Search results for "Organic polymer"
showing 10 items of 21 documents
Theoretical study of the effect of substituent and backbone conformation on the electronic properties of symmetrically substituted poly(di‐n‐alkylsil…
1994
We present the results of ab initio 3‐21G∗ geometry optimizations and valence effective Hamiltonian (VEH) band structure calculations aimed at determining the evolution of the geometric and electronic (ionization potential, electron affinities, and band gaps) properties of all‐trans poly(dimethylsilane), poly(diethylsilane), poly(di‐n‐propylsilane), and poly(di‐n‐butylsilane) when increasing the size of the alkyl group. In the latter polymer, we have also studied the 7/3 conformation, in order to analyze the effect of the backbone conformation on the geometric and electronic structure. The VEH ionization potentials of all‐trans poly(di‐n‐alkylsilanes) are almost equal, and as experimental p…
Generation of white LED light by frequency downconversion using a perylene-based dye
2012
A high efficiency white light emitting diode (LED) was fabricated by generation of frequency down-conversion from a GaN/InGaN blue LED. In place of conventional inorganic phosphors, a perylene-based dye was used for colour conversion. The resulting hybrid structure is analysed by focusing on the visual performance of the realised LEDs employing the most relevant photometric parameters of a light source. Preparation of the organic polymer is described as well. The thermal stability of the dye was investigated and a simple structure which avoids colour degradation is proposed.
Incorporation of metal-organic framework amino-modified MIL-101 into glycidyl methacrylate monoliths for nano LC separation.
2018
Metal-organic frameworks consisting of amino-modified MIL-101(M: Cr, Al, and Fe) crystals have been synthesized and subsequently incorporated to glycidyl methacrylate monoliths to develop novel stationary phases for nano-liquid chromatography. Two incorporation approaches of these materials in monoliths were explored. The metal-organic framework materials were firstly attached to the pore surface through reaction of epoxy groups present in the parent glycidyl methacrylate-based monolith. Alternatively, NH2 -MIL-101(M) were admixed in the polymerization mixture. Using short time UV-initiated polymerization, monolithic beds with homogenously dispersed metal-organic frameworks were obtained. T…
Low angle bending detection semi-transparent piezoresistive sensor
2022
We designed, fabricated, and validated a piezoresistive bending sensor, a fundamental component of wearable electronic devices for monitoring human motion. The most diffused opaque carbon-based resistance flex sensors suffer from low detection for small bending angles. The sensor we here present is based on a semi-transparent active material (fulleropyrrolidine bisadducts polymer) and has the remarkable advantage of good electrical properties for low bending angles. The fabrication steps are effective since a pre-patterned ITO/PET surface is functionalized by chronoamperometric deposition, and the silver electrical contacts are inkjet printed. We propose a fitting function of the measured t…
Silicateins - A Novel Paradigm in Bioinorganic Chemistry: Enzymatic Synthesis of Inorganic Polymeric Silica
2013
The inorganic matrix of the siliceous skeletal elements of sponges, that is, spicules, is formed of amorphous biosilica. Until a decade ago, it remained unclear how the hard biosilica monoliths of the spicules are formed in sponges that live in a silica-poor (<50 mu m) aquatic environment. The following two discoveries caused a paradigm shift and allowed an elucidation of the processes underlying spicule formation; first the discovery that in the spicules only one major protein, silicatein, exists and second, that this protein displays a bio-catalytical, enzymatic function. These findings caused a paradigm shift, since silicatein is the first enzyme that catalyzes the formation of an inorga…
A two-dimensional magnetic architecture with bridging polynitrile and 2,2′-bipyrimidine ligands
2004
cited By 7; International audience; A new polymeric, two-dimensional compound [Co2(bpym)(dcne) 4 (H2O)2] (1) (dcne = [(CN)2CC(O) OEt)]- = 2,2-dicyano-1-ethoxyethenolate anion and bpym = 2,2'-bipyrimidine) has been synthesized and characterized by X-ray crystallography. The structure is monoclinic space group P21/a and consists of two-dimensional networks of octahedrally coordinated Co(II) ions, bridged by bis-bidentate 2,2'-bipyrimidine and μ2-dcne anions. Magnetic measurements revealed a broad maximum in the xm vs T plot at 20 K which is characteristic of antiferromagnetic exchange between the high spin cobalt(II) centres. © EDP Sciences.
Synthesis of oligomers and polymers doped with porphyrins for solar energy conversion
2017
The aim of this thesis was to elaborate new electron donor materials for organic solarcells. This emerging photovoltaic technology is rapidly expanding, and has yet already reached the limit for its large-scale commercialization. The low manufacturing cost of organic photovoltaic devices make then competitive face to well-established inorganic technologies. Their biggest advantage is their weight and their mechanical properties which make them flexible. They should play a key role in future as a complement to classic solar cells, with their use in specific applications. We developed polymers by using different chomophores, well-known for their interesting photophysical properties: the porph…
Surface coatings based on polysilsesquioxanes: Grafting-from approach starting from organic polymers
2009
AbstractPoly(methylsilsesquioxane) (PMSSQ) based hybrid materials are promising candidates to produce substrate-independent stable and adherent surface coatings. Usually these materials are synthesized by controlled radical polymerization from inorganic precursors. The presented synthetic pathway in here demonstrates how to graft PMSSQ networks from an endgroup-functionalized organic polymer and thus enlarges the range of accessible inorganic/organic hybrid coating materials.
Electrical Behaviour of Heterobimetallic [MM′(EtCS2)4] (MM′=NiPd, NiPt, PdPt) and MM′X-Chain Polymers [PtM(EtCS2)4I] (M=Ni, Pd)
2012
Herein, we report the isolation of new heterobimetallic complexes [Ni0.6Pd1.4ACHTUNGTRENUNG(EtCS2)4] (1), [NiPtACHTUNGTRENUNG(EtCS2)4] (2) and [Pd0.4Pt1.6ACHTUNGTRENUNG(EtCS2)4] (3), which were constructed by using transmetallation procedures. Subsequent oxidation with iodine furnished the MM'X monodimensional chains [Ni0.6Pt1.4ACHTUNGTRENUNG(EtCS2)4I] (4) and [Ni0.1Pd0.3Pt1.6ACHTUNGTRENUNG(EtCS2)4I] (5). The physical properties of these systems were investigated and the chain structures 4 and 5 were found to be reminiscent of the parent [Pt2ACHTUNGTRENUNG(EtCS2)4I] species. However, they were more sensitively dependent on the localised nature of the charge on the Ni ion, which caused spont…