Ambient Catalytic Spinning of Polyethylene Nanofibers.

A novel single-atom Ni(II) catalyst (Ni-OH) is covalently immobilized onto the nano-channels of mesoporous Santa Barbara Amorphous (SBA)-15 particles and isotropic Anodized Aluminum Oxide (AAO) membrane for confined-space ethylene extrusion polymerization. The presence of surface-tethered Ni complexes (Ni@SBA-15 and Ni@AAO) is confirmed by the inductively coupled plasma-optical emission spectrometry (ICP-OES) and X-ray photoelectron spectroscopy (XPS). In the catalytic spinning process, the produced PE materials exhibit very homogeneous fibrous morphology at nanoscale (diameter: ~50 nm).

Melanized-Cationic Cellulose Nanofiber Foams for Bioinspired Removal of Cationic Dyes.

In recent years, water pollution has developed into a severe environmental and public health problem due to rapid urbanization and industrialization, especially in some developing countries. Finding solutions to tackle water pollution is urgently required and is of global importance. Currently, a range of water treatment methods are available; however, a water remediation process that is simple, inexpensive, eco-friendly, and effective for the removal of pollutants down to ppm/ppb concentrations has long been sought after.

Release of graphene-related materials from epoxy-based composites: characterization, quantification and hazard assessment in vitro.

Due to their mechanical strength, thermal stability and electrical conductivity, graphene-related materials (GRMs) have been extensively explored for various applications. Moreover, GRMs have been studied and applied as fillers in polymer composite manufacturing to enhance the polymer performance. With the foreseen growth in GRM production, occupational and consumer exposure is inevitable, thus raising concerns for potential health risks.

Scalable Biosynthesis of Melanin by the Basidiomycete Armillaria cepistipes.

Natural melanin features many interesting properties, including the ability to shield electromagnetic radiation, the ability to act as scavenger for radical and reactive oxygen species and the capacity to chelate different metal ions. For these reasons, melanin is becoming increasingly relevant for the development of functional materials with potential applications in cosmetics, drug delivery, and water purification. However, the extraction and purification of melanin from conventional sources (e.

Extraction of Biofilms From Ureteral Stents for Quantification and Cultivation-Dependent and -Independent Analyses.

Ureteral stenting is a common surgical procedure, which is associated with a high morbidity and economic burden, but the knowledge on the link between biofilms on these stents, morbidity, and the impact of the involved microbiota is still limited. This is partially due to a lack of methods that allow for a controlled extraction of the biofilms from stents. Development of an appropriate model to assess prevention of biofilm formation by antimicrobial coatings and biomaterials requires a profound understanding of the biofilm composition, including the involved microbiota.

Improving the Stability of Amino-Containing Plasma Polymer Films in Aqueous Environments.

Plasma polymer films that contain amine groups (NH-PPFs) are known to degrade over time, particularly in aqueous environments. To reduce such aging effects, a vertical chemical gradient regarding the amine group density was explored ranging over a few nanometers at the coating surface. The gradient-containing nanofilms were formed in low-pressure plasma by tuning plasma conditions while keeping the plasma "switched on".

Affinity-Driven Immobilization of Proteins to Hematite Nanoparticles.

Functional nanoparticles are valuable materials for energy production, bioelectronics, and diagnostic devices. The combination of biomolecules with nanosized material produces a new hybrid material with properties that can exceed the ones of the single components. Hematite is a widely available material that has found application in various sectors such as in sensing and solar energy production.

Interaction of graphene-related materials with human intestinal cells: an in vitro approach.

Graphene-related materials (GRM) inherit unique combinations of physicochemical properties which offer a high potential for technological as well as biomedical applications. It is not clear which physicochemical properties are the most relevant factors influencing the behavior of GRM in complex biological environments. In this study we have focused on the interaction of GRM, especially graphene oxide (GO), and Caco-2 cells in vitro.

Rapid Assay to Assess Bacterial Adhesion on Textiles.

Textiles are frequently colonized by microorganisms leading to undesired consequences like hygienic problems. Biocidal coatings often raise environmental and health concerns, thus sustainable, biocide-free coatings are of interest. To develop novel anti-adhesive textile coatings, a rapid, reliable, and quantitative high-throughput method to study microbial attachment to fabrics is required, however currently not available.

Suppression of Hydrophobic Recovery by Plasma Polymer Films with Vertical Chemical Gradients.

Vertical chemical gradients extending over a few nanometers were explored. The gradients are based on plasma-polymerized oxygen-containing ethylene (ppOEt) films. Using plasma conditions with low CO2/C2H4 ratio and high energy input, cross-linked films were deposited as base layer, while increasing CO2 and lowering energy input resulted in less cross-linked yet highly functional films as applied as top layer.

Absorbing TiO thin film enabling laser welding of polyurethane membranes and polyamide fibers.

