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Rapid analysis of marble treatments by laser induced fluorescence
摘要： Nowadays scientific study of Cultural Heritage accompanies most of the time historical artistic evaluation and an assessment of the conservation state by humanistic experts and restorers. Several laboratory methods with high sensitivity are well established (ICP-MS, FTIR,…), and many methods for in situ rough characterization of large surface are widely diffused (thermovision, UV photography,…), in addition to instrumentation for punctual analysis to be applied also in field (XRF, colorimetry,…). However, the request for systems that can provide rapid detailed characterization on large surface in any storage conditions is still a hot topic. This is combined with the ever-increasing demand for digital material for documentation, fruition and study. Laser-based systems, and in particular Laser Induced Fluorescence (LIF), Laser Induced Breakdown Spectroscopy and Raman spectroscopy, due to the characteristics of these sources and the detectors to which they can be coupled, respond well to these needs. The TECFIS-DIM (Diagnostic and Metrology) Laboratory of the ENEA center of Frascati (Rome, Italy) in the last decade has put an effort to develop more and more compact and efficient laser systems for in situ material characterization on cultural heritage surfaces. Here two prototypal LIF systems have been used to characterize marble surfaces treated with ancient and modern materials and a rapid recognition and mapping method has been developed and tested thanks to the individuation of discriminant spectral features. Results are reported on test samples created in lab with known substances and in situ on real artworks.
关键词： Patinas,Marble,Polymers,Laser spectroscopies,Laser induced fluorescence (LIF)
更新于2025-09-23 15:19:57
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Novel conductive multi-walled polymeric nanotubes of poly(diazoaminobenzene) for single-layer polymer solar cell
摘要： Novel conductive multi-walled polymeric nanotubes (MWPNTs) of poly(diazoaminobenzene) (PDAAB) were synthesized using diazoaminobenzene monomer for the first time in this report. The synthesis followed a one-pot, cost-effective, green and template-free procedure, in which aniline was used as initiator with 87% yield at room temperature. PDAAB was characterized with spectroscopic and microscopic methods such as Fourier-transform infrared (FTIR), UV-vis, X-ray diffractometry (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM) as well as cyclic voltammetry (CV) and conductivity measurements. In addition, MWPNTs were used in the design of a novel single-layer polymer solar cell. PDAAB was sandwiched between TiO2 nanoparticle-modified fluorine-doped tin oxide (FTO) electrode and an aluminum electrode (FTO-TiO2│PDAAB│Al), as anode and cathode, respectively. Finally, various physical characteristics of the single-layer polymer solar cell were determined under simulated solar irradiation. Our proof-of-concept study demonstrated that MWPNTs provided a promising platform to develop polymer-based solar energy conversion and storage systems.
关键词： multi-walled polymeric nanotube,aniline,conductive polymers,Poly(diazoaminobenzene),solar cell
更新于2025-09-23 15:19:57
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Design of novel thiazolothiazole-containing conjugated polymers for organic solar cells and modules
摘要： One of the major challenges in the field of organic photovoltaics is associated with high-throughput manufacturing of efficient and stable organic solar cells. Practical realization of technologies for production of large-area organic solar cells requires the development of novel materials with a defined combination of properties ensuring sufficient reliability and scalability of the process in addition to good efficiency and operation stability of the devices. In this work, we designed two novel polymers comprising thiazolothiazole units and investigated their performance as absorber materials for organic solar cells and modules. Optimized small-area solar cells based on P1/[70]PCBM ([6,6]-phenyl-C71-butyric acid methyl ester) blends exhibited promising power conversion efficiency (PCE) of 7.5%, while larger area modules fabricated using slot die coating showed encouraging PCE of 4.2%. Additionally, the fabricated devices showed promising outdoor stability maintaining 60–70% of the initial efficiency after 20 sun days being exposed to natural sunlight at the Negev desert. The obtained results feature the designed polymer P1 as a promising absorber material for a large-scale production of organic solar cells under ambient conditions.
