competitiveness CTM2016-78089-R, AEI/FEDER, UE

The use of coarse-grained models is important in many fields, especially those that use computer simulation to analyze large systems in processes that span long-time scales, as happens in protein folding. Among those approaches, structure-based models have been widely and successfully used for a few decades now. They usually take a single native conformation, experimentally solved, of the protein studied to determine the native contacts, which subsequently define the interaction potential for the simulation. The characteristics of the folding transition can then be analyzed from the computed trajectories. In this paper, we consider the possibility of enriching these models by considering the structural fluctuations present in the native state of a globular protein at room temperature in an aqueous environment. We use the different conformers experimentally provided when the protein structure was determined by nuclear magnetic resonance (NMR) spectroscopy as an approximate ensemble to test our methodology, which includes the definition of a global interaction potential and the analysis of the thermodynamic and structural characteristics of the folding process. The results are compared with traditional, single structure models.

We demonstrate a rapid, 2-step, and ultrasensitive assay approach for quantification of target protein molecules from a single droplet test sample. The assay is comprised of antibody-conjugated gold nanoparticles (AuNPs) that are “activated” when they are mixed with the test sample and bind their targets. The resulting liquid is passed through a microfluidic channel with a photonic crystal (PC) biosensor that is functionalized with secondary antibodies to the target biomarker, so that only activated AuNPs are captured. Utilizing recently demonstrated hybrid optical coupling between the plasmon resonance of the AuNP and the resonance of the PC, each captured AuNP efficiently quenches the resonant reflection of the PC, thus enabling the captured AuNPs to be digitally counted with high signal-to-noise. To achieve a 2-step assay process that is performed on a single droplet test sample without washing steps or active pump elements, controlled single-pass flow rate is obtained with an absorbing paper pad waste reservoir embedded in a microfluidic cartridge. We use the activate capture and digital counting (AC + DC) approach to demonstrate HIV-1 capsid antigen p24 detection from a 40 μL spiked-in human serum sample at a one thousand-fold dynamic range (1–103 pg mL−1) with only a 35-minute process that is compatible with point-of-care (POC) analysis. The AC + DC approach allows for ultrasensitive and ultrafast biomolecule detection, with potential applications in infectious disease diagnostics and early stage disease monitoring. This work is supported by the National Institutes of Health (NIH) R01 AI20683, F30AI122925, and the Carl Woese Institute for Genomic Biology postdoctoral fellowship.

In the present paper we report experimental and theoretical evidence for lithium biphenyl disproportionation in solution. The presence of an absorption band (at 250 nm), which corresponds to neutral biphenyl in the spectra of dissolved crystalline [Li+(THP)4][Bph˙−] (1), clearly suggests the disproportionation of the biphenyl radical anion into neutral biphenyl plus the corresponding dianion, 2Bph˙− ⇄ Bph2− + Bph0. The experimental spectrum of 1 displays four main groups of bands at 834, 644, 408 and 250 nm. Upon addition of an excess of lithium, the biphenyl band becomes diminished revealing a hidden lower intensity band at 262 nm, this one truly belonging to the dianion. Highly accurate time-dependent density functional theory (TDDFT) calculations of the electronic spectra of a series of contact as well as solvent separated ionic associate models, performed at the wB97XD/6-311++G(3df,3pd) level of theory in dimethoxyethane (DME) solution, revealed that the contact lithium biphenyl dianion [(Li+DME)2Bph2−] predicts all the main absorption bands fairly well, while the corresponding radical anion does not reproduce the experimental spectral pattern. Analysis of the electron density distribution performed by means of Quantum Theory of Atoms in Molecules (QTAIM) confirms that the studied ionic associates represent the correct resonance structures since the charges of the lithium cations are close to +1 in all the cases. Solvation usually plays a key role in these types of equilibria; however the underlying cause of this disproportionation seems to lie on the inherent electronic stabilities of the anionic species involved, as could be inferred from the reported free energy calculations of the nude ion associates, neglecting any solvent effects. Financial support by the Spanish Ministry of Economy and Competitiveness (Grant No. MAT2016-78625-C2-2-P), the Ministry of Education and Science of Ukraine, Research Fund (Grant No. 0117U003908), the Generalitat Valenciana (Grant PROMETEO/2017/139) and the University of Alicante (VIGROB-285) is gratefully acknowledged. MC thanks the VIDI of the University of Alicante for a predoctoral grant.

