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Mortality in children with kidney failure is higher in girls than boys with cardiovascular complications representing the most common causes of death. Pulse wave velocity (PWV), a measure of vascular stiffness, predicts cardiovascular mortality in adults. Here, PWV in children with kidney failure undergoing kidney replacement therapy was investigated to determine sex differences and potential contributing factors. Two-hundred thirty-five children (80 girls; 34%) undergoing transplantation (150 pre-emptive, 85 with prior dialysis) having at least one PWV measurement pre-and/or post-transplantation from a prospective cohort were analyzed. Longitudinal analyses (median/maximum followup time of 6/9 years) were performed for PWV z-scores (PWVz) using linear mixed regression models and further stratified by the categories of time: pre-kidney replacement therapy and post-transplantation. PWVz significantly increased by 0.094 per year and was significantly higher in girls (PWVz + 0.295) compared to boys, independent of the underlying kidney disease. During pre-kidney replacement therapy, an average estimated GFR decline of 4 ml/min/1.73 m(2) per year was associated with a PWVz increase of 0.16 in girls only. Higher diastolic blood pressure and low density lipoprotein were independently associated with higher PWVz during pre-kidney replacement therapy in both sexes. In girls post-transplantation, an estimated GFR decline of 4ml/min/1.73m(2) per year pre-kidney replacement therapy and a longer time (over 12 months) to transplantation were significantly associated with higher PWVz of 0.22 and of 0.57, respectively. PWVz increased further after transplantation and was positively associated with time on dialysis and diastolic blood pressure in both sexes. Thus, our findings demonstrate that girls with advanced chronic kidney disease are more susceptible to develop vascular stiffening compared to boys, this difference persist after transplantation and might contribute to higher mortality rates seen in girls with kidney failure., German Federal Ministry of Education and Research [01EO0802]; European Renal Association -European Dialysis and Transplant Association; Roche Organ Transplant Research Foundation [365520785], This study was made possible by grants from the German Federal Ministry of Education and Research (#01EO0802), the European Renal Association -European Dialysis and Transplant Association (www.eraedta.org), and Roche Organ Transplant Research Foundation (#365520785). Several coauthors are members of the European Rare Kidney Disease Reference Network (ERKNet). This study has been presented as an abstract at the TTS (The Transplantation Society) 2020 Virtual Congress on September 14, 2020.

[No Abstract Available], German Federal Ministry of Education and Research [01EO0802]; European Renal Association-European Dialysis and Transplant Association; Roche Organ Transplant Research Foundation [365520785], This study was made possible by grants from the German Federal Ministry of Education and Research (no. 01EO0802), the European Renal Association-European Dialysis and Transplant Association, and Roche Organ Transplant Research Foundation (no. 365520785). Several co-authors are members of the European Reference Network for Rare Kidney Diseases.

Mass production of defect-free single-layer graphene flakes (SLGFs) by a cost-effective approach is still very challenging. Here, we report such single-layer graphene flakes (SLGFs) (>90%) prepared by a nondestructive, energy-efficient, and easy up-scalable physical approach. These high-quality graphene flakes are attributed to a novel 10 s microwave-modulated solid-state approach, which not only fast exfoliates graphite in air but also self-heals the surface of graphite to remove the impurities. The fabricated high-quality graphene films (∼200 nm) exhibit a sheet resistance of ∼280 Ω/sq without any chemical or physical post-treatment. Furthermore, graphene-incorporated Ni-Fe electrodes represent a remarkable ∼140 mA/cm2 current for the catalytic water oxidation reaction compared with the pristine Ni-Fe electrode (∼10 mA/cm2) and a 120 mV cathodic shift in onset potential under identical experimental conditions, together with a faradic efficiency of >90% for an ideal ratio of H2 and O2 production from water. All these excellent performances are attributed to extremely high conductivity of the defect-free graphene flakes.

