Surface radical analysis on plasma-treated polymers

Wilken, Ralph; Holländer, Andreas; Behnisch, J.

doi:10.1016/s0257-8972(99)00282-0

Cited by 59 publications

(56 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[7][8][9][10] Since the high energy ($6 to greater than 10 eV) of photons in the VUV spectral range exceeds covalent chemical bond energies found in most polymers ( 5 eV), [11] absorption of the VUV radiation results in bond scission and in the formation of either alkyl or allyl free radicals or both. [12][13][14][15] These can then further react with reactive species in the neighbouring gas phase [16,17] or with one another forming either new chemical functionalities or C C bonds (unsaturation) or both at the polymer surface or a cross-linked network below the surface. [12,14,15,18] VUV photolysis of polymers has been reported extensively in the literature: mass spectrometry [5,12,19,20] and quartz crystal microbalance (QCM) measurements [4,21,22] bear witness to material ablation, whereas infrared spectroscopy (IR), [21,22] radical trapping, [14,15,22] and electron spin resonance (ESR) analysis [13,23] on VUV-irradiated polymer surfaces demonstrated the formation of C C bonds and of radicals.…”

Section: Introductionmentioning

confidence: 99%

“…[12][13][14][15] These can then further react with reactive species in the neighbouring gas phase [16,17] or with one another forming either new chemical functionalities or C C bonds (unsaturation) or both at the polymer surface or a cross-linked network below the surface. [12,14,15,18] VUV photolysis of polymers has been reported extensively in the literature: mass spectrometry [5,12,19,20] and quartz crystal microbalance (QCM) measurements [4,21,22] bear witness to material ablation, whereas infrared spectroscopy (IR), [21,22] radical trapping, [14,15,22] and electron spin resonance (ESR) analysis [13,23] on VUV-irradiated polymer surfaces demonstrated the formation of C C bonds and of radicals. However, almost all of these investigations were carried out with Summary: The wavelength-dependent vacuum ultraviolet (VUV) photolysis of several polymers, low density polyethylene (LDPE), biaxially oriented poly(propylene) (BOPP), atactic polystyrene (PS), and poly(methyl methacrylate) (PMMA), was studied by irradiation in vacuum with the wellcharacterized emissions from four different resonant or excimer VUV sources.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Vacuum Ultraviolet Photolysis of Hydrocarbon Polymers

Truica-Marasescu

Wertheimer

2005

Macro Chemistry & Physics

108

131

View full text Add to dashboard Cite

Summary: The wavelength‐dependent vacuum ultraviolet (VUV) photolysis of several polymers, low density polyethylene (LDPE), biaxially oriented poly(propylene) (BOPP), atactic polystyrene (PS), and poly(methyl methacrylate) (PMMA), was studied by irradiation in vacuum with the well‐characterized emissions from four different resonant or excimer VUV sources. These lamps comprise radiofrequency (r.f.) discharges in different noble gases, such as krypton, xenon (at low pressures, producing near‐monochromatic resonant line radiations), xenon excimer (at “high” pressure), and a deuterium/argon mixture (producing a broad‐band emission). VUV‐induced mass loss (ablation or etching) was monitored in situ by quartz crystal microbalance measurements. Following irradiation, samples were analysed by ATR‐FTIR and XPS, to evaluate near‐surface structural changes (e.g., creation of unsaturation, cross‐linking) resulting from the VUV‐initiated bond scissions and radical‐creation reactions. PMMA was the most readily ablatable polymer, whereas the mass loss of BOPP was higher than that of LDPE, regardless of the irradiation wavelength, λ. All polymers were found to form double bonds, with the exception of PS, which is rather stable, probably due to energy dissipation by fluorescence.Formation of double bonds in a) vinyl‐, b) vinylidene‐, and c) vinylene‐like unsaturated groups, as a function of the radiation dose, D, for KrL (▪), XeL (▴), and D2Ar‐irradiated (•) PMMA.magnified imageFormation of double bonds in a) vinyl‐, b) vinylidene‐, and c) vinylene‐like unsaturated groups, as a function of the radiation dose, D, for KrL (▪), XeL (▴), and D2Ar‐irradiated (•) PMMA.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Vacuum Ultraviolet Photolysis of Hydrocarbon Polymers

Truica-Marasescu

Wertheimer

2005

Macro Chemistry & Physics

108

131

View full text Add to dashboard Cite

show abstract

“…The signal assigned to the open form of N-C pyrrolic ring at 401.7 eV [47], and new signals at 402. 7 eV corresponding to -C=N-OH, at 403.8 eV assigned to -C-N=O group can be identified [43,48,49]. The analysis of both C and N 1s core signals before and after degradation confirmed irreversible changes in the carbon structure.…”

Section: Electrochemical Stabilitymentioning

confidence: 80%

Electrochemical stability of the polymer-derived nitrogen-doped carbon: an elusive goal?

