In this work, we exploit Langmuir adsorption isotherms to compare the performance of different materials (adsorbents) in removing organic contaminants (adsorbates) from water. The removal efficiency observed reaches an intrinsic limit at low concentrations. We also demonstrate quantitatively how multi-step adsorption processes achieve better purification efficiency than single-step adsorption performed using much smaller amounts of adsorbent material. We demonstrate how such performance is strongly affected by adsorbent concentration. Only the use of both the parameters obtained from Langmuir adsorption isotherm (Q(m) and K-L) modelling allows one to compare materials tested under different experimental conditions by different groups, whereas most published reviews focus only on Q(m) which is rather limited for comparing the performance of different materials studied under different conditions. Finally, we present some guidelines for data reporting in future work and reviews.

Organic field-effect transistors (OFETs) are considered almost purely interfacial devices with charge current mainly confined in the first two semiconducting layers in contact with the dielectric with no active role of the film thickness exceeding six to eight monolayers (MLs). By a combined electronic, morphological, structural, and theoretical investigation, it is demonstrated that the charge mobility and source-drain current in 2,20-(2,20-bithiophene-5,50-diyl)bis(5-butyl-5H-thieno[2,3-c]pyrrole-4,6)-dione (NT4N) organic transistors directly correlate with the out-of-plane domain size and crystallite orientation in the vertical direction, well beyond the dielectric interfacial layers. Polycrystalline films with thickness as high as 75 nm (approximate to 30 MLs) and 3D molecular architecture provide the best electrical and optoelectronic OFET characteristics, highlighting that the molecular orientational order in the bulk of the film is the key-enabling factor for optimum device performance. X-ray scattering analysis and multiscale simulations reveal the functional correlation between the thickness-dependent molecular packing, electron mobility, and vertical charge distribution. These results call for a broader view of the fundamental mechanisms that govern field-effect charge transport in OFETs beyond the interfacial 2D paradigm and demonstrate the unexpected role of the out-of-plane domain size and crystallite orientation in polycrystalline films to achieve optimum electronic and optoelectronic properties in organic transistors

We herein address the problem of polymorph selection by introducing a general and straightforward concept based on their ordering. We demonstrated the concept by the ordered patterning of four compounds capable of forming different polymorphs when deposited on technologically relevant surfaces. Our approach exploits the fact that, when the growth of a crystalline material is confined within sufficiently small cavities, only one of the possible polymorphs is generated. We verify our method by utilizing several model compounds to fabricate micrometric "logic patterns" in which each of the printed pixels is easily identifiable as comprising only one polymorph and can be individually accessed for further operations.

Polysulfone-graphene oxide hollow fiber membranes (PSU-GO HFs) with simultaneous adsorption and ultrafiltration capabilities are herein described and proposed for enhanced and simplified Point-of-Use (POU) drinking water purification. The PSU-GO HFs were prepared by phase inversion extrusion by a customized semi-industrial plant and their morphology, surface properties, and porosity were investigated by combined Scanning Electron Microscopy (SEM), contact angle and Raman confocal microscopy, in relation to different GO:PSU ratios (1-5% w/w GO vs PSU) and to the final adsorption-ultrafiltration properties. Filtration modules of PSU-GO HFs of filtering surface (FS) in the range 0,015-0,28 m showed same ultrafiltration capability of PSU-HF standard filters. Synergic adsorption properties were demonstrated by studying the adsorption maximum capacity of ciprofloxacin antibiotic (CIPRO) vs GO ratio in dead end in-out configuration, the standard configuration used for PSU HFs commercial modules. Loading of 3,5% GO vs PSU was selected as case study, representing the best compromise between performance and GO nanofiller amount. Heavy metals (Pb, Cu and Cr(III)) and polyfluoroalkyl substances (PFAS) removal capabilities from tap water were competitive and in some cases outperformed Granular Activated Carbon (GAC), the standard industrial sorbent. Ciprofloxacin removal from tap water was also under real operational conditions. Moreover, release of GO from working PSU-GO modules was excluded by Surface Enhanced Raman Spectroscopy (SERS) analysis of treated water having the state-of-the-art limit of quantification of 0.1 ?g/L for GO nanosheets