Developing easy and effective surface functionalization approaches has required to facilitate the processability of graphene while seeking novel application areas. Herein, an in situ single-step reductive covalent bromination of graphene has been reported for the first time. Highly brominated graphene flakes (>3% Br) were prepared by only subjecting the bromine-intercalated graphite flakes to a reduction reaction with reactive lithium naphthalide. The bromine-functionalized graphene was characterized by X-ray photoelectron spectroscopy and thermogravimetric analysis. Results revealed that Br2 molecules acted as both an intercalating agent for the graphite and a reactant for the surface functionalization of the graphene. After brominating, the remaining negative charges on the reduced graphene surface were further used for the dual surface functionalization of graphene with a long-chain alkyl group (∼1% dodecyl group addition). The functionalized graphenes were also characterized by Fourier transform infrared and Raman spectroscopy.

Solar-driven CO2 reduction by abundant water to alcohols can supply sustainable liquid fuels and alleviate global warming. However, the sluggish water oxidation reaction has been hardly reported to be efficient and selective in CO2 conversion due to fast charge recombination. Here, using transient absorption spectroscopy, we demonstrate that microwave-synthesised carbon-dots (mCD) possess unique hole-accepting nature, prolonging the electron lifetime (t50%) of carbon nitride (CN) by six folds, favouring a six-electron product. mCD-decorated CN stably produces stoichiometric oxygen and methanol from water and CO2 with nearly 100% selectivity to methanol and internal quantum efficiency of 2.1% in the visible region, further confirmed by isotopic labelling. Such mCD rapidly extracts holes from CN and prevents the surface adsorption of methanol, favourably oxidising water over methanol and enhancing the selective CO2 reduction to alcohols. This work provides a unique strategy for efficient and highly selective CO2 reduction by water to high-value chemicals., Solar-driven CO2 reduction by abundant water to alcohols is hindered by the sluggish water oxidation reaction. Here, the authors demonstrate that the microwave-synthesized carbon-dots possess unique hole-accepting nature, allowing stoichiometric oxygen and methanol production from water and CO2 with nearly 100% selectivity to methanol.

We investigated the relationship between crystallinity, deep trap states and PEC performance of g-C3N4 photoelectrodes. Long-lived charge carriers were present in the more poorly crystalline samples, due to deeper trap states, which inversely correlated with photoelectrochemical performance. The charge diffusion length in a compact g-C3N4 film was determined to be ca. 1000 nm.

Nanoplasmonic biosensing shows an immense potential to satisfy the needs of the global health industry - low-cost, fast, and portable automated systems; highly sensitive and real-time detection; multiplexing and miniaturization. In this review, we presented the theory of nanoplasmonic biosensing for popular detection schemes - SPR, LSPR, and EOT - and underline the consideration for nanostructure design, material selection, and their effects on refractometric sensing performance. Later, we covered the bottom-up and top-down nanofabrication methods for nanoplasmonic biosensors. Subsequently, we reviewed the recent examples of nanoplasmonic biosensors over a wide range of clinically relevant analytes in the diagnosis and prognosis of a wide range of diseases and conditions such as biomarker proteins, infectious bacteria, viral agents. Finally, we discussed the challenges of nanoplasmonic biosensing toward clinical translation and proposed strategic avenues to be competitive against current clinical detection methods. Hopefully, nanoplasmonic biosensing can realize its potential through successful demonstrations of clinical translation in the upcoming years.

Microwave-promoted continuous flow systems have emerged as a game-changer in nanoparticle synthesis. Owing to the excellent compatibility between fast, sustainable microwave heating and one-step, efficient flow chemistry, this promising technology is meant to enhance the synthetic abilities of nanoscientists. This Perspective aims to present a panoramic view of the state of the art in this field. Additionally, the effect of various microwave and flow parameters on the properties of nanoparticles is discussed along with a comparative glance at the features that make flow reactors more practical and sustainable than their batch counterparts. The overview has also analyzed various microwave continuous flow reactors available in the literature, with an acute emphasis on the nanosynthesis route and design features. Moreover, a discussion on the numerical modeling of microwave flow systems has been made a part of this perspective to reiterate its significance and encourage research in this domain. The Perspective also briefly comments on existing challenges and future prospects of this technology.

