Using Gold Nanoparticles as Passive Sampler for Indoor Monitoring of Gaseous Elemental Mercury

This study reports a functional passive sampler for monitoring gaseous elemental mercury (GEM). The material consists of gold nanoparticles (AuNP) deposited forming a film on thiol-modified glass slides. AuNP colloid was synthesized using sodium citrate, resulting in a size of 24.2 +/- 0.8 nm, as determined by transmission electron microscopy analysis. For the indoor test, AuNP films were placed into Petri plates. One part of the lot was kept exposed to the laboratory's atmosphere and the other part was stored in closed plate (control). The films were removed from both plates along a month and analyzed using a direct mercury analyzer. A linear relationship between Hg retention and exposure time was obtained until the 23(rd) day, which allowed to calculate a GEM retention rate of 2.2 ng g(-1) day(-1)the maximum retention capacity was around 50 ng g(-1). This study provides an efficient method for indoor monitoring of GEM using AuNP films as passive sampler.FAPESPCNPqFAPESPCAPESUniv Fed Sao Paulo UNIFESP, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Do Campos, SP, BrazilUniv Estadual Campinas UNICAMP, Inst Quim, POB 6154, BR-13083970 Campinas, SP, BrazilUniv Estadual Campinas UNICAMP, Inst Quim, Lab Mat Funcionais, POB 6154, BR-13083970 Campinas, SP, BrazilUniv Fed Sao Paulo UNIFESP, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Do Campos, SP, BrazilFAPESP: 2012/19485-1CNPqFAPESPCAPESWeb of Scienc

Temperature probing and emission color tuning by morphology and size control of upconverting β-NaYb0.67Gd0.30F4:Tm0.015:Ho0.015 nanoparticles

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe chemical composition, shape and size of upconverting nanoparticles are known to have a great influence on their spectroscopic properties, such as the emission color and the emission intensity variation as a function of temperature. This work shows the52CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOsem informaçãosem informação2013/22127-

In vitro and in vivo osteogenic potential of niobium-doped 45S5 bioactive glass:A comparative study

In vitro and in vivo experiments were undertaken to evaluate the solubility, apatite-forming ability, cytocompatibility, osteostimulation, and osteoinduction for a series of Nb-containing bioactive glass (BGNb) derived from composition of 45S5 Bioglass. Inductively coupled plasma optical emission spectrometry (ICP-OES) revealed that the rate at which Na, Ca, Si, P, and Nb species are leached from the glass decrease with the increasing concentration of the niobium oxide. The formation of apatite as a function of time in simulated body fluid was monitored by 31P Magic Angle Spinning (MAS) Nuclear magnetic resonance spectroscopy. Results showed that the bioactive glasses: Bioglass 45S5 (BG45S5) and 1 mol%-Nb-containing-bioactive glass (BGSN1) were able to grow apatite layer on their surfaces within 3 h, while glasses with higher concentrations of Nb2O5 (2.5 and 5 mol%) took at least 12 h. Nb-substituted glasses were shown to be compatible with bone marrow-derived mesenchymal stem cells (BMMSCs). Moreover, the bioactive glass with 1 mol% Nb2O5 significantly enhanced cell proliferation after 4 days of treatment. Concentrations of 1 and 2.5 mol% Nb2O5 stimulated osteogenic differentiation of BMMSCs after 21 days of treatment. For the in vivo experiments, trial glass rods were implanted into circular defects in rat tibia in order to evaluate their osteoconductivity and osteostimulation. Two morphometric parameters were analyzed: (a) thickness of new-formed bone layer and (b) area of new-formed subperiostal bone. Results showed that BGNb bioactive glass is osteoconductive and osteostimulative. Therefore, these results indicate that Nb-substituted glass is suitable for biomedical applications

Morphosynthesis: high fidelity inorganic replica of the fibrous network of loofa sponge (Luffa cylindrica)

High fidelity calcium carbonate and hydroxyapatite (bio) inorganic replicas of the fibrous network of the dried fruit of Luffa cylindrica are described, utilizing a facile synthetic route. The loofa sponge is a highly complex macroscopic architectural template, an inexpensive and sustainable resource. In the context of the morphosynthesis, the capability of replication of the loofa sponge opens the possibility of the use of biodiversity in obtaining new materials. We would like to emphasize that the template proposed in this paper, makes possible the preparation of inorganic replicas with a very desirable size, on the centimeter scale. This fact is innovative with respect to inorganic replicas described in the literature, which predominate at the micrometric scale, limited to the original size of the template.Réplicas (bio) inorgânicas de carbonato de cálcio e de hidroxiapatita, com elevada fidelidade à morfologia fibrosa do fruto seco da espécie Luffa cylindrica são descritas, utilizando uma rota de síntese simples e de baixo custo. A esponja vegetal é um molde macroscópico com arquitetura altamente complexa, de baixo custo e de fonte renovável. Dentro do contexto da morfossíntese, a capacidade de replicação da Luffa cylindrica acena com a possibilidade de uso da biodiversidade na obtenção de novos materiais. Enfatizamos que o molde proposto neste trabalho possibilita a preparação de réplicas inorgânicas com o tamanho desejado, em uma escala de centímetros. Este fato é inovador em relação as réplicas inorgânicas descritas na literatura, nas quais predominam a escala micrométrica, limitadas ao tamanho original do molde.2531Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Morphosynthesis: High Fidelity Inorganic Replica Of The Fibrous Network Of Loofa Sponge (luffa Cylindrica).