Graphene nanosheets have outstanding adsorption efficiency toward organic molecules but the potential as sorbent for water purification is strongly limited by the tedious recovery of the nanosheets after the treatment, which can cause secondary contaminations. Here, we demonstrate that graphene oxide (GO) and reduced GO (rGO) nanosheets aggregation in tap water, enabling their separation by dead-end microfiltration (MF) on commercial polymeric hollow fiber modules. No evidence of GO/rGO contamination was found in microfiltered water and chemical potability of treated water was confirmed by standard protocols. Moreover, GO/rGO can be recovered (by inverting the filtration modality from IN-OUT to OUT-IN), washed and reused, this allowing the regeneration and reuse of both graphene nanosheets and the filtration module. The procedure (called here GO + MF) was optimized on tap water spiked with ofloxacin (OFLOX) or methylene blue (MB), as reference. The optimized procedure was then applied both with GO and rGO to the removal of a mixture of perfluoroalkyl substances (PFASs) from tap water at ?g/L levels, the highest concentration found in water resources abstracted for water consumption. We demonstrate that rGO + MF procedure allows to remove 138 ?g/g of total PFASs in only 30 min, i.e. an efficiency 3-5 times higher than granular activated carbon (43 ?g/g) used in real potabilization plants for PFASs removal.

Defect-rich graphene oxide (dGO) was used as sorbent for organic contaminants of emerging concern in tap water, including drugs and dyes, and the performance compared to those of lower-defects graphene types. The role of holes and carbonyl- carboxylic groups on graphene nanosheets surface on the adsorption mechanism and efficiency was investigated. dGO showed enhanced adsorption capacity toward two fluoroquinolone antibiotics (ofloxacin, OFLOX, and ciprofloxacin, CIPRO) in tap water with a maximum capacity of 650 mg/g, compared to 204 mg/g for Hummers derived commercial GO (hGO) and 125 mg/g for less defected Brodie derived GO (bGO) for OFLOX. The role of defects on the selective adsorption of OFLOX was also modelled by MD simulations, highlighting a mechanism mainly driven by the shape complementarity between the graphene holes and the molecules. Adsorption isotherms revealed different adsorption model for dGO, with a Langmuir fitting for dGO and BET fitting for all the other investigated samples. The maximum adsorption capacity of dGO for OFLOX was about six times higher than that of Granular Activated Carbon (95 mg/g), the industrial adsorption standard technology. Finally, it was also demonstrated that dGO can be recovered from treated water by ultrafiltration, this preventing secondary contamination risks and enabling safe use of graphene nanosheets for water purification.

Microwave (MW) accelerated synthesis combined with microfiltration (MF) on commercial hollow fiber modules enables fast and scalable preparation of highly pure modified graphene oxide nanosheets. The MW-MF procedure is demonstrated on polyethylenimine (PEI) modified GO, and the so-obtained GOPEI is used for simultaneous removal of arsenic and lead from water.

Extraction of proteins from blood biological fluids requires the removal of large aggregates or cells by membrane filtration. However, conventional filters, based on simple size exclusion, do not allow to remove small molecules such as antibiotics. Here, we demonstrate that a graphene oxide (GO) layer can be firmly immobilized either inside or outside polyethersulfone-polyvinylpirrolidinone hollow fibers (PES) modules and that the resulting core-shell structure inherits the microfiltration ability of PES and the adsorption selectivity of GO. GO nanosheets were deposited on fiber surface by filtration of a GO suspension through a PES cartridge (cut-off 0.1-0.2 ?m), then fixed on it by thermal annealing at 80°C, rendering them insoluble. The filtration cut-off, retention selectivity and efficiency of the resulting inner and outer modified hollow fibers (HF-GO) were tested by performing filtration on water spiked with bovin serum albumin (BSA, 66KDa, ?15 nm sized), monodisperse polystyrene nanoparticles (52 nm and 303 nm sized), water contaminated with two quinolonic antibiotics (ciprofloxacin and ofloxacin) and rhodamine B (RhB). These tests showed that microfiltration capability of PES was retained by HFGO, in addition the GO coating can capture the molecular contaminants while letting through BSA and smaller Polystyrene nanoparticles. Combined XRD, molecular modelling and adsorption experiments show the separation mechanism does not rely only on a physical size exclusion, but it involves intercalation of solute molecules between GO layers.