Biodegradable poly(glycerol sebacate) [PGS] has gained substantial attention in the soft tissue engineering field over the past few years, but its application is limited because its fast degradation rate causes an acidic environment which can adversely affect cell viability and eventually tissue growth. β-tricalcium phosphate (β-TCP) is an ideal biocompatible candidate to mitigate these drawbacks of PGS. This work for the first time rationalizes a biocomposite composed of PGS and β-TCP prepared by a fast and well-controlled microwave approach. As expected, the presence of β-TCP particles (i) improves the degree of cross-linking of PGS, thus decreasing the sol content by ca. 66%, (ii) enhances its hydrophilicity with much lower contact angle, (iii) reduces the degradation rate by a factor of two and (iv) increases the swelling effect of the biocomposite by ca. 10%. Furthermore both PGS/β-TCP150 and PGS/β-TCP180 biocomposites demonstrate significant difference in cell viability form the single PGS materials, which is more than 65% higher in cell growth in one day proliferation, demonstrating an advanced biomaterial embodying both advantages of PGS polymer and β-TCP bioceramics. Keywords: Composite, Hydrophilicity, Degree of cross-linking, Degradation rate, Cell proliferation

The attachment of flexible spacers into aromatic polymers is a molecular design approach that is used for improving processability of aromatic polymers. The concept is attractive because it enables not only the creation of aromatic polymers with improved processability but it is also possible to control phase morphology by simply introducing pendant side chains. Here we report new bisphenol A derivatives bearing alkyl chains of different lengths obtained by an addition reaction can readily make novel poly(arylene sulfone)s with aromatic dihalides and aromatic dioles. They were observed using two-dimension diffusion-ordered spectroscopy nuclear magnetic resonance (2D DOSY NMR) spectra. Attaching flexible alkyl groups into sulfonated poly(arylene sulfone)s allows for increased control of glass transition temperatures, T g , of sulfonated poly(arylene sulfone)s. The alkylated sulfonated poly(arylene sulfone)s had flexibility, increased surface contact angle, improved methanol permeability, and high ion conductivity compared to the neat polymer. Due to the creation of aromatic polymers with improved processability by simply introducing pedant side chains, this novel alkylation method is expected to be applicable to other arylene based proton conductive polymers.

Poly(glycerol sebacate) (PGS) is known as an exciting biomaterial owing to its tunable mechanical properties and controllable degradation rate. However, it is always challenging to control these properties. In this study, we have proposed a solvent-based system to provide a better control of reaction temperature in a microwave cavity, which can minimize evaporation of monomers, and water was collected to analyse the degree of esterification. Pre-PGSs with varied degrees of esterification were prepared using both single mode and multimode microwave cavity irradiation (MI) in this solvent-based reaction system. For a similar degree of esterification of pre-PGSs, the reaction time was almost halved with a better control on mechanical properties by single mode MI compared to multimode MI. Furthermore, the single mode MI approach was compared with the conventional heating (CH) approach. The mechanical properties and degradation rate of PGSs can be controlled readily by using the single mode MI approach compared to CH, which are crucial for their application as a biomaterial. It has been found that the single mode MI not only accelerates the pre-polymerisation process rate by six times, but also speeds up the curing time to the same extent. The Young's modulus of PGSs prepared by single mode MI is increased from 0.77 to 3.14 MPa when the degree of esterification is 66.82%, which is 50% higher than that reported in the literature. Furthermore, PGS using a highly branched pre-PGS prepared by the single mode MI method has a large degree of flexibility. It can achieve a much higher Young's modulus than that obtained by CH with a short curing time (

The dimensional stability and barrier properties of proton exchange membranes are critical issues for high-performance proton exchange membrane fuel cells (PEMFCs). In this work, we introduce a viable and effective strategy for preparing high proton-conductive polymer membranes with remarkable dimensional stability and barrier properties. Sulfonated poly(arylene sulfone)s (sPASs) with a UV-crosslinkable monomer, 2,2′-diallylbisphenol A (DABPA), is successfully synthesized via condensation polymerization, showing competitive molecular weights and sulfonation degrees to the neat polymer. Crosslinked nanocomposite membranes can be fabricated by incorporating soft bridge molecules and exfoliated LAPONITE® nanofillers, and subsequent UV-crosslinking. The sPAS–LAPONITE® nanocomposite membranes show greatly improved dimensional stabilities and barrier properties including remarkably reduced swelling ratio in solvent or methanol aqueous solutions. These enhanced properties lead to excellent performance in a direct methanol fuel cell (DMFC) test, surpassing that of a commercially available Nafion membrane based devices.

