Doped nanoparticles for optoelectronics applications

Nanoparticles of wide band gap materials doped with transition metal ions or rare earth ions are intensively studied for their possible applications in a new generation of light sources for an overhead illumination. In this work we discuss mechanisms of emission enhancement in nanoparticles doped with rare earth or/and transition metal ions. Arguments are presented that phosphors of nanosize may emit light more efficiently and thus be applied in practical optoelectronic devices

Chromium removal from aqueous solution by a PEI-silica nanocomposite

It is essential and important to determine the adsorption mechanism as well as removal efficiency when using an adsorption technique to remove toxic heavy metals from wastewater. In this research, the removal efficiency and mechanism of chromium removal by a silica-based nanoparticle were investigated. A PEI-silica nanoparticle was synthesized by a one-pot technique and exhibited uniformly well-dispersed PEI polymers in silica particles. The adsorption capacity of chromium ions was determined by a batch adsorption test, with the PEI-silica nanoparticle having a value of 183.7 mg/g and monolayer sorption. Adsorption of chromium ions was affected by the solution pH and altered the nanoparticle surface chemically. First principles calculations of the adsorption energies for the relevant adsorption configurations and XPS peaks of Cr and N showed that Cr(VI), [HCrO4](-) is reduced to two species, Cr(III), CrOH2+ and Cr3+, by an amine group and that Cr(III) and Cr(VI) ions are adsorbed on different functional groups, oxidized N and NH3+

How science spies on nature and how technology imitates nature

Od momentu powstania współczesnych nauk przyrodniczych jednym z zasadniczych problemów było podglądanie przyrody, które zawierało się w prostym pytaniu: Jak to działa? Z kolei technika, po przedstawieniu przez naukę mechanizmu działania, starała się naśladować ten zbadany fragment przyrody. Owo podglądanie, potem naśladowanie przyrody, a ogólnie wzajemne relacje: nauka-technika-przyroda nic nie straciły ze swojej aktualności do chwili obecnej. Tymi relacjami pasjonują się przedstawiciele filozofii nauki, a w szczególności filozofii nauk przyrodniczych. Książka pt. How Science Spies on and Technology Imitates Nature jest pokłosiem konferencji naukowej pod tym samym tytułem zorganizowanej na Uniwersytecie Gdańskim pod egidą Fundacji Humboldta w roku 2011. Naukowcy z kilku krajów Europy przedstawili swoje dziedziny nauki i techniki w relacji do przyrody w zamieszczonych artykułach. Zatem książka, jako zbiór artykułów, staje się interesująca również dla wszystkich osób zajmujących się filozofią nauki, a w szczególności filozofią nauk przyrodniczych. Pewnego rodzaju podsumowaniem wspomnianej konferencji była dyskusja panelowa na jej zakończenie. Tę niezwykle interesującą i gorącą dyskusję przedstawiono w książce in extenso.From the moment of the coming into existence of contemporary natural sciences peeping of the nature which was contained was one of fundamental problems in the simple question: how does it work? Next the technique, after visualising by the learning the mechanism of action, tried to imitate this examined fragment of the nature. That peeping, then imitating the nature, and generally interrelation: nauka-technika-przyroda lost nothing from their topicality by now. Representatives of philosophy of the learning, in particular philosophy of natural sciences are fascinated by these relations. Book How Science Spies Fri. he and Technology Imitates Nature is gleanings of a scientific conference under the same title organised at university Gdańsk under the aegis of Humboldt Foundation in 2011. Scientists from a few countries of Europe described their fields of the science and technology in the relation to the nature in placed articles. And so the book, as the set of articles, is also becoming interesting for all doing persons with philosophy of the learning, in particular philosophy of natural sciences. Of certain kind a panel discussion was recapitulating the recalled conference for for her finishing. This unusually interesting and heated discussion was described in the book in extenso.

Bacteriophages as Factories for Eu2O3 Nanoparticle Synthesis

The use of phage display to identify peptides with an ability to bind and synthesize Eu2O3 nanoparticles is demonstrated in this report. This is the first report of modified phages specifically binding a lanthanide. The peptides exposed on virions revealed very strong binding to Eu2O3 nanoparticles and the ability to catalyze Eu2O3 nanoparticles' formation from Eu(OH)3 and Eu(NO3)3 solutions. The luminescence emission spectrum of Eu3+ ions indicated that these ions existed mostly in sites deviated from the inversion symmetry in crystalline Eu2O3 aggregates and gelatinous Eu(OH)3 precipitate. The ability of phage-displayed peptides to catalyze formation of Eu2O3 nanoparticles provides a useful tool for a low-cost and effective synthesis of lanthanide nanoparticles, which serve as attractive biomedical sensors or fluorescent labels, among their other applications

Phage-Directed Synthesis of Photoluminescent Zinc Oxide Nanoparticles under Benign Conditions

Biological systems, especially bacteriophages and peptides, are an attractive green alternative to other known methods of nanoparticle synthesis. In this work, for the first time, bacteriophages were employed to synthesize a specific peptide, capable of producing nanoparticles (NPs). Derivatives of M13 bacteriophage exposing a ZnO-binding peptide (TMGANLGLKWPV) on either pIII or pVIII phage coat protein were constructed and used as a biotemplate. The exposition of the ZnO-binding peptide, synthesized by phages during their propagation in bacteria, on M13 virions provided a groundwork for growing ZnO nanostructures. Depending on the recombinant phage type used (M13-pIII-ZnO or M13-pVIII-ZnO), well separated ZnO NPs or complex 3D structures of ZnO NPs of ca. 20-40 nm were synthesized at room temperature. The synthesized ZnO nanoparticles served as a luminescent material that emitted light near the short wavelength end of the visible region (at ca. 400 nm). The next very low intensity emission band at 530 nm demonstrated that the ZnO material obtained is characterized by a low concentration of surface defect