Towards Room Temperature Thermochromic Coatings with controllable NIR-IR modulation for solar heat management & smart windows applications.

Solar heat management & green air-conditioning are among the major technologies that could mitigate heat islands phenomenon while minimizing significantly the CO2 global foot-print within the building & automotive sectors. Chromogenic materials in general, and thermochromic smart coatings especially are promising candidates that consent a noteworthy dynamic solar radiation Infrared (NIR-IR) regulation and hence an efficient solar heat management especially with the expected increase of the global seasonal temperature. Within this contribution, two major challenging bottlenecks in vanadium oxide based smart coatings were addressed. It is validated for the first time that the NIR-IR modulation of the optical transmission (∆TTRANS = T(T〈TMIT) - T(T〉TMIT) of Vanadium oxide based smart coatings can be controlled & tuned. This upmost challenging bottle-neck controllability/tunability is confirmed via a genuine approach alongside to a simultaneous drastic reduction of the phase transition temperature TMIT from 68.8 °C to nearly room temperature. More precisely, a substantial thermochromism in multilayered V2O5/V/V2O5 stacks equivalent to that of standard pure VO2 thin films but with a far lower transition temperature, is reported. Such a multilayered V2O5/V/V2O5 thermochromic system exhibited a net control & tunability of the optical transmission modulation in the NIR-IR (∆TTRANS) via the nano-scaled thickness' control of the intermediate Vanadium layer. In addition, the control of ∆TTRANS is accompanied by a tremendous diminution of the thermochromic transition temperature from the elevated bulk value of 68.8 °C to the range of 27.5-37.5 ºC. The observed remarkable and reversible thermochromism in such multilayered nano-scaled system of V2O5/V/V2O5 is likely to be ascribed to a noteworthy interfacial diffusion, and an indirect doping by alkaline ions diffusing from the borosilicate substrate. It is hoped that the current findings would contribute in advancing thermochromic smart window technology and their applications for solar heat management in glass windows in general, skyscraper especially & in the automotive industry. If so, this would open a path to a sustainable green air-conditioning with zero-energy input.

Room temperature bio-engineered multifunctional carbonates for CO2 sequestration and valorization.

This contribution reports, for the first time, on an entirely green bio-engineering approach for the biosynthesis of single phase crystalline 1-D nano-scaled calcite CaCO3. This was validated using H2O as the universal solvent and natural extract of Hyphaene thebaica fruit as an effective chelating agent. In this room temperature green process, CaCl2 and CO2 are used as the unique source of Ca and CO3 respectively in view of forming nano-scaled CaCO3 with a significant shape anisotropy and an elevated surface to volume ratio. In terms of novelty, and relatively to the reported scientific and patented literature in relation to the fabrication of CaCO3 by green nano-chemistry, the current cost effective room temperature green process can be singled out as per the following specificities: only water as universal solvent is used, No additional base or acid chemicals for pH control, No additional catalyst, No critical or supercritical CO2 usage conditions, Only natural extract of thebaica as a green effective chelating agent through its phytochemicals and proper enzematic compounds, room Temperature processing, atmospheric pressure processing, Nanoscaled size particles, and Nanoparticles with a significant shape anisotropy (1-D like nanoparticles). Beyond and in addition to the validation of the 1-D synthesis aspect, the bio-engineered CaCO3 exhibited a wide-ranging functionalities in terms of highly reflecting pigment, an effective nanofertilizer as well as a potential binder in cement industry.

Physical properties of computationally informed phyto-engineered 2-D nanoscaled hydronium jarosite.

This study describes a molecular dynamics computational modelling informed bioengineering of nano-scaled 2-D hydronium jarosite. More specifically, a phyto-engineering approach using green nano-chemistry and agro-waste in the form of avocado seed natural extract was utilized as a green, economic, and eco-friendly approach to synthesize this unique mineral at the nanoscale via the reduction of iron (II) sulphate heptahydrate. The nanoproduct which was found to exhibit a quasi-2D structure was characterized using a multi-technique approach to describe its morphological, optical, electrochemical, and magnetic properties. Radial distribution function and electrostatic potential maps revealed that flavone, a phenolic compound within the avocado seed natural extract, has a higher affinity of interaction with the nanoparticle's surface, whilst vanillic acid has a higher wetting tendency and thus a lower affinity for interacting with the hydronium jarosite nanoparticle surface compared to other phytoactive compounds. XRD and HRTEM results indicated that the nanoscale product was representative of crystalline rhombohedral hydronium jarosite in the form of quasi-triangular nanosheets decorated on the edges with nanoparticles of approximately 5.4 nm diameter that exhibited significant electrochemical and electroconductive behaviours. Magnetic studies further showed a diamagnetic behaviour based on the relationship of the inverse susceptibility of the nanomaterial with temperature sweep.