We investigated the relationship between crystallinity, deep trap states and PEC performance of g-C

Graphitic carbon nitride (g‐C3N4) is a metal‐free semiconductor that has been widely regarded as a promising candidate for sustainable energy production or storage. In recent years, g‐C3N4 has become the center of attention by virtue of its impressive properties, such as being inexpensive, easily fabricable, nontoxic, highly stable, and environment friendly. Herein, the recent research developments related to g‐C3N4 are outlined, which sheds light on its future prospective. Various synthetic methods and their impact on the properties of g‐C3N4 are detailed, along with discussion on frequently used characterization methods. Different approaches for g‐C3N4 surface functionalization, mainly categorized under covalent and noncovalent strategies, are outlined. Moreover, the processing methods of g‐C3N4, such as g‐C3N4‐based thin films, hierarchical, and hybrid structures, are explored. Next, compared with the extensively studied energy‐related applications of the modified g‐C3N4s, relatively less‐examined areas, such as environmental and sensing, are presented. By highlighting the strong potential of these materials and the existing research gaps, new researchers are encouraged to produce functional g‐C3N4‐based materials using diverse surface modification and processing routes.

The development of energy efficient, reproducible, and high throughput approaches to gold nanoparticle (Au-NP) synthesis has gained increasing attention over the past decades due to applications in biomedicine, sensors, and catalysis. In this work, single mode microwave irradiation is for the first time combined with microflow chemistry to fabricate Au-NPs continuously and reproducibly with controllable size in an aqueous solution. The major experimental parameters including microwave power, citrate-to-gold molar ratio ([Cit]/[Au]), and reaction residence time have been investigated systematically. As indicated by TEM, the mean particle width of the synthesized Au-NPs is between 4 and 15 nm with mean aspect ratio between ∼1.4 and 2.2 after only 90 s of microwave irradiation. Furthermore, the Au particle morphology can be manipulated from nanowires to nanoparticles by adjusting the [Cit]/[Au] ratio. HRTEM analysis of the produced Au-NPs and UV–vis spectroscopy suggests a correlation between the red-shifted...

Nanocystalline TiO2 particles were successfully synthesized on porous hosts (SBA-15 and ZSM-15) via a sol-gel impregnation method. Resulting nanocomposites were characterized by XRD, TEM, BET surface analysis, Raman and UV-vis diffuse reflectance spectroscopy, and their photocatalytic activity for H2 production evaluated. XRD evidences the formation of anatase nanoparticles over both ZSM-5 and SBA-15 porous supports, with TEM highlighting a strong particle size dependence on titania precursor concentration. Photocatalytic activities of TiO2/ZSM-5 and TiO2/SBA-15 composites were significantly enhanced compared to pure TiO2, owing to the smaller TiO2 particle size and higher surface area of the former. TiO2 loadings over the porous supports and concomitant photocatalytic hydrogen production were optimized with respect to light absorption, available surface reaction sites and particle size. 10%TiO2/ZSM-5 and 20%TiO2/SBA-15 proved the most active photocatalysts, exhibiting extraordinary hydrogen evolution rates of 10,000 and 8800μmolgTiO2 -1 h-1 under full arc, associated with high external quantum efficiencies of 12.6% and 5.4% respectively under 365nm irradiation.

