XPS and atomic force microscopy of plasma‐treated polysulfone

Hopkins, Janet; Badyal, J. P. S.

doi:10.1002/(sici)1099-0518(199606)34:8<1385::aid-pola1>3.0.co;2-#

Cited by 34 publications

(28 citation statements)

References 44 publications

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“…In the case of sulfur at least two new signals appear in the core-level spectra with binding energies of 168.8 and 169.3 eV (Figure 4 a). [30][31][32] The intensity ratio between oxidized and unoxidized components was determined by peak fitting of the XPS signal, assuming the same peak shape for all components. [30][31][32] The intensity ratio between oxidized and unoxidized components was determined by peak fitting of the XPS signal, assuming the same peak shape for all components.…”

Section: Product Evolution Studied By Xpsmentioning

confidence: 99%

Photodegradation of C‐PCPDTBT and Si‐PCPDTBT: Influence of the Bridging Atom on the Stability of a Low‐Band‐Gap Polymer for Solar Cell Application

et al. 2014

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The kinetics of photodegradation and the reactivity of different sites of the low-band-gap polymers poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (C-PCPDTBT) and poly[2,6-(4,4-bis-(2-ethylhexyl)dithieno[3,2-b:2',3'-d]silole)-alt-4,7-(2,1,3-benzothiadiazole)] (Si-PCPDTBT) are investigated as thin films and are compared to those of poly(3-hexylthiophene) (P3HT). The decay kinetics are monitored with UV/Vis spectroscopy and the reactivity and product evolution are investigated with X-ray photoelectron spectroscopy (XPS). Both polymers exhibit higher stability than P3HT. The bridging atom in the cyclopentadithiophene (CPDT) subunit has a significant influence on the stability. Varying oxidation rates for the different elements were observed. In the case of Si-PCPDTBT, the silicon atom is oxidized primarily, whereas the photooxidation rates of the other elements are reduced relative to C-PCPDTBT. Additionally, XPS experiments with varying excitation energies reveal a significant reaction gradient within a few nanometers of the surface of degraded thin films of C-PCPDTBT.

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Section: Product Evolution Studied By Xpsmentioning

confidence: 99%

Photodegradation of C‐PCPDTBT and Si‐PCPDTBT: Influence of the Bridging Atom on the Stability of a Low‐Band‐Gap Polymer for Solar Cell Application

et al. 2014

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“…[5][6][7][8][9][10][11][12][13] AFM is especially suited to polymer analysis due to the low applied forces in contact mode, which can be further reduced by using tapping mode. These low forces allow the film surface to be imaged without modification by the force of the AFM tip on the surface.…”

Section: Introductionmentioning

confidence: 99%

Surface morphology of PECVD fluorocarbon thin films from hexafluoropropylene oxide, 1,1,2,2-tetrafluoroethane, and difluoromethane

Labelle

Gleason

1999

J. Appl. Polym. Sci.

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Atomic force microscopy (AFM) measurements have been made on a series of fluorocarbon films deposited from pulsed plasmas of hexafluoropropylene oxide (HFPO), 1,1,2,2-tetrafluoroethane (C 2 H 2 F 4 ), and difluoromethane (CH 2 F 2 ). All of the films give images showing nodular growth (cauliflower-like appearance), with the size and distribution of the nodules dependent on both the precursor, the degree of surface modification to which the growing film is exposed, and the substrate surface. Films deposited from C 2 H 2 F 4 showed clusters of smaller nodules around larger nodules, whereas films deposited from CH 2 F 2 were characterized by a uniform distribution of smaller nodules, and films deposited from HFPO had the largest observed nodules. Movchan and Demchishin's structure zone model was applied to the observed films, which were all found to be zone 1 structures, indicating that film growth is dominated by shadowing effects. Increased substrate temperature and incident power per nm of film deposited results in decreased rms roughness, consistent with greater atomic mobility during deposition. Larger nodules in the fluorocarbon films developed on silicon wafer substrates than on rougher Al-coated substrates. Advancing contact angles for all of the films were found to be higher than that of PTFE (108°), indicating both hydrophobic and rough surfaces. Specifically, contact angles of films deposited from HFPO were found to increase with pulse off-time, the same trend observed for both the CF 2 fraction of the film and the rms roughness.

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“…6a and b, respectively) core level XPS spectra. 61 The percentage enhancement in the area under the curve for the peak of 531.3 eV from Ps UF to Ps-nRGO UF-2 is 5.01%. But, there is a percentage decline in the concerned peak area by 4.77%, from Ps UF to Ps-nRGO UF-2 ( Table 2).…”

Section: Resultsmentioning

confidence: 99%

Reinforcement of nanostructured reduced graphene oxide: a facile approach to develop high-performance nanocomposite ultrafiltration membranes minimizing the trade-off between flux and selectivity

et al. 2015

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The salient features of a nanostructured carbonaceous material like graphene or graphene oxide have provided innovative alternatives for the development of nanocomposite membranes with better selectivity without having a compromise in throughput, which as a result have a promising role to play in desalination and water purification. Here, nanostructured reduced graphene oxide (nRGO) is synthesized from graphite powder and characterized. Using non-solvent induced phase inversion technique, a series of nanocomposite ultrafiltration (UF) membranes are developed by in situ impregnation of the as synthesized nRGO in polysulfone (Ps) polymer matrix with variation of nRGO from 1 to 8 w/w%. The physicochemical features and transport properties offered by the membranes are evaluated. Structural characterization of the Ps-nRGO composite UF membranes is done by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The variation in porous morphology of the membranes upon impregnation of nRGO is evaluated by scanning electron microscopy. Variation in skin surface topography is analyzed by atomic force microscopy. The change in surface hydrophilicity is evaluated by contact angle studies. The thermal and mechanical properties of the membranes are assessed by thermogravimetric analysis and tensile strength measurements, respectively. The studies reveal that an optimum loading of nRGO (2 w/w%) in the Ps matrix resulted in membranes with elimination of the trade-off between the flux and selectivity that exists with the conventional UF membranes. In addition, the optimum loading of nRGO resulted in membranes with improved thermal and mechanical stability. Thus, nRGO as an emerging potential nanofiller can lead to the development of an ideal membrane with desirable attributes.

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XPS and atomic force microscopy of plasma‐treated polysulfone

Cited by 34 publications

References 44 publications

Photodegradation of C‐PCPDTBT and Si‐PCPDTBT: Influence of the Bridging Atom on the Stability of a Low‐Band‐Gap Polymer for Solar Cell Application

Photodegradation of C‐PCPDTBT and Si‐PCPDTBT: Influence of the Bridging Atom on the Stability of a Low‐Band‐Gap Polymer for Solar Cell Application

Surface morphology of PECVD fluorocarbon thin films from hexafluoropropylene oxide, 1,1,2,2-tetrafluoroethane, and difluoromethane

Reinforcement of nanostructured reduced graphene oxide: a facile approach to develop high-performance nanocomposite ultrafiltration membranes minimizing the trade-off between flux and selectivity

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