On the remarkable nonlinear optical properties of natural tomato lycopene.

In line with the renewed interest in developing novel Non Linear Optical (NLO) materials, natural Lycopene's NLO Properties are reported for the first time within the scientific literature. Correlated to its 1-D conjugated π-electrons linear conformation, it is shown that natural Lycopene exhibits a significantly elevated 3rd order nonlinearity χ(3) as high as 2.65 10-6 esu, the largest value of any investigated natural phyto-compound so far, including ß-carotene. In addition to a saturable absorption, the corresponding observed self-defocusing effect in Lycopene seems to be the result of a thermal nonlinearity. The nonlinear response coupled to the observed fluorescence in the Visible spectral range points to a potential photodynamic therapy application as well as the possibility of engineering of novel hybrid Lycopene based NLO nano-materials.

Mercury goes Solid at room temperature at nanoscale and a potential Hg waste storage.

While room temperature bulk mercury is liquid, it is solid in its nano-configuration (Ønano-Hg ≤ 2.5 nm). Conjugating the nano-scale size effect and the Laplace driven surface excess pressure, Hg nanoparticles of Ønano-Hg ≤ 2.4 nm embedded in a 2-D turbostratic Boron Nitride (BN) host matrix exhibited a net crystallization at room temperature via the experimentally observed (101) and (003) diffraction Bragg peaks of the solid Hg rhombohedral α-phase. The observed crystallization is correlated to a surface atomic ordering of 7 to 8 reticular atomic plans of the rhombohedral α-phase. Such a novelty of size effect on phase transition phenomena in Hg is conjugated to a potential Hg waste storage technology. Considering the vapor pressure of bulk Hg, Room Temperature (RT) Solid nano-Hg confinement could represent a potential green approach of Hg waste storage derived from modern halogen efficient light technology.

Comparison of Effects of Hemostatic Gelatin Sponge Impregnated with Ropivacaine versus Normal Saline Applied on the Transverse Process of the Operated Vertebrae on Postoperative Pain in Patients Undergoing Spinal Instrumentation Surgery: A Randomized Clinical Trial.

BACKGROUND: Protocols for effective postoperative pain control in patients undergoing spinal surgery are not standardized. In our study, we compared the effects of hemostatic absorbable gelatin sponge impregnated with ropivacaine versus normal saline when applied to the transverse process of the operated vertebrae on the postoperative pain following instrumentation spine surgery. METHODS: A prospective double-blind randomized study was conducted on 30 patients undergoing spine surgery. At the end of surgery, the hemostatic gelatin sponge was applied by the surgeon on the transverse process of the operated vertebra containing either ropivacaine 0.5% or normal saline NaCl 0.9. Pain was assessed using the visual analog scale (VAS) every 4 hours for 48 hours postoperatively in the 2 groups (ropivacaine vs. normal saline). The total amount of postoperative opioid use was also recorded. RESULTS: The VAS score was significantly lower in patients receiving hemostatic gelatin sponge impregnated with local anesthetics as compared with patients receiving gelatin sponge impregnated with normal saline 48 hours postoperatively; the mean total dose of meperidine given in the first 48 hours postoperatively was significantly lower (53.5 ± 51.0 mg) in patients receiving gelatin sponge impregnated with local anesthetics as compared with patients receiving hemostatic gelatin sponge impregnated with normal saline (140.5 ± 102 mg). CONCLUSIONS: Use of intraoperative hemostatic gelatin sponge impregnated with ropivacaine applied on the transverse process of the operated vertebrae intraoperatively resulted in decreasing the postoperative pain in patients undergoing lumbar instrumentation surgery as manifested by the decrease in the VAS score and the total dose of opioids.

Elbow Cystic Lymphangioma in an 8-Month-Old Boy.

Cystic lymphangiomas are benign tumors originating mainly in the head and neck of the pediatric population. The authors report a rare case of cystic lymphangioma in the right elbow of an 8-month-old baby treated successfully by complete surgical resection.