In this work, a microwave promoted flow (MWPF) system to reproducibly synthesize self-assembled hierarchical hematite superstructures (Hem-SSs) using the sole precursor (Fe(NO3)3·9H2O) and single mode microwave under aqueous conditions was developed. The functional characterisation by XRD, (HR)TEM, XPS, UV-vis and Raman spectroscopy proved that highly crystalline ellipsoid Hem-SSs (∼180 nm × 140 nm) were produced, built from primary hematite nanoparticles, 5–10 nm in size using 0.05 mol L−1 precursor concentration, 1 mL min−1 flow rate and short reaction time (about 6 min). Particles produced via conventional heating (CH) at 120 and 140 °C in the same flow reactor under similar experimental conditions were found to consist of mixtures of goethite and hematite. The effects of precursor concentration (0.1 and 0.2 mol L−1) and flow rate (2 and 5 mL min−1) were further investigated and the synthesis mechanism was also discussed. This novel method opens a window for continuous fabrication of metal or metal oxide nanoparticles/superstructures by a green approach.

Azobenzene polymers have great potential and impact on fundamental and applied research. However little is known about their thermal stability and degradation behaviours. Herein, nine conjugated main chain azobenzene polymers were synthesized using the nitroamine derivatives of some diphenylene compounds such as 4-amino-4′-nitrobiphenyl 1, 4-amino-4′-nitrobiphenyl ether 2 and 4-amino-4′-nitrobiphenyl sulfide 3, and comonomers triphenylamine A, N-methyldiphenyl amine B and triphenylphosphine C via diazo coupling reaction. These heteroatom containing polymers were characterized by 1H- and 31P-NMR, FTIR, UV–Vis and Raman spectroscopy. The thermal stability and degradation behaviour of these polymers were studied by means of TGA technique. Electronic spectra of the polymers recorded in DMF showed two strong maxima at ca. 280 and 380 nm. They were resistant to heat up to 270 °C and, produced 41-61% char under a nitrogen atmosphere at 800 °C. UL 94 burning tests performed for TPU Ravathane® (TPE-U) with added azobenzene polymer revealed that these polymers could be used as an intumescent reactive flame retardant additive, particularly for polyurethanes and elastomers, due to their high char yield at relatively high temperatures (e.g 800 °C). The carbonized materials were further characterized by XRD and SEM/EDX.

Many studies have been conducted on organic and inorganic synthesis by microwave heating owing to its special heating mechanism, leading to improved reaction rate, higher purity and yields. We specifically demonstrated microwave heating in the fabrication of nanoparticles and polyester. By fine-tuning the microwave and experimental parameters, the materials prepared have shown excellent physical and bio-properties, e. g. narrow particle size distribution, controlled morphology, varied molecular structure and so forth. We further highlight the recent procedure of using fluidic reactors on preparing both metals and metal oxides nanoparticles. The experimental design strategies and fundamentals of the microwave interaction with chemicals are presented. Furthermore, the key factors and issues facing in this area are also discussed.

Carbon nanotubes (CNTs) are ideal support materials for platinum in fuel cells. However, little is known about the conduction mechanism of Pt-coordinated CNTs. Herein, a coordination complex of pyridine-functionalized single-walled nanotubes (Py-SWNTs) with Pt (Pt/Py-SWNTs) was prepared via the ligand exchange reaction between cis-[Pt(dmso)2Cl2] and Py-SWNTs generated by pyridine diazonium salt addition to SWNTs. The presence of Pt in modified SWNTs was confirmed by X-ray photoelectron spectroscopy (XPS). The N 1s XPS spectra provided evidence of Pt coordination to the pyridine nitrogen atom. Modified SWNTs were further characterized by thermogravimetric analysis coupled with mass spectrometry, ultraviolet-visible-near infrared spectroscopy, Raman spectroscopy, and elemental analysis. The electron conduction mechanism of Pt/Py-SWNT films was best described by a modified quantum tunneling model, identified from a combined analysis of the voltage and temperature dependence of the current.