This paper addresses the synthesis and a detailed electrical analysis of individual copper nanowires (CuNWs). One dimensional CuNWs are chemically grown using Bromide ions (Br-) as a co-capping agent. By partially replacing alkyl amines with Br-, the isotropic growth on Cu seeds was suppressed during the synthesis. To study the electrical properties of individual CuNWs, a fabrication method is developed which does not require any e-beam lithography process. Chemically grown CuNWs have an ampacity of about 30 million amps per cm2, which is more than one order of magnitude larger than the bulk Cu. These good qualities easy to synthesize CuNWs are an excellent candidate for creating high ampacity wires and flexible printable electronics.

NOTICE: This is the peer reviewed version of the following article: Fuertes A, Juanes M, Granja J, Montenegro J. Supramolecular functional assemblies: dynamic membrane transporters and peptide nanotubular composites. Chem Commun. 2017;53(56):7861-7871. [doi: 10.1039/C7CC02997G]. This article may be used for non-commercial purposes in accordance with RSC Terms and Conditions for self-archiving The fabrication of functional molecular devices constitutes one of the most important current challenges for chemical sciences. The complex processes accomplished by living systems continuously demand the assistance of non-covalent interactions between molecular building blocks. Additionally, these building blocks (proteins, membranes, nucleotides) are also constituted by self-assembled structures. Therefore, supramolecular chemistry is the discipline required to understand the properties of the minimal self-assembled building blocks of living systems and to develop new functional smart materials. In the first part of this feature article, we highlight selected examples of the preparation of supramolecular membrane transporters with special emphasis in the application of dynamic covalent bonds. In the second section of the paper we review recent breakthroughs in the preparation of peptide nanotubes hybrids with functional applications. The development of these devices constitutes an exciting process from where we can learn how to understand and manipulate supramolecular functional assemblies We acknowledge funding from the Spanish Agencia Estatal de Investigación (AEI) (CTQ2014-59646-R and CTQ2016-78423-R), the Xunta de Galicia (ED431G/09 and 2016-AD031) and the ERDF. A. F. and M. J. received F. P. U. and F. P. I. fellowships from MECD and MINECO. J. M. received a Ramon y Cajal Grant (RYC-2013-13784), an ERC Starting Investigator Grant (DYNAP-677786) and a Young Investigator Grant from the Human Frontier Research Program (RGY0066/2017) SI

Halide perovskite derivatives present unprecedented physical phenomena among those materials which are suitable for photovoltaics, such as a fast ion diffusion coefficient. In this paper it is reported how the benefits of this property can be used during the growth of halide perovskites in order to control the morphological and optoelectronic properties of the final thin film. Using a large enough halide reservoir, the nature of the halides present in the final perovskite layer can be exchanged and this depends on the initial salt used in the two-step deposition method. In particular, the preparation of a methylammonium lead bromide (MAPbBr3) thin film is reported, using a two-step method based on the transformation of lead(II) iodide (PbI2), lead(II) bromide (PbBr2) and lead(II) chloride (PbCl2) salts into MAPbBr3 perovskite after dipping in a methylammonium bromide (MABr) solution. The films prepared from different salts present different properties in terms of morphology and optoelectronic properties, thus providing significantly different performance when they are used for the preparation of photovoltaic devices. Interestingly, the use of PbI2 and PbCl2 salts reduce the charge recombination and increase the open circuit potential obtained, especially in the former case. However, the highest photocurrent is obtained when PbBr2 is used. For PbI2 and PbCl2 salts no traces of the former salt are observed in the MAPbBr3 layer obtained after 10 minutes of dipping time, however, the presence of PbBr2 has still been detected (using X-ray diffraction) when this salt has been employed.

Paper aging and protection are of crucial interest for improving the preservations of library collections and archives. Highly aging-resistant cellulose fiber sheets were obtained by treatment with magnesium hydroxide nanoparticles (Mg(OH)2). The procedure was tested on the sheets made of bleached (B) and refined unbleached (UB) pine cellulose fibers as well as their 50%/50% mixture (M). The morphological and structural properties of the obtained sheets were studied by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) methods. Stress-strain, smoothness and pH measurements were employed to determine the changes in physical-chemical characteristics of the sheets after mixing two types of the fibers and subsequent treatment with Mg(OH)2. It has been shown that the sheets made of the fiber mixture show higher tensile index and smoothness. The modification with Mg(OH)2 nanoparticles induces an increase in the pH of the sheets to slightly basic values (around pH 8), facilitates the inter-fiber bonding and additionally enhances the smoothness of the sheets. Finally, by exposing the sheets to the thermo-hygrometric accelerated artificial ageing, it was found that the physical properties of the treated sheets were not significantly dependent on the environmental factors., This study was supported by the Geomaterials 2 Programme (S2013/MIT_2914), the Innovation and Education Ministry (ref. MAT2013-47460-C5-5-P) and the Autonomous Region Program of Madrid, MULTIMAT-CHALLENGE (ref. S2013/MIT-2862).