1,721,036 research outputs found
Nanocarta di cellulosa: proprietà e prospettive
No full textIl rinnovato interesse nei confronti della cellulosa affonda le sue basi nella conoscenza
approfondita oggi a disposizione sulla sua struttura cristallina e sulle sue proprietà.
I film di cellulosa nanocristallina sono trasparenti e flessibili e prendono il nome di nanocarta.
Essi potrebbero sostituire altri film plastici in molte applicazioni.The renewed interest towards cellulose comes
from the deeper knowledge that is nowadays available
about its crystalline structure and its properties.
Films of nanocrystalline cellulose are transparent
and flexible and are named nanopaper. They
could replace other plastic materials films in many
applications
Recent Advances on Renewable and Biodegradable Cellulose Nanopaper Substrates for Transparent Light-Harvesting Devices: Interaction with Humid Environment
Full text linkCellulose nanopaper (CNP) has attracted much interest during the last decade as a new fascinating renewable and biodegradable substrate for printed electronics and solar cells. Its outstanding optical and mechanical properties make CNP the ideal substrate for the preparation of photovoltaic devices, since its high transparency and haze favour the absorption of light from the active layer of the solar cell. However, some advances need to be done in the direction of increasing CNP stability in humid environment without compromising its remarkable advantages. This review critically points at these aspects, presenting an overview of state-of-art solutions to enhance nanopaper stability in a humid environment
Interplay of Circularly Polarized Light with Molecular and Structural Chirality: Chiral Lanthanide Complexes and Cellulose Nanocrystals
Full text linkThe interaction of circularly polarized (CP) light with chiral matter at different scales opens several possibilities of light manipulation in photonic and electronic devices. Here it is shown that in a multilayer architecture, it is possible to take advantage of the polarization-selective reflection of the nematic arrangement of cellulose nanocrystals and the strong intrinsic CP luminescence (CPL) of the various bands of chiral Eu complexes. In this way, both the intrinsic CPL and total emission of the complex are modified depending on the enantiomer applied and on the detection geometry. This concept may apply for polarization control in electronic and photonic devices and polarized optical cavities
Molecular and Supramolecular Architectures of Organic Semiconductors for Field Effect Transistor Devices and Sensors: a Synthetic Chemical Perspective
No full textOrganic field-effect transistors (OFETs) are key devices in organic electronics, and their performances largely depend on molecular structure and solid-state organization of the π-conjugated compounds used as semiconductors. This microreview reports several examples of materials for OFET devices and sensors, which have been selected to highlight the basic criteria of molecular design together with the synthetic logic driving the development of organic semiconductors. Versatile synthetic methodologies enable to optimize properties by tailoring molecular structures and functionalization, thus playing a key role in the progress of OFET technology, and more in general of organic electronics, which is emphasized in the discussion
Synthesis of S-acetyl oligoarylenedithiols via Suzuki-Miyaura cross-coupling
No full textOligoarylenes with three or four aromatic rings, bearing two
S-acetylated mercaptomethyl groups in 1,3 position on one
end of the polyaromatic system and presenting various
functionalities on the other terminal ring, have been synthesized
by the Suzuki-Miyaura cross-coupling reaction. The
use of palladium complexes with a Buchwald’s phosphine
as ligand allowed us to perform this coupling reaction also
in the presence of benzylic S-acetyl-protected functionalities
on the aromatic halide. The obtained oligoarylenes are
potential novel candidates for the generation of self-assembling
monolayers on metal substrates
Synthetic Routes to Thiol-Functionalized Organic Semiconductors for Molecular and Organic Electronics
No full textOver the few last decades, the potential of using thiol functionalities to induce the self-assembly of various kinds of molecules on metal surfaces has been widely demonstrated. In particular, π-conjugated molecules can undergo self-assembly on metallic surfaces to create electroactive supramolecular layers, which have found important applications in organic and molecular electronics. For this reason, the synthesis of thiol-functionalized conjugated molecules has been the object of extensive research and many routes have been developed for their synthesis. This Focus Review provides an overview of the state-of-the-art methods for the syntheses of organic semiconductors that are decorated with pendant thiol groups for applications in self-assembly and molecular and organic electronics. Particular attention is given to synthetic strategies based on organometallic cross-coupling reactions for the preparation of compounds with extended conjugation
PHENYLENE-THIOPHENE POLYMERS AND OLIGOMERS FOR ORGANIC ELECTRONICS: SYNTHESIS, PROPERTIES AND APPLICATION IN DEVICES
No full textSeveral organometallic methods are used to synthesize pi-conjugated molecules and polymers with alternating thiophene-dialkoxyphenylene units in the conjugated backbone. Here we describe our approaches to the synthesis of materials based on the dialkoxyphenylenethienylene structural motif via palladium catalyzed cross-coupling reactions of organomagnesium or organoboron reagents with aryl halides. The properties of the resulting compounds and their applications in (opto)electronic devices (organic field effect transistors, resistive gas sensors, field effect chiral sensors, photoelectrochemical cells and bulk-heterojunction solar cells) are also discussed, highlighting the role of the synthetic logic in the design of multifunctional organic materials
Theoretical studies on the conformation and electronic distribution of two thiophene-phenyl/benzothiadiazole pi-conjugated copolymers
No full textSynthesis of D-Glucose and L-Phenylalanine Substituted Phenylene-Thiophene Oligomers
No full textPhenylene-thiophene oligomers bearing peracetylated beta-D-glucose or N-BOC-L-phenylalanine as chiral substituents were synthesized in good yields by a versatile protocol based on the Suzuki-Miyaura cross-coupling reaction. Aryl iodides bearing the chiral biomolecules as substituents efficiently reacted with pinacol boronates of bi- or terthiophenes leading to the bio-functionalized oligomers in good yields
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