Poly(ethylene glycol) [1, PEG(similar to 4)(OH)2, M-n similar to 2001, glycerol ethoxylate [2, PEG(similar to 21)(OH)3, M-n similar to 1000] and pentaerythritol ethoxylate [3, PEG(similar to 15)(OH)(4), M-n similar to 797] react directly with phenyl-C-61-butyric acid methyl ester (PCBM), in the presence of dibutyltinoxide (DBTO) catalyst at 140 degrees C, to give a mixture of fullerene [C-60] end-capped PEGs via transesterification. Among these PEG linkers, only PEG(similar to 4)(OPCB)(2) (4a) (OPCB: ester oxygen linked phenyl-C-61-butyryl group) was successfully isolated from the crude product mixture in the fully end-capped form. Fully acylated PEG(similar to 21)(OPCB)(3) (5) and PEG(similar to 15)(OPCB)(4) (6) could not be separated chromatographically from incompletely reacted species due to the polydispersity in branch lengths. This purification challenge was overcome by using a monodisperse branched core, 1,3,5-tris-(Octagoloxymethyl)benzene [7, PEG(24)(OH)(3)] to give a monodisperse tris-fullerene homostar, PEG(24)(OPCB)(3) (8). The structures of the bis- and tris-fullerene products were confirmed by MALDI-TOF mass spectrometry and H-1 NMR spectroscopy with supporting FTIR and UV-vis spectroscopic analysis.

Pyridinium ylide functionalized single-walled carbon nanotubes (SWCNTs) generated from simple quaternary pyridinium salts covalently bound to the SWCNT surface undergo a 1, 3 dipolar cycloaddition with dimethyl acetylenedicarboxylate in a ‘click’ chemistry type fashion to yield indolizine modified light-emitting SWCNTs. Conversion of quaternary pyridinium salts into indolizines on the SWCNT surface was confirmed by XPS, fluorescence spectroscopy and optical microscopy. The resulting modified SWCNTs were found to emit blue light when excited at 330 nm. Fluorescence quenching experiments performed via nitroaromatic compounds displayed that the fluorescence of the modified SWCNTs was quenched by nitrophenol derivatives in both solution-state and solid-state, probably due to strong H-bonding interaction between host and guest molecules. The functionalized SWCNTs were further characterized using TGA-MS, FTIR and UV-vis-NIR spectroscopy.

For the first time, a one-step scalable synthesis of a few-layer ∼10% nitrogen doped (N-doped) graphene nanosheets (GNSs) from a stable but highly reactive 1,3-dipolar organic precursor is reported. The utilization of these N-doped GNSs as metal-free electrocatalysts for the oxygen evolution reaction (OER) is also demonstrated. This process may open the path for the scalable production of other heteroatom doped GNSs by using the broad library of well-known, stable 1,3-dipolar organic compounds.

Synthesis, characterization and the direct use of d imethyl 3-(4-aminophenyl)indolizine-1,2dicarboxylate (1) as a photochemical sensor for the solution phase d etection of nitroaromatics are presented. Fluorescent quenching experiments depict that nitroaromatics, particularly nitrophenol derivatives, may be probed by diester 1 with a detection limit of 6.66 ◊ 10 -8 M. FTIR and 1 H NMR studies together with fluorescent spectral anal ysis suggest that H-bonding interaction between 1 and p-nitrophenol (2d) triggers the formation of ground-state complex (1:2d) which causes the fluorescent quenching via electron trans fer from the HOMO of electron-rich indolizine to the LUMO of electron-deficient nitrop henolics through hydrogen bonding.

Herein, a versatile method to introduce ester functional groups to the surface of single-walled carbon nanotubes (SWCNTs) was defined. Ester-modified SWCNTs were prepared via the direct reaction of haloformates with reduced SWCNTs [(nBu–SWCNT n− ) Li + ] generated by n-butyl lithium. Ultraviolet–Visible–near infrared and Raman spectroscopy verified the evidence of covalent surface functionalization. Solubility of functionalized SWCNTs (f-SWCNTs) enhanced compared to purified SWCNTs. Gold tagging to positively charged SWCNTs displayed the presence and distribution of functional groups, confirming the conversion of esters into amides. f-SWCNTs were further characterized by thermo-gravimetric analysis coupled with mass spectrometry and fourier-transform infrared spectroscopy.