We report on the optical properties of thin titanium suboxide (TiO ) films for applications in laser transmission welding of polymers. Non-absorbing fibers were coated with TiO coatings by reactive magnetron sputtering. Plasma process parameters influencing the chemical composition and morphology of the deposited thin films were investigated in order to optimize their absorption properties.

Ultrathin, flexible, and transparent polymer multilayer composites for the protection of silver surfaces.

Silver coatings at the nanoscale became of high interest for the integration of electronic functionalities on all kinds of objects for daily use. In these thin coatings, corrosion is a big problem as it destroys these thin layers and leads to a loss of conductivity due to missing bulk material. For protection of thin silver coatings against H(2)S induced corrosion, we developed nanocoatings based on the covalent layer-by-layer technique.

Decaborane thiols as building blocks for self-assembled monolayers on metal surfaces.

Three nido-decaborane thiol cluster compounds, [1-(HS)-nido-B(10)H(13)] 1, [2-(HS)-nido-B(10)H(13)] 2, and [1,2-(HS)(2)-nido-B(10)H(12)] 3 have been characterized using NMR spectroscopy, single-crystal X-ray diffraction analysis, and quantum-chemical calculations. In the solid state, 1, 2, and 3 feature weak intermolecular hydrogen bonding between the sulfur atom and the relatively positive bridging hydrogen atoms on the open face of an adjacent cluster. Density functional theory (DFT) calculations show that the value of the interaction energy is approximately proportional to the number of hydrogen atoms involved in the interaction and that these values are consistent with a related bridging-hydrogen atom interaction calculated for a B(18)H(22)·C(6)H(6) solvate.

Tuning the surface potential of Ag surfaces by chemisorption of oppositely-oriented thiolated carborane dipoles.

Two selected carboranethiol isomers were used to modify flat silver surfaces. Both isomers, 1,2-(HS)(2)-1,2-C(2)B(10)H(10) (a) and 9,12-(HS)(2)-1,2-C(2)B(10)H(10) (b), are relatively strong dipoles with two SH groups per molecule. They are both anchored to the surface via two SH groups per molecule.

High-resolution cavity ringdown spectroscopy of the jet-cooled propyl peroxy radical C(3)H(7)O(2).

We have obtained high resolution, partially rotationally resolved, jet-cooled cavity ringdown spectra of the origin band of the A<--X electronic transition of two of the five conformers (G(1)G(2) and G(1)T(2)) of the normal propyl peroxy radical, C(3)H(7)O(2), as well as the G conformer of the iso-propyl peroxy radical isomer. This transition, located in the near infrared, was studied using a narrow band laser source (less than or approximately 250 MHz) and a supersonic slit-jet expansion coupled with an electric discharge allowing us to obtain rotational temperatures of about 15 K. All three spectra have been successfully fitted using an evolutionary algorithm approach with a Hamiltonian including rotational and spin-rotational terms.

High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2.

We have recorded high resolution, partially rotationally resolved, jet-cooled cavity ringdown spectra of the origin band of the A-X electronic transition of both the G and T conformers of the perproteo and perdeutero isotopologues of the ethyl peroxy radical, C(2)H(5)O(2). This transition, located in the near infrared, was studied using a narrow band laser source (< or approximately 250 MHz) and a supersonic slit-jet expansion coupled with an electric discharge allowing us to obtain rotational temperatures of about 15 K. All four spectra have been successfully simulated using an evolutionary algorithm approach with a Hamiltonian including rotational and spin-rotational terms.

The structure and spectra of organic peroxy radicals.

Recent spectroscopic and computational work on organic peroxy radicals, RO(2), is reviewed and extended with an emphasis on radicals where R is an alkyl group. Detailed experimental spectral, structural relationships are developed and show the dependence of spectral properties on the number of carbon atoms in the radical, and its isomeric and conformeric structure. These empirical relationships are explored and rationalized with the help of a series of quantum chemistry calculations, which are in turn benchmarked by the experimental data.

Observation of the A-x electronic transition of the isomers and conformers of pentyl peroxy radical using cavity ringdown spectroscopy.

Cavity ringdown spectra of the A-X electronic transition of all eight isomers of the pentyl peroxy radical are reported. Using the corresponding assignments from previously studied smaller alkyl peroxy radicals, assignments of origin bands are made for the pentyl peroxy isomers including some conformer-specific assignments for bands of a given isomer. Ab initio calculations also were performed to aid in the spectral assignments for neopentyl, t-butyl, and t-pentyl peroxies.

The vibrationless A<--X transition of the jet-cooled deuterated methyl peroxy radical CD3O2 by cavity ringdown spectroscopy.

The nearly rotationally resolved spectrum of the A (2)A(')<--X (2)A(") 0(0)(0) transition of perdeutero methyl peroxy near 1.35 microm has been studied via pulsed cavity ringdown spectroscopy. Albeit, this is a weak transition, it is possible to observe the spectrum under jet-cooled conditions (approximately 15 K) by combining a source of narrow-bandwidth radiation (approximately 250 MHz) with a supersonic slit-jet expansion incorporating an electric discharge.