Understanding surface structure of graphene is important for its integration into composite materials. Here, we have used synchrotron X-ray reflectivity (XRR) to study the commercially available samples (prepared via chemical vapor deposition, and marketed as monolayers) on SiO2/Si at different temperatures. photoelectron spectroscopy, photoemission electron microscopy atomic force (AFM) were employed evaluate composition morphology layer. Our results indicate that characterized consisted...

Sodium carboxymethyl cellulose (Na CMC) is used for its thickening and swelling properties in a wide range of complex formulated products pharmaceutical, food, home, personal care applications, as well paper, water treatment, mineral processing industries. To design Na CMC solutions detailed understanding the concentration-dependent rheology relaxation response needed. We address this here by investigating aqueous over concentrations using static dynamic light scattering. The concentration...

We investigate the shape, dimensions, and transformation pathways of micelles linear sodium alkylbenzenesulfonate (NaLAS), a common anionic surfactant, in aqueous solution. Employing Small Angle Neutron Scattering (SANS) surface tensiometry, we quantify effects surfactant concentration (0.6-15 wt%), temperature (5-40 °C) added salt (≤0.35 M Na2SO4). Spherical form at low NaLAS (≤2.6 wt%) water, become elongated with increasing decreasing temperature. Addition reduces critical micelle (CMC)...

In complex colloidal systems, particle-poor regions can develop within particle-rich phases during sedimentation or creaming. These are overlooked by 1D profiles, which typically used to assess particle distributions in a sample. Alternative methods visualise and quantify these required better understand phase separation, is the focus of this paper. Magnetic resonance imaging has been monitor development compositional heterogeneity vesicle-polymer mixture undergoing T2 relaxation time maps...

The structure and flow behavior of a concentrated aqueous solution (45 wt %) the ubiquitous linear sodium alkylbenzenesulfonate (NaLAS) surfactant is investigated by microfluidic small-angle X-ray scattering (SAXS) at 70 °C. NaLAS an intrinsically complex mixture over 20 molecules, presenting coexisting micellar (L1) lamellar (Lα) phases. Novel devices were fabricated to ensure pressure thermal resistance, ability handle viscous fluids, low SAXS background. Polarized light optical microscopy...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoelectron spectrum, ionization potential, and heat of formation dichlorocarbeneDaniel W. Kohn, Eric S. J. Robles, Cameron F. Logan, Peter ChenCite this: Phys. Chem. 1993, 97, 19, 4936–4940Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1 1993https://pubs.acs.org/doi/10.1021/j100121a012https://doi.org/10.1021/j100121a012research-articleACS PublicationsRequest reuse permissionsArticle...

Erucamide is known to play a critical role in modifying polymer fiber surface chemistry and morphology. However, its effects on crystallinity mechanical properties remain be understood. Here, synchrotron nanofocused X-ray Diffraction (nXRD) revealed bimodal orientation of the constituent chains aligned along axis cross-section, respectively. promoted fiber, leading larger more numerous lamellae crystallites. The nXRD nanostructual characterization complemented by single-fiber uniaxial...

We investigate the structure and interactions of a model anionic/amphoteric mixed surfactant micellar system, namely, sodium dodecyl sulfate (SDS) N,N-dimethyldodecylamine N-oxide (DDAO), employing SANS, FTIR, DLS, pH measurements, in range 0.1–100 mM total concentration 0–100% DDAO. Increasing is found to elongate prolate ellipsoid micelles (RPolar ∼ 25–40 Å), accompanied by up 6-fold increase charge. The synergy, terms charge size, diffusion coefficient, solution pH, headgroup...

ZnCH3 and CdCH3 radicals have been prepared in a cold supersonic free jet expansion their laser-induced-fluorescence spectrum recorded for the à 2E←X̃ 2A1 electronic transition. These spectra show well resolved rotational spin structure, which has completely analyzed. This analysis yields constants components of spin–rotation tensors X̃ states both radicals. The observed are discussed terms structure It is demonstrated that upper F2 spin–orbit component 2E state strongly perturbed by...

We report the coupling of dynamic light scattering (DLS) in microfluidics, using a contact-free fibre-optic system, enabling under-flow characterisation range solutions, dispersions, and structured fluids.

We investigate the effect of micrometer-scale surface wrinkling on attachment and proliferation model bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli K12) fungi (Candida albicans). Specifically, sinusoidal (1D), checkerboard (C), herringbone (H) patterns were fabricated by mechanical plasma-oxidized polydimethylsiloxane (PDMS) bilayers contrasted with flat (F) surfaces. Microbial deformation orientation found to correlate aspect ratio commensurably pattern...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic spectroscopy of jet-cooled half-sandwich magnesium organometallic complexes MgC5H5, MgC5H4CH3, and MgC4H4NEric S. J. Robles, Andrew M. Ellis, Terry A. MillerCite this: Phys. Chem. 1992, 96, 22, 8791–8801Publication Date (Print):October 1, 1992Publication History Published online1 May 2002Published inissue 1 October 1992https://pubs.acs.org/doi/10.1021/j100201a021https://doi.org/10.1021/j100201a021research-articleACS PublicationsRequest...

We investigate the formation of poly(vinyl alcohol) microparticles by selective extraction aqueous polymer solution droplets, templated microfluidics and subsequently immersed in a non-solvent bath. The role molecular mass (18-105 kg mol-1), degree hydrolysis (88-99%) thus solubility, initial concentration (0.01-10% w/w) are quantified. Monodisperse droplets with radii ranging from 50 to 500 μm were produced at flow-focusing junction carrier phase hexadecane extracted into ethyl acetate....

Understanding the structure of polymer/surfactant mixtures at air-water interface is fundamental importance and also relevance to a variety practical applications. Here, complexation between neutral 'tardigrade' comb co-polymer (consisting hydrophilic polyethylene glycol backbone with hydrophobic polyvinyl acetate grafts, PEG-g-PVAc) an anionic surfactant (sodium dodecyl sulfate, SDS) has been studied. Contrast-matched neutron reflectivity (NR) complemented by surface tension measurements...

The crystallization mechanisms and kinetics of micellar sodium dodecyl sulfate (SDS) solutions in water, under isothermal conditions, were investigated experimentally by a combination reflection optical microscopy (OM), differential scanning calorimetry (DSC), attenuated total Fourier transform infrared spectroscopy (ATR-FTIR). rates nucleation growth estimated from OM DSC across temperatures ranging 20 to −6 °C for 20% SDS-H2O, as well 10 30% SDS-H2O at representative 6, 2, −2 °C. A...

A laser vaporization/photolysis technique for obtaining spectra of jet-cooled organometallic molecules is reported. It makes use an excimer which vaporizes a metal sample and simultaneously photolyzes organic precursor passing over the surface metal. The atoms fragments then react to yield species. In principle, this approach could be used prepare wide variety gas-phase compounds any spectroscopic study. To illustrate its capabilities, excitation monocyclopentadienide monomethyl derivatives...