Covalently interconnected single walled carbon nanotube (SWNT) networks have attracted a particular interest due to their enhanced accessible surface area. Herein, an elegant way of preparing covalently interconnected SWNTs is demonstrated for the first time via coupling reactions. Sonogashira and Ullmann coupling reactions offer a versatile route for the preparation of molecularly-bridged SWNTs (MBSWNTs). Couplings create C C bonds between SWNTs yielding MBSWNTs with conductive 1,2-diphenyl-diacetylene and biaryl bridges. Elemental composition analysis done by XPS shows the evidence of successful couplings while mass traces of the interconnected SWNTs corroborating with fragmentations corresponding to conjugated linkers.

Pyridine-functionalized single-walled carbon nanotubes (SWNTs) are prepared from the addition of a pyridine diazonium salt to nanotubes. The location and distribution of the functional groups is determined by atomic force microscopy using electrostatic interactions with gold nanoparticles. The pyridine-functionalized SWNTs are able to act as cross-linkers and hydrogen bond to poly(acrylic acid) to form SWNT hydrogels. The pyridine-functionalized SWNTs are further characterized using Raman, FTIR, UV/vis-NIR, and X-ray photoelectron spectroscopy and thermogravimetric analysis-mass spectrometry.

Formyl or aldehyde groups are transferred to the surface of single-walled carbon nanotubes (SWCNTs) by reaction of reduced carbon nanotubes with N-formylpiperidine. This could open the way for more versatile chemical modification reactions of carbon nanotubes than is currently possible using functionalization methods reported to date. The formylated SWCNTs were characterized by thermogravimetric analysis-mass spectrometry and Raman, UV-vis-NIR and FTIR spectroscopy. The location and distribution of the functional groups was determined by AFM using electrostatic interactions with gold nanoparticles. The formylated SWCNTs were further derivatized with a fluorescent dye and studied using fluorescence spectroscopy. (C) 2010 Elsevier Ltd. All rights reserved.

The bandgap engineering of semiconductors, in particular low‐cost organic/polymeric photocatalysts could directly influence their behavior in visible photon harvesting. However, an effective and rational pathway to stepwise change of the bandgap of an organic/polymeric photocatalyst is still very challenging. An efficient strategy is demonstrated to tailor the bandgap from 2.7 eV to 1.9 eV of organic photocatalysts by carefully manipulating the linker/terminal atoms in the chains via innovatively designed polymerization. These polymers work in a stable and efficient manner for both H2 and O2 evolution at ambient conditions (420 nm < λ < 710 nm), exhibiting up to 18 times higher hydrogen evolution rate (HER) than a reference photocatalyst g‐C3N4 and leading to high apparent quantum yields (AQYs) of 8.6%/2.5% at 420/500 nm, respectively. For the oxygen evolution rate (OER), the optimal polymer shows 19 times higher activity compared to g‐C3N4 with excellent AQYs of 4.3%/1.0% at 420/500 nm. Both theoretical modeling and spectroscopic results indicate that such remarkable enhancement is due to the increased light harvesting and improved charge separation. This strategy thus paves a novel avenue to fabricate highly efficient organic/polymeric photocatalysts with precisely tunable operation windows and enhanced charge separation.

WOS:000268898300082 The preparation of new poly(urethane-imide)s (PUIs) having acceptable thermal stability and higher flame resistance was aimed. Two new aromatic diisocyanate-containing methyldiphenylphosphine oxide and triphenylphosphine oxide moieties were synthesized via Curtius rearrangement in situ and polymerized by various prepared diols. Four aliphatic hydroxy terminated aromatic based diols were synthesized by the reaction between ethylene carbonate and various diphenolic Substances. Chemical structures of monomers and polymers were characterized by FTIR, (1)H NMR, (13)C NMR, and (31)P NMR spectroscopy. Thermal stabilities and decomposition behaviors of the PUIs were tested by DSC and TGA. Thermal measurements indicate that the polymers have high thermal stability and produce high char. Polymers exhibit quite high fire resistance, evaluated by fire test UL-94. The films of the polymers were prepared by casting the solution. Inherent viscosities, solubilities, and water absorbtion behaviors of the polymers were reported in. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114:1329-1338, 2009

Gold nanoparticles (AuNPs) can be evenly deposited on single-walled carbon nanotubes (SWCNTs) via the reduction of the highly stable complex, chloro(triphenylphosphine) gold(I), with SWCNT anions ('nanotubides'). This methodology highlights the unusual chemistry of nanotubides and provides a blueprint for the generation of many other hybrid nanomaterials.