关键词： Thiazolothiazole,Conjugated polymers,Photovoltaic modules,Organic solar cells,Slot-die coating
更新于2025-09-23 15:19:57
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Thermoplasmonica??Activated Hydrogel Based Dynamic Light Attenuator
摘要： This work describes the morphological, optical, and thermo-optical properties of a temperature-sensitive hydrogel poly(N-isopropylacrylamide-co-N-isopropylmethacrylamide) [P(NIPAm-co-NIPMAm]) film containing a specific amount of gold nanorods (GNRs). The light-induced thermoplasmonic heating of GNRs is used to control the optical scattering of an initially transparent hydrogel film. A hydrated P(NIPAm-co-NIPMAm) film is optically clear at room temperature. When heated to temperatures over 37 °C via light irradiation with a resonant source (λ = 810 nm) to the GNRs, a reversible phase transition from a swollen hydrated state to a shrunken dehydrated state occurs. This phenomenon causes a drastic and reversible change in the optical transparency from a clear to an opaque state. A significant red shift (≈30 nm) of the longitudinal band can also be seen due to an increased average refractive index surrounding the GNRs. This change is in agreement with an ad hoc theoretical model which uses a modified Gans theory for ellipsoidal nanoparticles. Morphological analysis of the composite film shows the presence of well-isolated and randomly dispersed GNRs. Thermo-optical experiments demonstrate an all-optically controlled light attenuator (65% contrast ratio) which can be easily integrated in several modern optical applications such as smart windows and light-responsive optical attenuators.
关键词： gold nanorods,active plasmonics,optical attenuators,polymers,optical transparency,hydrogels,plasmonic nanoparticles
更新于2025-09-23 15:19:57
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Synthesis and Characterization of Wide-Bandgap Conjugated Polymers Consisting of Same Electron Donor and Different Electron-Deficient Units and Their Application for Nonfullerene Polymer Solar Cells
摘要： Substantial development has been made in nonfullerene small molecule acceptors (NFSMAs) that has resulted in a significant increase in the power conversion efficiency (PCE) of nonfullerene-based polymer solar cells (PSCs). In order to achieve better compatibility with narrow-bandgap nonfullerene small molecule acceptors, it is important to design the conjugated polymers with a wide bandgap that has suitable molecular orbital energy levels. Here two donor–acceptor (D–A)-conjugated copolymers are designed and synthesized with the same thienyl-substituted benzodithiophene and different acceptors, i.e., poly{(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl)-alt-(1,3-bis(2-octyldodecyl)-1,3-dihydro-2H-dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2-d]imidazol-2-one-5,8-diyl)} (DTBIA, P1) and poly{(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl)-alt-(2-(5-(3-octyltridecyl)thiophen-2-yl)dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2-d]thiazole-5,8-diyl)} (TDTBTA, P2) (and their optical and electrochemical properties are investigated). Both P1 and P2 exhibit similar deeper highest occupied molecular orbital energy level and different lowest unoccupied molecular orbital energy level. Both the copolymers have complementary absorption with a well-known nonfullerene acceptor ITIC-F. When blended with a narrow-bandgap acceptor ITIC-F, the PSCs based on P1 show a power conversion efficiency of 11.18% with a large open-circuit voltage of 0.96 V, a Jsc of 16.89 mA cm?2, and a fill factor (FF) of 0.69, which is larger than that for P2 counterpart (PCE = 9.32%, Jsc = 15.88 mA cm?2, Voc = 0.91 V, and FF = 0.645). Moreover, the energy losses for the PSCs based on P1 and P2 are 0.54 and 0.59 eV, respectively. Compared to P2, the P1-based PSCs show high values of incident photon to current conversion efficiency (IPCE) in the shorter-wavelength region (absorption of donor copolymer), more balanced hole and electron mobilities, and favorable phase separation with compact π–π stacking distance.
关键词： solvent vapor annealing,polymer solar cells,nonfullerene acceptors,wide-bandgap polymers
更新于2025-09-23 15:19:57
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Lasera??Triggered Writing and Biofunctionalization of Thiola??Ene Networks
摘要： The light responsivity of ortho-nitrobenzyl esters (o-NBE) is exploited to inscribe μ-scale 2.5D patterns in thiol-ene networks by direct laser writing. For this purpose, a multifunctional thiol and a photosensitive alkene with an o-NBE chromophore are cured upon visible light exposure without inducing a premature photocleavage of the o-NBE links. Once the network is formed, a laser beam source with a wavelength of 375 nm is used for selectively inducing the photocleavage reaction of the o-NBE groups. Positive tone patterns are directly inscribed onto the sample surface without the requirement of a subsequent development step (removing soluble species in an appropriate organic solvent). Along with the realization of dry-developable micropatterns, the chemical surface composition of the exposed areas can be conveniently adjusted since different domains with a tailored content of carboxylic groups are obtained simply by modulating the laser energy dose. In a following step, those are activated and exploited as anchor points for attaching an Alexa-546 conjugated Protein A. Thus, the laser writable thiol-ene networks do not only provide a convenient method for the fabrication of positive tone patterns but also open future prospectives for a wide range of biosensing applications.