Understanding of polymorphism of organic semiconducting materials is the key to structural control of their electrical and mechanical properties. Motivated by the ambipolar n-type charge transport and electroluminescence of thienopyrrolyldione end-capped oligothiophenes, here we studied the propensity of one representative to crystallize as different polymorphs which display distinctly different mechanically properties. The crystal structures of the two polymorphs (denoted "?" and "?") of the material, 2,2'-(2,2'-thiophene-5,5'-diyl)bis(5-butyl-5H-thieno[2,3-c]pyrrole-4,6)-dione (C4-NT3N), were determined. In the ? phase, the molecules interact strongly by ?-stacking, forming columns which are bonded via C-H - O and chalcogen bonds, and this packing is consistent with the elastic behavior observed with the crystals. Instead, the ? phase has the molecules aligned along their core forming layers. While the molecules interact strongly within the layers, they are practically unbound between the layers. The presence of slip planes in this form explains the plastic deformation induced by applying a force perpendicular to the (001). The thermal behavior and the enantiotropic relationship of the polymorphs are reported.

Due to water depletion and increasing level of pollution from standard and emerging contaminants, the development of more efficient purification materials and technology for drinking water treatment is a crucial challenge to be addressed in the near future. Graphene oxide (GO) has been pointed as one of the most promising materials to build structure and devices for new adsorbents and filtration systems. Here, we analyzed two types of GO doped 3D chitosan-gelatin aerogels with GO sheets embedded in the bulk or deposited on the surface. Through combined structural characterization and adsorption tests on selected proxies of drinking water micropollutants, we compared both GO-embedded and GO-coated materials and established the best architecture for achieving enhanced removal efficiency toward contaminants in water. To evaluate the best configuration, we studied the adsorption capacity of both systems on two organic molecules (i.e., fluoroquinolonic antibiotics ofloxacin and ciprofloxacin) and a heavy metal (lead Pb2+) of great environmental relevance and with already proved high affinity for GO. The Pb monolayer maximum adsorption capacity q(max) was 11.1 mg/g for embedded GO aerogels and 1.5 mg/g in coated GO-ones. Only minor differences were found for organic contaminants between coating and embedding approaches with an adsorption capacity of 5-8 mg/g and no adsorption was found for chitosan-gelatin control aerogels without GO. Finally, potential antimicrobial effects were found particularly for the GO-coated aerogels materials, thus corroborating the multifunctionality of the newly developed porous structures. (C) 2020 Elsevier Ltd. All rights reserved.

The fascinating combination of light-emitting characteristics and electrical amplification identifies organic light-emitting transistors (OLETs) as key enabling devices for a wide variety of applications, ranging from displays to sensors. Pursuing a dual functionality in a single-layer architecture is either the major strength and the major challenge of this technology. Limitations mainly arise from the poor availability of organic semiconductors able to ensure good ambipolar behavior in charge transport together with an efficient light-emission in the solid state. In the present perspective, we report on the new class of thienoimide-ended oligothiophenes as molecular compounds simultaneously endowed with a good field-effect mobility for holes and electrons, good processability, self-assembly capability into nanostructures and remarkable properties of photo- and electroluminescence in solid state. The versatile chemical tuning of the molecular structure and the fine use of both solution-processed and physical deposition techniques in the realization of nanostructured thin-films are the major tools for controlling the packing of molecules and their intermolecular interactions at the solid state. Indeed, the inherent polymorphism of this class of compounds is directly correlated to their electrical and optoelectronic properties as active materials in multifunctional devices. Considering the field-effect transistor as a benchmark device platform, here we propose the extended family of thienoimide-ended oligothiophenes as a case study in virtue of i) the solid and throughout correlation of the molecular structure and solid-state organization with the figures of merit in transistor-based devices, and ii) the possibility of engineering highly-integrated planar organic optoelectronic devices with multiple functionalities for the investigation of photophysical and charge transport processes in organic compounds and, ultimately, the demonstration of real-setting applications of OLET technology.