Sonicating pure N-methyl pyrrolidone (NMP) rapidly produces contaminating organic nanoparticles, at increasing concentration with time, as investigated by AFM, as well as UV-vis, IR and NMR spectroscopies. The contamination issue affects carbon nanotube, and likely other nanomaterial, dispersions processed by sonication in organic solvents.

Previously, reduced single-walled carbon nanotube anions have been used for effective processing and functionalization. Here we report individually separate and distinct (that is, discrete) single-walled carbon nanotube cations, directly generated from a pure anode using a non-aqueous electrochemical technique. Cyclic voltammetry provides evidence for the reversibility of this nanoion electrochemisty, and can be related to the complex electronic density of states of the single-walled carbon nanotubes. Fixed potentiostatic oxidation allows spontaneous dissolution of nanotube cations ('nanotubium'); Raman spectroscopy and transmission electron microscopy show that sequential fractions are purified, separating amorphous carbon and short, defective single-walled carbon nanotubes, initially. The preparation of nanotubium, in principle, enables a new family of nucleophilic grafting reactions for single-walled carbon nanotubes, exploited here, to assemble nanotubes on amine-modified Si surfaces. Other nanoparticle polyelectrolyte cations may be anticipated.

Selective covalent surface modification of single-walled carbon nanotubes (SWNTs) is of great importance to various carbon nanotube-based applications as it might offer an alternative method for enriching metallic and semiconducting nanotubes. Herein, we report on the surface modification of SWNTs through 1,3-dipolar cycloaddition of 3-phenyl-phthalazinium-1-olate, which is a stable and reactive azomethine imine. For this reaction, microwave heating was found to be more efficient than conventional and solvent-free heating. The sensitivity of cycloaddition to the molecular structure of SWNTs was probed using resonance Raman spectroscopy with three different laser excitations. Based on the obtained results, azomethine imine addition to the surface of nanotubes is selective for metallic and large-diameter semiconducting SWNTs. Thermogravimetric analysis coupled with mass spectrometry showed that fragments released at high temperatures corresponded to the phenylphthalazine group, thus confirming the covalent surface functionalization. Modified SWNTs were further characterized by X-ray photoelectron and UV/Vis-NIR spectroscopies.

Single-walled carbon nanotubes (SWNTs) are a fundamental family of distinct molecules, each bearing the possibility of different reactivities due to their intrinsically distinct chemical properties. SWNT syntheses generate a heterogeneous mixture of species with varying electronic character, lengths, diameters and helicities, (n,m), as well as other amorphous, graphitic and metal catalyst impurities. In recent years, selective syntheses and post-synthetic separation strategies have advanced, driven by the requirement for pure SWNTs displaying particular features. Covalent surface modifications are widely-used to adapt SWNTs for specific applications with modified solubility, compatibility and specific functionalities. In many cases, such reactions have been found to be selective, illuminating the fundamentally distinct chemistry of each (n,m) species. This differential reactivity has found immediate utility in facilitating the sorting of nanotubes according to specific diameter, electronic properties and, most importantly, helicity. In this tutorial review, we discuss a wide range of selective reactions, the mechanisms that are thought to govern selectivity, and the challenges of separating, characterising and regenerating the modified SWNTs.

Pyridinium ylides generated from simple Krohnke salts undergo a 1,3-dipolar cycloaddition to single-walled carbon nanotubes (SWNTs) offering a simple and convenient method for the covalent modification of carbon nanotubes. The indolizine functionalized SWNTs generated, emit blue light when excited at 335 nm. The location and distribution of the functional groups was determined by AFM using electrostatic interactions with gold nanoparticles. While resonance Raman spectroscopy showed that the 1,3-dipolar cylcloaddition of the pyridinium ylides to the nanotube surface was selective for metallic and large diameter semiconducting SWNTs. The indolizine functionalized SWNTs were further characterized using FTIR, UV-vis-NIR, TGA-MS, and XPS.