The d(10) route to dye-sensitized solar cells: step-wise assembly of zinc(II) photosensitizers on TiO2 surfaces

Dye-sensitized solar cells have been assembled using a sequential approach: a TiO2 surface was functionalized with an anchoring ligand, followed by metallation with Zn(OAc)(2) or ZnCl2, and subsequent capping with a chromophore functionalized 2,2`:6`,2 ``-terpyridine; the DSCs exhibit surprisingly good efficiencies confirming the effectiveness of the new strategy for zinc-based DSC fabrication

Functionalized adamantane: fundamental building blocks for nanostructure self-assembly

We report first principles calculations on the electronic and structural properties of chemically functionalized adamantane molecules, either in isolated or crystalline forms. Boron and nitrogen functionalized molecules, aza-, tetra-aza-, bora-, and tetra-bora-adamantane, were found to be very stable in terms of energetics, consistent with available experimental data. Additionally, a hypothetical molecular crystal in a zincblende structure, involving the pair tetra-bora-adamantane and tetra-aza-adamantane, was investigated. This molecular crystal presented a direct and large electronic bandgap and a bulk modulus of 20 GPa. The viability of using those functionalized molecules as fundamental building blocks for nanostructure self-assembly is discussed

DNA-coated Functional Oil Droplets

Many industrial soft materials often include oil-in-water (O/W) emulsions at the core of their formulations. By using tuneable interface stabilizing agents, such emulsions can self-assemble into complex structures. DNA has been used for decades as a thermoresponsive highly specific binding agent between hard and, recently, soft colloids. Up until now, emulsion droplets functionalized with DNA had relatively low coating densities and were expensive to scale up. Here a general O/W DNA-coating method using functional non-ionic amphiphilic block copolymers, both diblock and triblock, is presented. The hydrophilic polyethylene glycol ends of the surfactants are functionalized with azides, allowing for efficient, dense and controlled coupling of dibenzocyclooctane functionalized DNA to the polymers through a strain-promoted alkyne-azide click reaction. The protocol is readily scalable due to the triblock's commercial availability. Different production methods (ultrasonication, microfluidics and membrane emulsification) are used with different oils (hexadecane and silicone oil) to produce functional droplets in various size ranges (sub-micron, $\sim 20\,\mathrm{\mu m}$ and $> 50\,\mathrm{\mu m}$), showcasing the generality of the protocol. Thermoreversible sub-micron emulsion gels, hierarchical "raspberry" droplets and controlled droplet release from a flat DNA-coated surface are demonstrated. The emulsion stability and polydispersity is evaluated using dynamic light scattering and optical microscopy. The generality and simplicity of the method opens up new applications in soft matter and biotechnological research and industrial advances.Comment: 7 pages, 2 figures, 1 tabl

Deposition and transport of functionalized carbon nanotubes in water-saturated sand columns

Knowledge of the fate and transport of functionalized carbon nanotubes (CNTs) in porous media is crucial to understand their environmental impacts. In this study, laboratory column and modeling experiments were conducted to mechanistically compare the retention and transport of two types of functionalized CNTs (i.e., single-walled nanotubes and multi-walled nanotubes) in acid-cleaned, baked, and natural sand under unfavorable conditions. The CNTs were highly mobile in the acid-cleaned sand columns but showed little transport in the both natural and baked sand columns. In addition, the retention of the CNTs in the both baked and natural sand was strong and almost irreversible even after reverse, high-velocity, or surfactant flow flushing. Both experimental and modeling results showed that pH is one of the factors dominating CNT retention and transport in natural and baked sand. Retention of the functionalized CNTs in the natural and baked sand columns reduced dramatically when the system pH increased. Our results suggest that the retention and transport of the functionalized CNTs in natural sand porous media were mainly controlled by strong surface deposition through the electrostatic and/or hydrogen-bonding attractions between surface function groups of the CNTs and metal oxyhydroxide impurities on the sand surfaces

Exploring the Charge Localization and Band Gap Opening of Borophene: A First-Principles Study

Recently synthesized two-dimensional (2D) boron, borophene, exhibits a novel metallic behavior rooted in the s-p orbital hybridization, distinctively different from other 2D materials such as sulfides/selenides and semi-metallic graphene. This unique feature of borophene implies new routes for charge delocalization and band gap opening. Herein, using first-principles calculations, we explore the routes to localize the carriers and open the band gap of borophene via chemical functionalization, ribbon construction, and defect engineering. The metallicity of borophene is found to be remarkably robust against H- and F-functionalization and the presence of vacancies. Interestingly, a strong odd-even oscillation of the electronic structure with width is revealed for H-functionalized borophene nanoribbons, while an ultra-high work function (~ 7.83 eV) is found for the F-functionalized borophene due to its strong charge transfer to the atomic adsorbates

Interfacial Morphology Addresses Performance of Perovskite Solar Cells Based on Composite Hole Transporting Materials of Functionalized Reduced Graphene Oxide and P3HT

The development of novel hole transporting materials (HTMs) for perovskite solar cells (PSCs) that can enhance device's reproducibility is a largely pursued goal, even to the detriment of a very high efficiency, since it paves the way to an effective industrialization of this technology. In this work, we study the covalent functionalization of reduced graphene oxide (RGO) flakes with different organic functional groups with the aim of increasing the stability and homogeneity of their dispersion within a poly(3-hexylthiophene) (P3HT) HTM. The selected functional groups are indeed those recalling the two characteristic moieties present in P3HT, i.e., the thienyl and alkyl residues. After preparation and characterization of a number of functionalized RGO@P3HT blends, we test the two containing the highest percentage of dispersed RGO as HTMs in PSCs and compare their performance with that of pristine P3HT and of the standard Spiro-OMeTAD HTM. Results reveal the big influence of the morphology adopted by the single RGO flakes contained in the composite HTM in driving the final device performance and allow to distinguish one of these blends as a promising material for the fabrication of highly reproducible PSCs

Indometacin loading and in vitro release properties from novel carbopol coated spherical mesoporous silica nanoparticles

Spherical MCM-41 silica nanosized particles were synthesized and post synthesis modified by 3-aminopropyltriethoxysilane (APTES) in order to prepare amino-functionalized carrier. Both types of silica particleswere loaded with indometacin and further coated with carbopol. The preservation of morphology and pore structure of the particles was observed by XRD, TEM and N2 physisorption. FT-IR spectroscopy revealed the interaction between carboxyl groups of indometacin and the amino groups of the functionalized MCM-41. Amino-functionalization of the carrier resulted in higher degree of indometacin loading in comparison to the parent MCM-41, 39% vs. 30%, respectively. The coating of drug loaded amino-MCM-41 silica particles with carbopol significantly reduced the initial burst release of indometacin. Both silica carriers demonstrated no cytotoxicity on HL-60 (acute myeloid leukemia) and K-562 (chronic myeloid leukemia) cell lines