Since the 1950’s, synthetic organic polymers have been widely used as consolidants for the preservation of historic stones, altered by the weather conditions. Although still in use, their conservation efficiency has been drastically reconsidered due to their fugitiveness, thermo- and photo-degradation, limited removability, and incompatibility with the stone matrix. Synthetic organic polymers are thus believed to be harmful in the long term and unsuitable materials for the consolidation of historic stone.

Inorganic materials such as alkaline earth hydroxides are better suited for the task due to their higher physicochemical compatibility with the rocks, but mostly exist as isolated particles acting as fillers only, rather than offering a continuous medium that would ensure an optimal adhesion between the newly produced carbonate and the weathered stone.

Now, Bingjian Zhang and his team at the University of Zhejiang and Tianshui (China) have solved the adhesion issue and developed for the first time a biomimetic approach for the reinforcement of weathered stones. Their strategy was to mimic the growth of bones, by introducing calcium and phosphore sources in the pores of the damaged stone, and then let them mineralize in the presence of collagen at ambient temperature. This biomimetic mineralization process allows a porous and interlinked reinforcing phase of apatite to be formed, which can bind the grains of loose weathered calcareous stone together and provide substantial reinforcement. The team also showed that the breathing function of the stones was retained, due to the porous nature of bone-like apatite. With the highly positive results achieved, this method is promising for the conservation of historic stones, say the researchers, while further challenges lie towards a reinforcement method aimed at non-calcareous rocks.

Biomimic conservation of weathered calcareous stones by apatite
Fuwei Yang, Bingjian Zhang, Yan Liu, Guofeng Wei, Hui Zhang, Weixiang Chen and Zhude Xu
New J. Chem., 2011, Advance Article
DOI: 10.1039/C0NJ00783H, Paper

A native enzyme, which catalyzes stereoselective aldol reactions, was successfully encapsulated in an inorganic support by Forano, Lemaire, and co-workers. This biocatalyst maintains 100% of enzyme activity through a series of different condensation reactions. In addition, the immobilized enzyme is stable under storage and can be reused several times without a notable loss of activity, highlighting its suitability for organic synthesis.

Efficient immobilization of fructose-6-phosphate aldolase in layered double hydroxide: improved stereoselective synthesis of sugar analogues
Christine Guérard-Hélaine, Bertrand Légeret, Carlos Fernandes, Vanessa Prévot, Claude Forano and Marielle Lemaire
New J. Chem., 2011, Advance Article
DOI: 10.1039/C0NJ00956C, Letter

Curious? Why not read all about it here. This NJC paper has been rated as ‘hot’ and is FREE to access to all for a period of four weeks, after a simple registration process at: http://pubs.rsc.org/en/account/register. Let us know your thoughts and comments below!

Meisel and co-workers (University of Florida, USA) report on the elaboration of thin films of a series of Prussian Blue analogs, together with their magnetic behaviour. These films were shown to exhibit magnetic anisotropy by investigating the magnetic susceptibility, and specifically the difference between parallel and perpendicular orientations of the films with respect to the applied magnetic field. The degree of anisotropy is largely explained by demagnetizing effects, and a simple model is discussed. This paper represents a first step towards the understanding of the anisotropy of thin films of coordination polymer systems, of importance if films are to be used in device applications. Furthermore, this manuscript casts light on the origin of the anisotropy of photomagnetic systems.

Anisotropic magnetism in Prussian blue analogue films
Daniel M. Pajerowski, Justin E. Gardner, Daniel R. Talham and Mark W. Meisel
New J. Chem., 2011, Advance Article
DOI: 10.1039/C0NJ00841A, Paper

Scientists from the universities of Sao Paulo and Thueringen present a new methodology for uphill energy conversion, converting red irradiation light into blue emission light using the instability of 1,2-dioxetanes and converting chemical energy into electronic excitation energy.

Chemiluminescence-based uphill energy conversion
Luiz Francisco Monteiro Leite Ciscato, Dieter Weiss, Rainer Beckert, Erick Leite Bastos, Fernando Heering Bartoloni and Wilhelm Josef Baader
New J. Chem., 2011, Advance Article
DOI: 10.1039/C0NJ00843E, Letter

Curious? Why not read this NJC Letter, FREE to access until March 14th 2011

In this NJC Hot article, read about the use of electrostatic spray deposition to form dense, thin and crack-free gadolinium-doped ceria films, for use as a barrier layers in solid oxide fuel cells.

Elaboration of thin and dense CGO films adherent to YSZ by electrostatic spray deposition for IT-SOFC applications, Cécile Rossignol, Benjamin Roman, Guilherme David Benetti and Elisabeth Djurado, New J. Chem., 2011, Advance Article, DOI: 10.1039/C0NJ00570C, Paper

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In this NJC Hot Article, Lajos Kovács and colleagues consider the aggregation of 3-methylxanthine via experimental and theoretical approaches and show the formation of quartet sytems, revealing that 3-substituted xanthines could be a previously undescribed quadruplex-forming base.

3-Substituted xanthines as promising candidates for quadruplex formation: computational, synthetic and analytical studies, János Szolomájer, Gábor Paragi, Gyula Batta, Célia Fonseca Guerra, F. Matthias Bickelhaupt, Zoltán Kele, Petra Pádár, Zoltán Kupihár and Lajos Kovács, New J. Chem., 2011, Advance Article, DOI: 10.1039/C0NJ00612B, Paper

Curious? Why not read all about it here. This NJC paper has been rated as ‘hot’ and is FREE to access to all for a period of four weeks, after a simple registration process at: http://pubs.rsc.org/en/account/register. Let us know your thoughts and comments below!

In this hot article, Jonathan S. Lindsey and colleagues have looked at the hypothetical pre-biotic synthesis of tetrapyrroles and designed an enzyme free synthesis of nature’s universal precursor to the ‘pigments of life’ (corrins, heme, chlorophylls), in which the abiotic reaction under mild conditions of δ-aminolevulinic acid and the dione shown gives uroporphyrinogen.

Abiotic formation of uroporphyrinogen and coproporphyrinogen from acyclic reactants, Jonathan S. Lindsey, Vanampally Chandrashaker, Masahiko Taniguchi and Marcin Ptaszek, New J. Chem., 2011, Advance Article, DOI: 10.1039/C0NJ00716A, Paper

Curious about porphyrinoids, prebiotic chemistry and the origins of life? Then why not read the article for free until 7th January 2011 and let us know your thoughts and comments below.

In this NJC Letter, Farrusseng and coworkers report on the guest-induced reversible gate-opening of a zeolite imidazolate framework (ZIF-7 and ZIF-8) and explore in detail the thermodynamics beyond these phenomena. This Letter was highly rated by the reviewers and selected as a Hot article by the editors, offering FREE access to the article for a period of 4 weeks.

Guest-induced gate-opening of a zeolite imidazolate framework, Sonia Aguado, Gérard Bergeret, Marc Pera Titus, Virginie Moizan, Carlos Nieto-Draghi, Nicolas Bats and David Farrusseng, New J. Chem., 2011, Advance Article, DOI: 10.1039/C0NJ00836B, Letter

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