High fidelity calcium carbonate and hydroxyapatite (bio) inorganic replicas of the fibrous network of the dried fruit of Luffa cylindrica are described, utilizing a facile synthetic route. The loofa sponge is a highly complex macroscopic architectural template, an inexpensive and sustainable resource. In the context of the morphosynthesis, the capability of replication of the loofa sponge opens the possibility of the use of biodiversity in obtaining new materials. We would like to emphasize that the template proposed in this paper, makes possible the preparation of inorganic replicas with a very desirable size, on the centimeter scale. This fact is innovative with respect to inorganic replicas described in the literature, which predominate at the micrometric scale, limited to the original size of the template.7725-3

Self-supported films of poly(methyl methacrylate) (PMMA) containing Tm-III-doped upconverting core@shell nanoparticles as high sensitivity temperature optical probe

In this work, we describe the synthesis, and thermal sensitivity of a composite material containing NaYbF4:Gd:Tm:Ho@NaYF4:Yb Ln-UCNP dispersed in PMMA matrix. The LIR between Tm3+ upconversion emissions at 450 and 475 nm resulted in a high relative thermal sensitivity of 2.8% K-1 at 313 K and an operational range higher than 100 K (from 200 to 313 K) which is not very explored in the literature. The upconversion emission intensity variation as a function of the pump power, provided a suggestion for the emission mechanism of Tm3+, which corroborates with the high obtained thermal sensitivity. The easy manipulation as well as its high sensitivity and large operational range shows the potential of this material to be used as thermal sensor into a temperature range of interest in aerospacial research29116CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão tem2013/22127-2; 2014/50906-

The effect of 4-halogenobenzoate ligands on luminescent and structural properties of lanthanide complexes: experimental and theoretical approaches

The ligands 4-fluorobenzoate (4-fba), 4-chlorobenzoate (4-cba), 4-bromobenzoate (4-bba) and 4-iodobenzoate (4-iba) were chosen in order to synthesize europium(III), gadolinium(III) and terbium(III) complexes and compare the effect of halogens on their physical chemistry and luminescent properties. The homobimetallic complex [Eu(4-iba)3(H2O)(dmf)]2 crystallizes in the monoclinic P21/c space group with unit cell parameters a = 8.3987(9) Å, b = 25.314(3) Å, c = 14.1255(17) Å, and β = 105.347(2)°. FTIR spectroscopy indicates that the bidentate bridging mode of the carboxylato ligand was present in all complexes while bidentate chelate and a mixture of bidentate bridging and chelate modes were also found. According to emission spectra profiles and the Judd–Ofelt parameters the halogen of ligand molecules modifies the chemical environment symmetry around the europium(III) ion in their respective complexes. The complexes [Eu(4-fba)3(H2O)2] and [Eu(4-iba)3(H2O)2] have the highest symmetry around the europium(III) while the complexes [Eu(4-cba)3]·2H2O, [Eu(4-bba)3]·5/2H2O and [Eu(4-iba)3(H2O)(dmf)]2 have the lowest. The different halogens at the para position do not change the covalence degree of Eu–O bonds significantly, however they play a role in the ligand to metal charge transfer energies. The highest non-radiative energy transfer rates from ligand to europium(III) were found for the complexes [Eu(4-cba)3]·2H2O and [Eu(4-bba)3]·5/2H2O

A series of three isostructural 1D lanthanide coordination network based on 4,4 ',4 ''-((benzene-1,3,5-triyltris(methylene))tris(oxy))tribenzoate ligand: Synthesis, crystal structure and photophysical properties

Three 1D-coordination networks namely {[Ln(L)(DMF)(H2O)]center dot DMF}(n). represented as EuL, GdL and TbL were obtained using the synthetized 4,4',4 ''-((benzene-1,3,5-triyltris(methylene))tris(oxy))tribenzoic acid (H3L) as a ligand and lanthanide nitrate salts (Ln(NO3)(3)) (Ln = Eu-III, Gd-III or Tb-III). The reactions were carried out under solvothermal conditions using a mixture of DMF and H2O. Single crystal X-ray analyses revealed that all three compounds are isostructural crystalizing in the triclinic space group P (1) over bar. They show an interesting binodal connected one-dimensional structure, with a static crystal disorder due to the different spatial orientations of DMF molecules. The triplet state energy of the H3L ligand obtained from {[Gd(L)(DMF)(H2O)]center dot DMF}(n) lies energetically above the main emitting states of both Eu-III and Tb-III. The photophysical properties were investigated in terms of excitation, emission spectra and emission lifetime at three different temperatures. EuL and TbL exhibit characteristic emission bands of the Eu-III and Tb-III with emission lifetimes of 0.51 ms and 0.90 ms, respectively. The emission lifetime values of EuL and TbL remain practically constant in the temperature range from 77 to 300 K. Furthermore, it is mentioned a possible effect of a crystal disorder on the luminescence profile of Eu-III in EuL4942129CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP141691/2015-8não tem2014/50906-9; 2013/22127-