Algal polysaccharides for 3D printing: A review.

Algae hold particular promise as a feedstock for biomaterials, as they are capable of producing a wide variety of polymers with the properties required for 3D printing. However, the use of algal polymers has been limited to alginate, agar, carrageenan, and ulvan extracted from seaweeds. Diverse algal taxa beyond seaweeds have yet to be explored. In this comprehensive review, we discuss available algal biomaterials, their properties, and emerging applications in 3D printing techniques. We also identify elite algal strains to be used in 3D printing and comment on both advantages and limitations of algal biomass as a printing material. Global 3D printing market trends and material demands are also critically analyzed. Finally, the future prospects, opportunities, and challenges for using algal polymers in 3D printing market for a sustainable economy are discussed. We hope this review will provide a foundation for exploring the 3D printable biomaterials from algae.

Nucleic acid isothermal amplification-based soft nanoarchitectonics as an emerging electrochemical biosensing platform.

The emergence of nucleic acid isothermal amplification strategies based on soft nanoarchitectonics offers a new dimension to the traditional electrochemical technique, particularly because of its flexibility, high efficiency, and increased sensitivity for analytical applications. Various DNA/RNA isothermal amplification strategies have been developed for the design and fabrication of new electrochemical biosensors for efficient and important biomolecular detection. Herein, we provide an overview of recent efforts in this research field and the strategies for signal-amplified sensing systems, with their biological applications, current challenges and prospects in this promising new area.

Biochar for delivery of agri-inputs: Current status and future perspectives.

Biochar, a carbonaceous porous material produced from the pyrolysis of agricultural residues and solid wastes has been widely used as a soil amendment. Recent publications on biochar are primarily focussed with its application in climatic aspects, contaminant immobilization, soil amendment strategies, nutrient recovery, engineered material production and waste-water treatment. Numerous studies have reported the positive attribute of biochar's nutrient value that helps in improving plant growth and fertilizer use efficiency. The renewability, low-cost, high porosity, high surface area and customizable surface chemistry of biochar offers ample prospect in several engineering applications, some of which needs significant attention. This review aims at systematically assessing the uses of biochar as a potential carrier material for delivery of agrochemicals and microbes. The key parameters of biochar that are crucial to assess the potential of any material to be used for delivery purposes are discussed. The parameters such as the physicochemical properties of biochar, the mechanistic aspects of adsorption and release of agrochemicals and microbes from biochar, comparative assessment of biochar over other carrier materials, long-term effects of biochar and the economic and environmental benefits of biochar are discussed in detail. At the end, a brief perspective has also been laid out to discuss how nano-interventions could further be helpful to tailor biochar properties useful for delivery applications.

Electrophoretic deposited TiO(2) pigment-based back reflectors for thin film solar cells.

Highly reflective coatings with strong light scattering effect have many applications in optical components and optoelectronic devices. This work reports titanium dioxide (TiO(2)) pigment-based reflectors that have 2.5 times higher broadband diffuse reflection than commercially produced aluminum or silver based reflectors and result in efficiency enhancements of a single-junction amorphous Si solar cell. Electrophoretic deposition is used to produce pigment-based back reflectors with high pigment density, controllable film thickness and site-specific deposition. Electrical conductivity of the pigment-based back reflectors is improved by creating electrical vias throughout the pigment-based back reflector by making holes using an electrical discharge / dielectric breakdown approach followed by a second electrophoretic deposition of conductive nanoparticles into the holes. While previous studies have demonstrated the use of pigment-based back reflectors, for example white paint, on glass superstrate configured thin film Si solar cells, this work presents a scheme for producing pigment-based reflectors on complex shape and flexible substrates. Mechanical durability and scalability are demonstrated on a continuous electrophoretic deposition roll-to-roll system which has flexible metal substrate capability of 4 inch wide and 300 feet long.

Iodized BODIPY as a long wavelength light sensitizer for the near-infrared emission of ytterbium(III) ion.

Novel 8-HOQ-BODIPY-3I was developed as an efficient sensitizer for the near-infrared emission of ytterbium(III) ion at 980 nm under long wavelength excitation.

TiO2 nanotube membranes on transparent conducting glass for high efficiency dye-sensitized solar cells.

Crack-free TiO(2) nanotube (NT) membranes were obtained by short time re-anodization of a sintered TiO(2) NT array on Ti foil, followed by dilute HF etching at room temperature. The resulting freestanding TiO(2) membranes were opaque with a slight yellow color having one end open and another end closed. The membranes were then fixed on transparent fluorine-tin-oxide glass using a thin layer of screen-printed TiO(2) nanoparticles (NPs) as a binding medium. It was found that low temperature treatment of the resulting NT/NP film under appropriate pressure before sintering at 450 °C was critical for successful fixation of the NT membrane on the NP layer. The resulting films with open-ends of NT membranes facing the NP layer (open-ends down, OED, configuration) exhibited better interfacial contact between NTs and NPs than those with closed-ends facing the NP layer (closed-ends down, CED, configuration). The cells with an OED configuration exhibit higher external quantum efficiency, greater charge transfer resistance from FTO/TiO(2) to electrolyte, and better dye loading compared to CED configurations. The solar cells with the OED configuration gave 6.1% energy conversion efficiency under AM1.5G condition when the commercial N719 was used as a dye and I(-)/I(3)(-) as a redox couple, showing the promise of this method for high efficiency solar cells.

Hybridization of near-infrared emitting erbium(III) and ytterbium(III) monoporphyrinate complexes with silica xerogel: synthesis, structure and photophysics.

The new erbium(III) and ytterbium(III) monoporphyrinate complexes were synthesized and hybridized into silica xerogel frameworks though the coordination of 5-(N,N-bis(3-propyl)ureyl-1,10-phenanthroline to the lanthanide ions. The complexes are eight-coordinate with strong emissions in solution in the near-infrared region. The resulting silica films are transparent, homogenous, and exhibit strong mechanical strength. The scanning electron microscope and atomic force microscope study reveals that the surface of the film is porous with the silica in particulate or rod shapes. Upon visible light excitation, the fluorescence of the porphyrin at approximately 649 nm with lifetimes of approximately 3.4 and 3.8 ns for erbium(III) and ytterbium-hybridized films were observed, respectively. The erbium- and ytterbium-hybridized films gave characteristic emissions at 1538 nm with a lifetime of 0.6 micros and at 980 nm with a lifetime of 6.6 micros, respectively. They exhibited a 50 to 70% decrease in lifetime compared to their parent complexes in toluene.