Impact of graphene oxide lateral dimensions on the properties of methacrylated gelatin nanocomposite hydrogels.

The size and shape of nanoparticles have a profound effect on the properties of nanocomposites. For instance, the lateral dimensions of graphene oxide (GO) platelets affect several properties, including their antibacterial and pharmacokinetic functions. However, the impact of lateral dimensions has been poorly studied in nanocomposites, and their effect on hydrogels is still unknown.

Xanthurenic Acid in the Shell Purple Patterns of : First Evidence of an Ommochrome Metabolite in a Mollusk Shell.

Ommochromes are one of the least studied groups of natural pigments, frequently confused with melanin and, so far, exclusively found in invertebrates such as cephalopods and butterflies. In this study focused on the purple color of the shells of a mollusk, , the first evidence of a metabolite of ommochromes, xanthurenic acid (XA), was obtained by liquid chromatography combined with mass spectrometry (UPLC-MS). In addition to XA and various porphyrins previously identified, a second group of high molecular weight acid-soluble pigments (HMASP) has been identified with physicochemical and structural characteristics similar to those of ommochromes.

Nanocellulose-derived carbon/g-CN heterojunction with a hybrid electron transfer pathway for highly photocatalytic hydrogen peroxide production.

Using oxygen reduction for the photocatalytic production of hydrogen peroxide (HO) has been considered a green and sustainable route. In the present study, to achieve high efficiency, graphitic carbon nitride (g-CN) was obtained using thermal polymerization from a bi-component precursor and was then assembled with cellulose nanofibers. It was found that a small quantity of cellulose nanofibers that generates carbon fibers upon pyrolysis greatly improves the photocatalytic activity compared with that of g-CN alone.

TiO Suboxide Phases in TiO/C Nanocomposites Engineered by Non-hydrolytic Sol-Gel with Enhanced Electrocatalytic Properties.

We report a non-hydrolytic sol-gel (NHSG) route to engineer original mesoporous TiO@TiO/C nanocomposites. The synthetic approach is straightforward, solvent-free, additive-free, and meets the challenge of atom economy, as it merely involves TiCl and THF in stoichiometric amounts. We found that these nanocomposites present enhanced electrocatalytic properties towards the oxygen reduction reaction (ORR) in 0.

Glycerol-plasticized agarose separator suppressing dendritic growth in Li metal battery.

The growth of dendrite is the major limitation to the development of the Li-metal battery. To solve it, we disclose the preparation and performances of separator (MAGly) with a complete "green" formulation using biosourced and sustainable compounds: agarose as biopolymer along with glycerol as plasticizing agent. The natural biopolymer films are non-porous in nature and possess high elasticity with high stiffness along a wide temperature range (-35 to 180 °C), able to prevent the perpendicular dendritic Li growth.

Chemical evidence of rare porphyrins in purple shells of Crassostrea gigas oyster.

The colour of oyster shells is a very diverse characteristic morphotype, forming intriguing vivid patterns both on the inside and outside of the shell. In the present study, we have identified for the first time, the presence of several porphyrins as constituents of the shell pigmentation of the Crassostrea gigas oyster consumed worldwide. The precise molecular structures of halochromic, fluorescent and acid-soluble porphyrins, such as uroporphyrin and turacin, are unambiguously determined by reverse phase liquid chromatography combined with high resolution mass spectrometry.

C-nanocoated ZnO by TEMPO-oxidized cellulose templating for improved photocatalytic performance.

Ultrafine C-doped ZnO/carbon nanocomposites with different photocatalytic activities have been prepared using TEMPO-oxidized cellulose as a template but also as the source of carbon. The result is an enhancement of the photocatalytic activity ascribed to different phenomena: a high mesoporosity beneficial to mass transport, a thin carbon layer onto ZnO increasing the charge transfer and hydrophobicity of ZnO, a narrowing of ZnO band gap and an increase of the zinc (V) and oxygen (V) vacancies effectively suppressing of the charge recombination. These are evidenced by photocatalytic test of photodegradation of methyl orange (MO) achieved to assess and compared the different photocatalysts.

Key Insights, Tools, and Future Prospects on Oyster Shell End-of-Life: A Critical Analysis of Sustainable Solutions.

Oyster farming represents one of the most developed aquaculture activities, producing delicacies unfortunately related to a direct accumulation of waste shells. Facing what is becoming an environmental issue, chemists are currently developing solutions to add value to this wild source of raw material in line with the principles of sustainable chemistry. An argumentative overview of this question is proposed here with a focus on recent data.

