A novel class of luminescent polymers obtained by the sol–gel approach

Bermúdez, V. de Zea; Carlos, Luı́s D.; Duarte, Marta Cristina Teixeira; Silva, M.M; Silva, C.J.R; Smith, Michael J.; Assunção, M.; Alcácer, Luís

doi:10.1016/s0925-8388(98)00266-7

Cited by 89 publications

(44 citation statements)

References 17 publications

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“…[37] The lack of am elting peak of [BIm][TfO] in the DSC thermograms of the three electrolytes demonstrates the good compatibility existing between this PILa nd the host di-ureasil hybrid matrix environment, no matter the concentration of [BIm] [TfO].I nt he DSC curve of the d-U(2000) host hybrid matrix, the weak, ill-defined,a nd broad endotherm observed in the low-temperature range (inset of Figure 3b)i sa ssociated with the meltingo fam inor proportion of the POE crystallites present. [38] However,t he correspondingB ragg peaks expected at 2 q = 19 and 298 are not detected in the XRD pattern of d-U(2000),p robablyb ecause they are masked by the prominentbroad band at 2 q = 218.…”

Section: Resultsmentioning

confidence: 98%

“…The XRD patterns presentabroad band centered at around2q = 218 (Figure 3a), which corresponds to ordering within the siliceous domains. [38] However,t he correspondingB ragg peaks expected at 2 q = 19 and 298 are not detected in the XRD pattern of d-U(2000),p robablyb ecause they are masked by the prominentbroad band at 2 q = 218. [38] However,t he correspondingB ragg peaks expected at 2 q = 19 and 298 are not detected in the XRD pattern of d-U(2000),p robablyb ecause they are masked by the prominentbroad band at 2 q = 218.…”

Section: Introductionmentioning

confidence: 98%

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Di‐ureasil Hybrid Electrolytes Incorporating a New Proton Ionic Liquid

et al. 2016

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The protic ionic liquid (PIL) N‐butylimidazolium trifluoromethanesulfonate ([BIm][TfO]) was obtained for the first time and incorporated into a sol–gel‐derived di‐ureasil matrix with a concentration of X=5, 10, and 30 %, where X is the ratio of the mass of PIL per mass of poly(oxyethylene). Four years after their synthesis, the resulting quasi‐anhydrous electrolytes remained amorphous, homogeneous, flexible, and thermally stable below 200 °C. SEM/EDS data revealed the presence of the PIL at the surface of the xerogels with X>5 %, demonstrating that this type of morphological characterization is mandatory to avoid misleading ionic conductivity values. The highest ionic conductivity was produced in the washed sample with X=30 % (3.5×10−5 and 2.1×10−3 S cm−1 at 25 and 170 °C, respectively). The present family of electrolytes yielded higher conductivities than the N‐ethylimidazolium trifluoromethanesulfonate‐based analogues introduced earlier by our group and may thus be considered as promising candidates for applications in fuel cells.

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Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

Di‐ureasil Hybrid Electrolytes Incorporating a New Proton Ionic Liquid

et al. 2016

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“…A family of hybrids, which recently attracted interest, consists of siloxane-polyether nanometer scale composites (Figure 1), in which the organic and inorganic phases are bonded by urea bridges, thus named ureasils [27]. These transparent materials were originally synthesized to be used in photochromic devices [28] as solid electrolytes [29,30] because the covalent bonds between the polymer and the siloxane backbone hinder phase separation, preserving the stability of mechanical and thermal properties.…”

Section: Resultsmentioning

confidence: 99%

Novel Solid State Nitric Oxide Sensor Using Siloxane-Poly(Oxypropylene) (PPO)

Herculano

Brunello²,

Melo³

et al. 2013

MSA

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In this paper, a novel solid state Nitric Oxide (NO) sensor made of a spin trap (iron(II)-diethyldithiocarbamate complex, FeDETC) encapsulated in a siloxane-poly(oxypropylene) (PPO) matrix was developed. Nitric oxide (NO), a free radical molecule, has numerous roles in various physiological functions, such as the regulation of blood pressure, immune response to bacterial infection, and nervous systems. Siloxane-polyether hybrid materials, for example siloxanepoly(oxypropylene) (PPO), are easy to prepare, transparent and flexible. The combination of all these characteristics in a unique material allows it to be used in several scientific and technological areas, including human health. NO radical is trapped in FeDETC, which allows its detection by electron paramagnetic resonance (EPR). FeDETC was added while PPO was a sol, which was then left in air for gelation. The novel sensor was dived directly into a solution of NO, when the NO-FeDETC complex was formed. Our results show that the novel sensor responds to NO, with similar sensitivity as previously published sensors. PPO sensors present a strong EPR signal and a high stability, keeping its signal for 45 days. We have studied ways to accelerate the NO release from the sensor, in order to study its potential as a drug delivery system. We observed an acceleration in NO release by using a modulated magnetic field of 40 G at 100 kHz; as well as by UV irradiation. Thermal induced NO release was also tested by heating NO-FeDETC PPO up to 50˚C, with good results.

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“…The Nd 3+ ions are attractive in the area of SPEs owing to their high Lewis acidity and coordination number. Silva et al prepared SPEs from poly(oxyethylene) (POE) and europium (Eu 3+ ), Nd 3+ , and Er 3+ triflates [38,39,40]. These authors reported relatively higher ionic conductivity for the system doped with NdTrif 3 with respect to the analogue electrolytes doped with the other two lanthanide triflates [40].…”

Section: Introductionmentioning

confidence: 99%

Luminescent κ-Carrageenan-Based Electrolytes Containing Neodymium Triflate

et al. 2019

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In recent years, the synthesis of polymer electrolyte systems derived from biopolymers for the development of sustainable green electrochemical devices has attracted great attention. Here electrolytes based on the red seaweeds-derived polysaccharide κ-carrageenan (κ-Cg) doped with neodymium triflate (NdTrif3) and glycerol (Gly) were obtained by means of a simple, clean, fast, and low-cost procedure. The aim was to produce near-infrared (NIR)-emitting materials with improved thermal and mechanical properties, and enhanced ionic conductivity. Cg has a particular interest, due to the fact that it is a renewable, cost-effective natural polymer and has the ability of gelling in the presence of certain alkali- and alkaline-earth metal cations, being good candidates as host matrices for accommodating guest cations. The as-synthesised κ-Cg-based membranes are semi-crystalline, reveal essentially a homogeneous texture, and exhibit ionic conductivity values 1–2 orders of magnitude higher than those of the κ-Cg matrix. A maximum ionic conductivity was achieved for 50 wt.% Gly/κ-Cg and 20 wt.% NdTrif3/κ-Cg (1.03 × 10−4, 3.03 × 10−4, and 1.69 × 10−4 S cm−1 at 30, 60, and 97 °C, respectively). The NdTrif-based κ-Cg membranes are multi-wavelength emitters from the ultraviolet (UV)/visible to the NIR regions, due to the κ-Cg intrinsic emission and to Nd3+, 4F3/2→4I11/2-9/2.

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A novel class of luminescent polymers obtained by the sol–gel approach

Cited by 89 publications

References 17 publications

Di‐ureasil Hybrid Electrolytes Incorporating a New Proton Ionic Liquid

Di‐ureasil Hybrid Electrolytes Incorporating a New Proton Ionic Liquid

Novel Solid State Nitric Oxide Sensor Using Siloxane-Poly(Oxypropylene) (PPO)

Luminescent κ-Carrageenan-Based Electrolytes Containing Neodymium Triflate

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