关键词： thiol-ene polymers,phototriggered functional groups,biofunctionalization,micropatterning,laser writing
更新于2025-09-23 15:19:57
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Dithiazolylthienothiophene Bisimide-Based ??-Conjugated Polymers: Improved Synthesis and Application to Organic Photovoltaics as P-Type Semiconductor
摘要： Dithiazolylthienothiophene bisimide (TzBI) is a promising building unit for donor-acceptor π-conjugated polymers due to its strong electron-deficiency and high coplanarity. We previously reported a TzBI-based π-conjugated polymer functioned as n-type semiconductor in organic photovoltaic cells. However, a critical subject was that the molecular weight of the polymer was not sufficiently high. It is also important to investigate the possibility of TzBI-based polymers as the p-type semiconductor. In this study, we show that a new synthetic approach gave a new TzBI-based polymer with an improved molecular weight relative to the previously reported polymer. Further, having a co-building unit with a more electron-rich nature, the polymer functioned as p-type semiconductor in organic photovoltaic cells when the PC61BM was used as n-type material. This study shows that TzBI is a versatile building unit for π-conjugated polymers that can be used in organic electronic devices.
关键词： Imide,π-Conjugated polymers,Organic photovoltaics
更新于2025-09-23 15:19:57
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Trap-Assisted Triplet Emission in Ladder-Polymer-Based Light-Emitting Diodes
摘要： The charge transport and recombination in light-emitting diodes (LEDs) based on a methyl-substituted poly(p-phenylene) ladder polymer (Me-LPPP) are investigated. The transport is characterized by a high room-temperature hole mobility of 2 × 10?8 m2 V?1 s?1 combined with anomalously strong electron trapping. Their electroluminescence (EL) spectrum is characterized by a blue singlet emission, a broad green featureless peak, and a yellow-orange triplet emission. The voltage dependence of the EL spectrum and negative contribution to the capacitance indicate that the triplet-emission is of trap-assisted nature, consistent with the strong electron trapping. Consequently, the color purity of the blue emissive Me-LPPP polymer LEDs can be strongly improved using trap dilution.
关键词： conjugated polymers,charge transport,light-emitting diodes
更新于2025-09-23 15:19:57
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Coupled Electrical Conduction in Coordination Polymers: From Electrons/Ions to Mixed Charge Carriers
摘要： The coupled transport of ions and electrons is of great potential for next-generation sensors, energy storage and conversion devices, optoelectronics, etc. Coordination polymers (CPs) intrinsically have both transport pathways for electrons and ions, however, the practical conductivities are usually low. In recent years, significant advances have been made in electronic or ionic conductive coordination polymers, which also results in progress in mixed ionic-electronic conductive coordination polymers. Here we start from electronic and ionic conductive CPs to mixed ionic-electronic conductive CPs. Recent advances in the design of mixed ionic-electronic conductive CPs are summarized. In addition, devices based on mixed conduction are selected.
关键词： metal-organic frameworks,coordination polymers,ionic,conductivity,electronic
更新于2025-09-23 15:19:57
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Delocalization boosts charge separation in organic solar cells
摘要： Organic solar cells (OSCs) utilizing π-conjugated polymers have attracted widespread interest over the past three decades because of their potential advantages, including low weight, thin film flexibility, and low-cost manufacturing. However, their power conversion efficiency (PCE) has been far below that of inorganic analogs. Geminate recombination of charge transfer excitons is a major loss process in OSCs. This paper reviews our recent progress in using transient absorption spectroscopy to understand geminate recombination in bulk heterojunction OSCs, including the impact of polymer crystallinity on charge generation and dissociation mechanisms in nonfullerene acceptor-based OSCs. The first example of a high PCE with a small photon energy loss is also presented. The importance of delocalization of the charge wave function to suppress geminate recombination is highlighted by this focus review.
关键词： Polymer crystallinity,Power conversion efficiency,Organic solar cells,Transient absorption spectroscopy,Dissociation mechanisms,Photon energy loss,π-conjugated polymers,Charge generation,Nonfullerene acceptor,Geminate recombination
更新于2025-09-23 15:19:57