Structural and elemental investigations of isolated aquatic humic substances using X-ray photoelectron spectroscopy

Bubert, H.; Lambert, Jörg; Burba, P.

doi:10.1007/s002160000492

Cited by 31 publications

(27 citation statements)

References 1 publication

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“…4c yielded the results we expected from an FA (Bubert et al 2000;Frimmel et al 2002), in particular the low carbon content, observable from the smaller peaks around 285-286 eV (9.27%) and the high π* C=O resonance at 288.1 eV (17.0%). Comparing the results in Figs.…”

Section: Environmental Samplessupporting

confidence: 84%

“…This has been proved by other authors with several other methods. The FA has also been studied using XPS (Bubert et al 2000). The peak assignments and also the way of calculating the elemental composition are in good accordance to the results reported here.…”

Section: Environmental Samplessupporting

confidence: 81%

“…The inset in a shows the structural formula of polyimide. The assignment of the peaks with increasing energy results from comparison with published results and the differentiation of the measured data, and is presented in Table 2 photoelectron spectroscopy) data (Bubert et al 2000). For the analysis, we hence assumed that the area under a Gaussian curve assigned to a resonance is proportional to the frequency of occurrence of this binding form of the studied element (Xia et al 1998;Huffman et al 1991;Cody et al 1998; di Stasio and Braun 2006), making it possible to approximate the composition of the bound elements.…”

Section: Reference Samplesmentioning

confidence: 99%

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Characterization of refractory organic substances by NEXAFS using a compact X-ray source

et al. 2011

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Purpose We present the characterization of environmental samples using near-edge X-ray absorption fine structure (NEXAFS) spectra recorded with an in-house device. We want to point out the feasibility of such an easily accessed complementary technique, if not sometimes alternative to NEXAFS studies performed with synchrotron radiation, as the number of compact setups is increasing. Materials and methods The experiments were carried out using a laser-driven plasma source. We studied heterogeneous samples like refractory organic substances to demonstrate the potential of NEXAFS spectra, achieved by such an instrument, concerning specimens of high chemical complexity.Results and discussion From the respective resonance peaks in the spectra, the presence of certain functional groups, such as aromatic or carbonyl groups, is verified, and the elemental composition is estimated. The results of the reference samples are consistent with the literature. For the environmental samples, external influences of the extraction solvent or fertilizers can be determined from the spectra. Conclusions This could provide the possibility to perform test experiments with samples, which are later studied in more detail with synchrotron light and might as well give an impulse on the broader spread of the application of NEXAFS spectroscopy.

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Section: Environmental Samplessupporting

confidence: 84%

Section: Environmental Samplessupporting

confidence: 81%

Section: Reference Samplesmentioning

confidence: 99%

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Characterization of refractory organic substances by NEXAFS using a compact X-ray source

et al. 2011

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“…The two main bands were assigned to carbonyl oxygen centered at 532 eV and ether oxygen centered at 533.5 eV. 32,60 It was clear that upon BMI incorporation, the carbonyl oxygen band increased and the ether oxygen decreased. This might be attributed to the presence of carbonyl oxygen in BMI but the presence of ether oxygen in PSF as shown in Table III.…”

Section: Xps Analysismentioning

confidence: 97%

“…For the purpose of comparison, the base line where there is no band was adjusted to be at the same level for all spectra in each figure. As shown in Figure 5, four bands could be observed that might be assigned to carbon bonded to another carbon or/ and hydrogen including aromatics centered at 285 eV, 59 carbon has a single bond with nitrogen or oxygen located between 286 and 287 eV 60,61 as in ether or alcohol, carbonyl carbon in imide group located between 288.5 eV and 288.8 eV, 59,62 and shake up satellite of phenyl groups from to * located between 290 and 294 eV. 32,63 The decrease in the first band at 285 eV upon BMI incorporation was attributed to lower concentration of this carbon type in BMI than in PSF as shown in Table III.…”

Section: Xps Analysismentioning

confidence: 99%

Synthesis and characterization of modified bismaleimide/polysulfone semi‐interpenetrating polymer networks

Kurdi

Kumar

2006

J of Applied Polymer Sci

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The present work reports a new method of preparing semi‐interpenetrating polymer network (semi‐IPN) membranes through in situ polymerization of bismaleimide (BMI) within polysulfone (PSF). It was found that BMI could be polymerized at ambient conditions in the presence of a proton donor and PSF without the use of an initiator or a catalyst. Chemical structure characterization of these semi‐IPNs by Fourier transform infrared attenuated total reflection (FTIR‐ATR) revealed the possibility of imide cleavage and formation of amic acid when BMI polymerization was continued for a longer time while X‐ray photoelectron spectroscopy (XPS) revealed the protonation of imide nitrogen at shorter polymerization time. It was also found that size of thermoset BMI phase within the PSF thermoplastic has a significant impact on glass‐transition temperature of resulting semi‐IPN. By controlling the thermoset/thermoplastic phase separation of semi‐IPNs through dope composition and formation techniques, gas separation membranes with comparable selectivity and permeance that were up to 12 times higher than corresponding PSF membranes were formed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 369–379, 2006

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Development of sample preparation technique to characterize chemical structure of humin by synchrotron‐radiation–based X‐ray photoelectron spectroscopy

Pham

Miyata

Awata

et al. 2018

Surface & Interface Analysis

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Carbon-binding state of humin (HM, a non-conductive insoluble organo-mineral humic substance) was successfully characterized for the first time by synchrotronradiation-based X-ray photoelectron spectroscopy (XPS). Four sample preparation techniques-HM on double-sided carbon tape, indium sheet, copper mesh, and in pellet formed from the mixture of HM and copper powder (Cu) at different mixing ratios (1:1, 1:2, and 1:6 v/v)-were compared. The results show that HM samples prepared using the first three methods had significant charge buildup, which made the interpretation of the XPS spectra impossible because of the shifts in the binding energy of C 1s XPS spectra. Pellets of HM:Cu mixture enhanced the electrical conductivity and reduced charge buildup on the sample surface. Pellets prepared with HM:Cu ratio of 1:1 (v/v) provided the minimum charge buildup and high sensitivity with difference in C 1s spectra regardless of the observing position. The C 1s spectra, estimated by the subtraction of the carbon contamination in Cu, showed the resolution of C¼C (284.0 eV), C-C/C-H (285.1 eV), C-O (286.3 eV), C¼O (287.3 eV), and O¼C-O (288.3 eV) and three additional peaks of CF (289.3 eV), CF 2 (290.2 eV), and CF 3 (291.4 eV). Soft X-ray absorption spectroscopic (XAS) analysis further proved the existence of fluoride (F 1s) in HM structure. The detection of fluorinated carbon in HM showed a great advancement of XPS compared with other conventionalanalyses. X-ray with the incident angle of 0°provided the smallest (nearly negligible) energy shift in the C 1s spectra of HM and did not damage the surface of the sample.

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Structural and elemental investigations of isolated aquatic humic substances using X-ray photoelectron spectroscopy

Cited by 31 publications

References 1 publication

Characterization of refractory organic substances by NEXAFS using a compact X-ray source

Characterization of refractory organic substances by NEXAFS using a compact X-ray source

Synthesis and characterization of modified bismaleimide/polysulfone semi‐interpenetrating polymer networks

Development of sample preparation technique to characterize chemical structure of humin by synchrotron‐radiation–based X‐ray photoelectron spectroscopy

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