The availability of clean, pure water is a major challenge for the future of our society. 2-Dimensional nanosheets of GO seem promising as nanoporous adsorbent or filters for water purification; however, their processing in macroscopic filters is challenging, and their cost vs. standard polymer filters is too high. Here, we describe a novel approach to combine graphene oxide (GO) sheets with commercial polysulfone (PSU) membranes for improved removal of organic contaminants from water. The adsorption physics of contaminants on the PSU-GO composite follows Langmuir and Brunauer-Emmett-Teller (BET) models, with partial swelling and intercalation of molecules in between the GO layers. Such a mechanism, well-known in layered clays, has not been reported previously for graphene or GO. Our approach requires minimal amounts of GO, deposited directly on the surface of the polymer, followed by stabilization using microwaves or heat. The purification efficiency of the PSU-GO composites is significantly improved vs. benchmark commercial PSU, as demonstrated by the removal of two model contaminants, rhodamine B and ofloxacin. The excellent stability of the composite is confirmed by extensive (100 hours) filtration tests in commercial water cartridges.

The cover feature shows how polysulfone hollow fibers can be used as a versatile platform for the adsorption of perylene-based dyes by means of a wet coating procedure. The immobilized dyes can then react with amino-functionalized small molecules. The covalent binding process occurring on the fiber surface has been studied by means of fluorescence spectral and lifetime changes. This simple approach has potential applications in biomedical sensing. More details are given in the Full Paper by I. Manet, M. Melucci, and co-workers (DOI: 10.1002/cplu.201800681.

Water purification technologies possibly based on eco-sustainable, low cost, and multifunctional materials are being intensively pursued to resolve the current water scarcity and pollution. In this scenario, polysulfone hollow porous granules (PS-HPGs) prepared from scraps of the industrial production of polysulfone hollow fiber membranes were recently introduced as adsorbents and filtration materials for water and air treatment. Here, we report the functionalization of PS-HPGs with polydopamine (PD) nanoparticles for the preparation of a new versatile and efficient adsorbent material, namely, PSPD-HPGs. The in situ growth of PD under mild alkaline oxidative polymerization allowed us to stably graft PD on polysulfone granules. Enhanced removal efficiency of ofloxacin, an antibiotic drug, with an improvement up to 70% with respect to the pristine PS-HPGs, and removal of Zn(II) and Ni(II) were also observed after PD modification. Remarkably, removal of Cu(II) ions with an efficiency up to 80% was observed for PSPD-HPGs, whereas no adsorption was found for the PD-free precursor. Collectively, these data show that modification with a biocompatible polymer such as PD provides a simple and valuable tool to enlarge the field of application of polysulfone hollow granules for water remediation from both organic and metal cation contaminants.

A new symmetric oligothiophene exposing tetraethylene glycol (TEG)-based side-chains is designed and synthesized. This molecule is found to self-assemble in solution forming supramolecular fibers, via pi-pi stacking between the conjugated oligothiophene backbones, which are phase segregated on the sub-nanometer scale from the TEG side-groups. The delocalization of the charges through the oligothiophene pi-pi stack ensures efficient charge transport while the hygroscopic shell, decorating the surface of the fibrillar structures, determines a certain affinity for polar molecules. Upon exposure to humidity, under environmental conditions, such supramolecular architectures are capable of reversibly absorbing and desorbing water molecules. Absorption of water molecules, due to increased environmental humidity, causes a fast and reproducible increase of the electrical current through the fibers by a factor 100 from 15% to 90% relative humidity, as measured in 2-terminal devices. Such process is extremely fast, taking place in less than 45 ms. The humidity-responsive characteristics of the presented oligothiophene-based fibers can be exploited for the facile fabrication of high-performances and solution-processable electrical resistive humidity sensors.

A data-matrix (DM)-technology approach in cell biology is implemented as an efficient method for the multiparameter monitoring of cell cultures. The proposed method takes advantage of the know-how developed for fault tolerance in digital information technology by measuring the amount of errors induced by intervening cells upon checking a DM code placed behind them. It gives continuous access to several quantitative parameters of the observed culture, such as cell coverage, mean size, viability, and transfection efficiency.