Dehydration of Alginic Acid Cryogel by TiCl vapor: Direct Access to Mesoporous TiO @C Nanocomposites and Their Performance in Lithium-Ion Batteries.

A new strategy for the synthesis of mesoporous TiO @C nanocomposites through the direct mineralization of seaweed-derived alginic acid cryogel by TiCl through a solid/vapor reaction pathway is presented. In this synthesis, alginic acid cryogel can have multiple roles; i) mesoporous template, ii) carbon source, and iii) oxygen source for the TiO precursor, TiCl . The resulting TiO @alginic acid composite was transformed either into pure mesoporous TiO by calcination or into mesoporous TiO @C nanocomposites by pyrolysis.

Alginic acid aquagel as a template and carbon source in the synthesis of LiTiO/C nanocomposites for application as anodes in Li-ion batteries.

We report here a simple process for the synthesis of LiTiO(LTO)/carbon nanocomposites by a one-pot method using an alginic acid aquagel as a template and carbon source, and lithium acetate and TiO nanoparticles as precursors to the LTO phase. The carbon content can be tuned by adjusting the relative amount of alginic acid. The obtained materials consist of nanosized primary particles of LTO (30 nm) forming micron-sized aggregates covered by well-dispersed carbon (from 3 to 19 wt%).

Ethers as Oxygen Donor and Carbon Source in Non-hydrolytic Sol-Gel: One-Pot, Atom-Economic Synthesis of Mesoporous TiO -Carbon Nanocomposites.

Mesoporous TiO -carbon nanocomposites were synthesized using an original non-hydrolytic sol-gel (NHSG) route, based on the reaction of simple ethers (diisopropyl ether or tetrahydrofuran) with titanium tetrachloride. In this atom-economic, solvent-free process, the ether acts not only as an oxygen donor but also as the sole carbon source. Increasing the reaction temperature to 180 °C leads to the decomposition of the alkyl chloride by-product and to the formation of hydrocarbon polymers, which are converted to carbon by pyrolysis under argon.

Reductive mineralization of cellulose with vanadium, iron and tungsten chlorides and access to MO metal oxides and MO/C metal oxide/carbon composites.

MO and MO/C composites (M=V, Fe and W) were obtained by mineralization of cellulose with several metal chlorides. Cellulose was used both as a templating agent and as an oxygen and a carbon source. Soluble chloride molecules (VOCl and WCl) and a poorly soluble ionic chloride compound (FeCl) were chosen as metal oxide precursors.

Applications of bacterial cellulose as precursor of carbon and composites with metal oxide, metal sulfide and metal nanoparticles: A review of recent advances.

This mini review is limited to very recent studies (last 5-10 years) on two major issues, concerning: the production and physical/chemical modification of bacterial cellulose (BC), and its transformation into carbon and integrated synthesis of metal oxides (TiO, ZnO, FeO, etc.), metal sulfide (ZnS, CdS, etc.) and metal nanoparticles (Au, Ag, Pt, Pd, etc.

The Reductive Dehydration of Cellulose by Solid/Gas Reaction with TiCl at Low Temperature: A Cheap, Simple, and Green Process for Preparing Anatase Nanoplates and TiO /C Composites.

Metal oxides and metal oxide/carbon composites are entering the development of new technologies and should therefore to be prepared by sustainable chemistry processes. Therefore, a new aspect of the reactivity of cellulose is presented through its solid/gas reaction with vapour of titanium(IV) chloride in anhydrous conditions at low temperature (80 °C). This reaction leads to two transformations both for cellulose and titanium(IV) chloride.

Synthesis of Titania@Carbon Nanocomposite from Urea-Impregnated Cellulose for Efficient Lithium and Sodium Batteries.

Nanostructured TiO2 and TiO2@C nanocomposites were prepared directly from urea-impregnated cellulose by a simple reaction/diffusion process and evaluated as negative electrode materials for Li and Na batteries. By direct treatment with TiCl4 under anhydrous conditions, the urea impregnation of cellulose impacts both the TiO2 morphology and the carbon left by cellulose after pyrolysis. Hierarchical TiO2 structures with a flower-like morphology grown from-and-at the surface of the cellulose fibers are obtained without any directing agent.

Conversion of Nanocellulose Aerogel into TiO2 and TiO2@C Nano-thorns by Direct Anhydrous Mineralization with TiCl4. Evaluation of Electrochemical Properties in Li Batteries.