Cong

Radtke

Stumpf

et al. 2015

Mater Renew Sustain Energy

View full text Add to dashboard Cite

Nitrogen-doped carbon is a promising metalfree catalyst for oxygen reduction reaction in fuel cells and metal-air batteries. However, its practical application necessitates a significant cost reduction, which can be achieved in part by using new synthetic methods and improvement of catalytic activity by increasing the density of redox active centers. This can be modulated by using polymer as the carbon and nitrogen sources. Although, superior catalytic activity of such N-doped C has been investigated in details, the electrochemical long-term stability of polymer-derived doped-carbon is still unclear. Herein, in this study we generated N-doped carbon from the most recommended polymer that is comparable to the state-of-the-art materials with porosity as high as 2,086 m 2 g -1 and a nitrogen doping level of 3-4 at.%, of which 56 % is pyrrolic N, 36.1 % pyridinic and *8 % graphitic. The electrochemical characterization shows that N-doped carbon is catalytic toward oxygen reduction in an alkaline electrolyte via a favorable four-electron process, however, not stable under long-term potential scanning. The irreversible electrochemical oxidation of this material is associated with the presence of a significant content or pyrrolic and pyridinic N close to the edge of the carbon network originating from the polypyrrole precursor. These structures are less stable under operating electrochemical potential. The role of polypyrrole as the precursor of N-doped carbons has to be carefully revised since it supplies sufficient number of catalytic sites, but also generates unstable functionalities on the carbon surface.

show abstract

“…Especially dielectric barrier discharge (DBD) plasmas, i.e., the electrical discharges between two electrodes separated by an insulating dielectric barrier that typically operate at elevated pressure (e.g., atmospheric pressure) and cold gaseous plasmas, i.e., glow discharges at low pressure in a vacuum system, are used for modifying fibers and textiles as potential eco-friendly and energy-saving alternatives to some existing chemical processes. They can modify the surface nature of hydrophobic polymers without remarkable deterioration to their bulk properties by etching and polarization of the polymers [24][25][26]. Similarly, it is assumed that these actions might destroy the hydrophobic cuticle of the cotton fiber, thus resulting in high accessibility of pectinases to pectic substances on the cotton surfaces and enhancing bioscouring effectiveness of cotton fabrics [8].…”

Section: Introductionmentioning

confidence: 99%

Plasma-Aided Cotton Bioscouring: Dielectric Barrier Discharge Versus Low-Pressure Oxygen Plasma

Wang

Fan

Cui

et al. 2009

Plasma Chem Plasma Process

View full text Add to dashboard Cite

The hydrophobic cuticle of the cotton fiber has formed a natural barrier for pectinase to catalyze its substrates (pectins beneath the cuticle), thus resulting in an insufficient scouring for cotton. Two plasma-based treatments, dielectric barrier discharge (DBD) at atmospheric pressure and cold oxygen plasma at low pressure in a vacuum system, were used as the pretreatments prior to cotton bioscouring, aiming at increasing the accessibility of pectinases to the pectic substances on the cotton fiber. The effects of different processing parameters of DBD and oxygen plasmas on the wettability, whiteness and burst strength of pectinase-scoured cotton were determined and compared. Although both of the pretreatments could enhance cotton bioscouring, DBD might be more suitable for current bioscouring due to its continuous processing mode and lower requirements to the equipment.

show abstract

Surface radical analysis on plasma-treated polymers

Cited by 59 publications

References 9 publications

Vacuum Ultraviolet Photolysis of Hydrocarbon Polymers

Vacuum Ultraviolet Photolysis of Hydrocarbon Polymers

Electrochemical stability of the polymer-derived nitrogen-doped carbon: an elusive goal?

Plasma-Aided Cotton Bioscouring: Dielectric Barrier Discharge Versus Low-Pressure Oxygen Plasma

Contact Info

Product

Resources

About