We report on the investigation of the influence of the molecular packing and film morphology on the field-effect charge mobility in 2,3-thienoimide-based oligothiophenes semiconductors (Cn-NT4N). Organic field-effect transistors are realized by implementing both vacuum and solution methods in order to control the solid-state phase of the active layer. Thermal sublimation in a high vacuum chamber and supersonic molecular beam deposition were used as vacuum-based fabrication approaches for preparing thin films, while lithographically controlled wetting was used, as a solution-deposition technique, for the fabrication of the microstructured films. Thermal sublimation leads to thin films with a phase packing showing ambipolar behaviour, while supersonic molecular beam deposition enables, by varying the deposition rate, the formation of two different crystal phases, showing ambipolar and unipolar field-effect behaviours. On the other hand, lithographically controlled wetting enables the formation of Cn-NT4N microstructured active layers and their implementation in field-effect transistors.

Polysulfone hollow fibers (PS-HF) are widely used in ultrafiltration modules for hemodialysis and drinking water purification for the removal of large colloids, microbes, and viruses. The preparation of commercial PS-HF standard modules leads to the generation of PS-HF scraps in amount higher than 5% of the total production (tons scale) that cannot be used for filtration purposes and represent large volume plastic wastes. Here, a simple approach to convert such high value waste into a new granular material with excellent adsorption properties toward organic compounds is introduced. Polysulfone hollow porous granules (PS-HPG) are prepared by a mechanical grinding process and then exploited for the removal of selected organic compounds from water under flow and batch conditions. Volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons, and also selected emerging organic contaminants (EOCs), including two common drugs (carbamazepine and diclofenac), a plastic additive (bisphenol A), and a textile dye (Rhodamine B), are successfully adsorbed. Regeneration and reuse possibility of PS-HPG are also demonstrated. Additionally, air remediation from VOCs and from airborne nanoparticles is successfully achieved by flowing an air stream through a filtration cartridge filled by PS-HPG

Thienopyrrole-dione (TI) end capped materials have recently emerged as polymorphic molecular semiconductors suitable as active layers of ambipolar light emitting transistors, photovoltaic cells and time temperature integrator devices. Here, we report the synthesis of a new derivative, namely 2,2'-([2,2'-bithiophene]-5,5'-diyl) bis(5-octyl-4-phenyl-4H-thieno[2,3-c] pyrrol-6(5H)-one) (R-NT4N), having monoreduced TI moiety (R-TI) end groups. Ring opening of the TI moiety by Grignard reagent addition followed by one-pot reduction/ring closure by triethylsilane afforded the R-TI precursor that was then exploited for the preparation of the target R-NT4N compound. Investigation of the fluorescence properties of thin films, as a function of the processing conditions, showed that different from all the other TI derivatives so far reported, R-NT4N exhibits linearly polarized fluorescent microstructures. Combined micro-Raman and confocal laser-scanning fluorescence microscopies on lithographically controlled wetting (LCW) patterned R-NT4N films allowed us to correlate the emission polarization directions with the microcrystal structures.

This work explored polysulfone (PS) - graphene oxide (GO) based porous membranes (PS-GO) as adsorber of seven selected organic contaminants of emerging concern (EOCs) including pharmaceuticals, personal care products, a dye and a surfactant from water. PS-GO was prepared by phase inversion method starting from a PS and GO mixture (5% w/w of GO). The porous PS-GO membranes showed asymmetric and highly porous micrometer sized pores on membrane top (diameter ?20 ?m) and bottom (diameter ?2-5 ?m) surfaces and tens of microns length finger like pores in the section. Nanomechanical mapping reveals patches of a stiffer material with Young modules comprised in the range 15-25 GPa, not present in PS pure membranes that are compatible with the presence of GO flakes on the membrane surfaces. PS-GO was immersed in EOCs spiked tap water and the adsorbance efficiency at different contact times and pH evaluated by HPLC analysis. Ofloxacin (OFLOX), benzophenone-3 (BP-3), rhodamine b (Rh), diclofenac (DCF) and triton X-100 (TRX) were removed with efficiency higher than 90% after 4 h treatments. Regeneration of PS-GO and reuse possibilities were demonstrated by washing with ethanol. The adsorption efficiencies toward OFLOX, Rh, DCF and carbamazepine (CBZ) were significantly higher than those of pure PS membrane. Moreover, PS-GO outperformed a commercial granular activated carbon (GAC) at low contact times and compared well at longer contact time for OFLOX, Rh, BP-3 and TRX suggesting the suitability of the newly introduced material for drinking water treatment.