Nanostructured TiO2 and TiO2@C nanocomposites were prepared by an original process combining biotemplating and mineralization of aerogels of nanofibrillated cellulose (NFC). A direct one step treatment of NFC with TiCl4 in strictly anhydrous conditions allows TiO2 formation at the outermost part of the nanofibrils while preserving their shape and size. Such TiO2@cellulose composites can be transformed into TiO2 nanotubes (TiO2-NT) by calcination in air at 600 and 900 °C, or into TiO2@C nanocomposites by pyrolysis in argon at 600 and 900 °C.

The layered double hydroxide route to Bi-Zn co-doped TiO₂ with high photocatalytic activity under visible light.

In this work, a co-doped Bi-Zn-TiO₂ photocatalist is synthesized by an original synthesis route of layered double hydroxide followed by heat treatment at 670 °C. After characterization the photocatalyst efficiency is estimated by the photo-discoloration of an anionic dye (indigo carmine) under visible light and compare to TiO₂-P25 as reference material. In this new photocatalyst, anatase and ZnO wurtzite are the only identified crystalline phase, rutile and Bi₂O₃ being undetected.

Ordered hybrids from template-free organosilane self-assembly.

Despite considerable achievements over the last two decades, nonporous organic-inorganic hybrid materials are mostly amorphous, especially in the absence of solvothermal processes. The organosilane self-assembly approach is one of the few opportunities for creating a regular assembly of organic and inorganic moieties. Additionally, well-established organosilicon chemistry enables the introduction of numerous organic functionalities.

Surface modification of titania powder P25 with phosphate and phosphonic acids--effect on thermal stability and photocatalytic activity.

Phosphorus is frequently reported as a doping element for TiO(2) as photocatalyst; however, the previously reported methods used to prepare P-doped TiO(2) do not allow control over the location of the phosphorus either in the bulk or at the surface or both. In this study, we report on the surface modification of Evonik P25 with phosphonic (H(3)PO(3)) and octylphosphonic acid [C(8)H(17)-PO(OH)(2)], done to limit the introduction of phosphorus only to the photocatalyst surface. The effect of this element on the thermal behavior and photocatalytic properties is reported through characterization using elemental analyses, solid state (31)P NMR, X-ray powder diffraction, N(2) porosimetry, dilatometry, etc.

Brilliant molecular nanocrystals emerging from sol-gel thin films: towards a new generation of fluorescent biochips.

To develop highly sensitive biosensors, we made directly available to biological aqueous solutions organic nanocrystals previously grown in the pores of sol-gel films. Through the controlled dissolution of the sol-gel surface, we obtained emerging nanocrystals that remained strongly anchored to the sol-gel coating for good mechanical stability of the final sensing device. We demonstrated that in the presence of a solution of DNA functionalized with a molecular probe, the nanocrystal fluorescence is strongly quenched by Förster resonance energy transfer thus opening the way towards very sensitive fluorescent biosensors through biomolecules grafted onto fluorescent nanocrystals.

Polymorphs and colors of polydiacetylenes: a first principles study.

Polydiacetylenes (PDAs) are exceptional polymeric materials with pi-conjugated backbones. Several of them can undergo chromogenic transitions under a wide range of external stimuli. Herein we investigate the electronic structure and the resulting properties of model and experimental PDAs, by means of first principles condensed matter calculations.

Molecular assemblies from imidazolyl-containing haloalkenes and haloalkynes: competition between halogen and hydrogen bonding.

The structural characterization of molecular assemblies constructed from imidazolyl-containing haloalkenes and haloalkynes is reported. 1-(3-Iodopropargyl)imidazole (2) and 1-(2,3,3-triiodoallyl)imidazole (5) were synthesized from 1-propargylimidazole (1). In the solid state, these wholly organic modules self-assemble through N.

Functional organotrimethoxysilane derivative with strong intermolecular pi-pi interaction: one-pot grafting reaction on oxidized silicon substrates.

Although the fabrication of self-assembled monolayers (SAMs) on an oxidized silicon substrate with special functionality is an important topic for various applications, it is still very difficult to obtain a densely grafted monolayer. With a newly synthesized organotrimethoxysilane containing a 1-cyano-1,2-bisbiphenyl-ethylene (CNMBE) moiety which provides a strong pi-pi intermolecular interaction, an SAM of well-ordered structure is readily obtained by a one-pot grafting reaction under mild conditions. The aggregation process of the CNMBE moiety, which induced a close packing of organosilane on the substrate, was visually monitored by the fluorescence of the monolayer grafted on quartz.