Reproducible XPS on biopolymers: cellulose studies

Johansson, Leena‐Sisko; Campbell, J.M.

doi:10.1002/sia.1827

Cited by 251 publications

(238 citation statements)

References 5 publications

Supporting

Mentioning

221

Contrasting

Unclassified

Order By: Relevance

“…The pump was then stopped and started again (0.1 mL/min) after 3 h (4 h in the case of EG I) of treatment to rinse the system with buffer solution. All measurements were recorded at 5 MHz fundamental resonance frequency and its overtones corresponding to 15,25,35,55, and 75 MHz. The third overtone (15 MHz) was used for data processing.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Preferential Adsorption and Activity of Monocomponent Cellulases on Lignocellulose Thin Films with Varying Lignin Content

et al. 2013

Self Cite

View full text Add to dashboard Cite

Understanding the enzymatic hydrolysis of cellulose and the influence of lignin in the process are critical for viable production of fuels and chemicals from lignocellulosic biomass. The interactions of monocomponent cellulases with cellulose and lignin substrates were investigated by using thin films supported on quartz crystal microgravimetry (QCM) resonators. Trichoderma reesei exoglucanase (CBH-I) and endoglucanase (EG-I) bound strongly to both cellulose and lignin but EG-I exhibited a distinctive higher affinity with lignin, causing a more extensive inhibition of the cellulolytic reactions. CBH-I was found to penetrate into the bulk of the cellulose substrate increasing the extent of hydrolysis and film deconstruction. In the absence of a cellulose binding domain (CBD) and a linker, the CBH-I core adsorbed slowly and was not able to penetrate into the film. Conversely to CBH-I, EG-I exhibited activity only on the surface of the lignocellulose substrate even when containing a CBD and a linker. Interestingly, EG-I displayed a clearly different interaction profile as a function of contact time registered by QCM.

show abstract

Section: ■ Experimental Sectionmentioning

confidence: 99%

Preferential Adsorption and Activity of Monocomponent Cellulases on Lignocellulose Thin Films with Varying Lignin Content

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…The power applied to the X-ray anode was reduced to 90 W to avoid sample degradation. 7,8 The instrument work function was calibrated to give a BE of 83.96 eV for the Au 4f 7/2 line for metallic gold. The samples were then kept under vacuum overnight prior to analyses.…”

Section: Xps Analysismentioning

confidence: 99%

XPS characterization of wood chemical composition after heat-treatment

Inari¹,

Pétrissans²,

Lambert

et al. 2006

Surf. Interface Anal.

157

View full text Add to dashboard Cite

XPS was used to characterize the chemical changes occurring after drying or applying a heat-treatment to beech wood samples. Our results indicate that the surface of this air-exposed material could be strongly affected either by the ambient atmosphere during storage or by the complex atmosphere in the oven during drying or heat-treatment. However, the O/C ratio measured after removal of a thin slice of a few millimetres of an untreated sample is in reasonable agreement with that calculated from the wellestablished chemical composition of beech. Through this methodology (equivalent to scraping for hard materials) it is expected to get a realistic characterization of the wood. The reliability and repeatability of the XPS measurements have been checked and the method applied to the study of the chemical changes of the beech samples subjected to heat-treatment. Heating at 240°C induces a significant decrease of the O/C ratio from 0.55 before to 0.44 after the treatment. Heat-treatment induces also a decrease of the C 2 carbon contribution (carbon atom bound to a single non-carbonyl oxygen) associated with an increase of the C 1 carbon contribution (carbon atoms bound only to carbon or hydrogen atoms), in agreement with chemical modifications reported previously in the literature. Thanks to the small analysed area of the equipment used in this study, different spots were analysed to demonstrate the presence or absence of a gradient of chemical composition due to thermal degradation or migration of extractives from within the wood structure to its surface. At the scale of our observations, the different wood samples investigated (dried or heat treated) appear to be homogeneous.

show abstract

“…A fresh piece of 100% cellulose was measured with each sample batch, as an in-situ reference. [58] Elemental surface compositions were determined from low resolution survey spectra (1 eV step, 80 eV CAE), while the high resolution regional data of C 1s, O 1s, Cl 2p and N 1s were used in detailed chemical analysis (0.1 eV step, 20 eV CAE). The aliphatic component in high resolution C 1s peak at 285.0 eV was utilized as the binding energy reference for all spectra.…”

Section: Methodsmentioning

confidence: 99%

Maskless, High‐Precision, Persistent, and Extreme Wetting‐Contrast Patterning in an Environmental Scanning Electron Microscope

Liimatainen

Shah

Johansson

et al. 2016

Small

Self Cite

View full text Add to dashboard Cite

1 This is the pre-peer reviewed version of the following article:Liimatainen, V., Shah, A., Johansson, L.-S., Houbenov, N. and Zhou, Q. (2016), Maskless, High-Precision, Persistent, and Extreme Wetting-Contrast Patterning in an Environmental Scanning Electron Microscope. Small. doi:10.1002/smll.201503127, which Since the past decade, micro-and nanopatterns with high wetting contrast for water have been reported on natural [1,2] and man-made [3,4] surfaces. Such patterns have found uses in a diverse set of applications, including water collection from humid air mimicking desert beetles; [5] enhancing boiling heat transfer; [6] microelectromechanical systems (MEMS) assembly using surface tension-driven self-alignment; [7] arranging nanostructures in ordered arrays [8] for 2 nanophotonic devices e.g. antennas, filters and optical processing circuits; [9] transport of both droplets [10] and liquid flows [11] for lab-on-a-chip devices; and solving cross-contamination and cell migration problems in ultrahigh-density living cell microarrays. [12] Many highly successful methods utilizing well-developed technologies have been employed to produce those micro and nanoscale wetting features, from conventional photolithographic methods, laser interference lithography, [13,14] electron beam lithography (EBL), [15,16] to near-field scanning optical microscopy (NSOM), [17,18] microcontact printing (µCP) [19,20] and pulsed laser beams; [21,22] however, these techniques also have their limitations. For example, in conventional photolithography, sub-µm resolution requires expensive equipment and the wet processing steps may damage the often delicate surface structure of superhydrophobic substrates; laser interference lithography can only produce features in the shape of a few types of interference patterns; microcontact printing techniques use a stamping process that is challenging to apply on rough surfaces; [23] focused, pulsed laser beams have a resolution of few µm, limited by the beam spot size; and specific, photo-or electron sensitive materials are required for NSOM and EBL. The pursuit for an effective method of fabricating highresolution wetting patterns with extreme wetting contrast is still ongoing.One potential solution is direct electron beam writing, where the beam modifies the surface directly without any pattern-transferring layer or further processing steps. In previous works, the effect of electron beams on surface wetting properties has been studied; e.g. high-energy electron beams (> 500 keV) can tune the wettability of poly(ethylene terephthalate) (PET) films, [24] poly-l-lactic acid (PLLA), [25] rubber [26] and textile fabrics, [27] where the maximum changes in water contact angles varied from 15° to 32°; and low-energy electron beams (< 0.5 keV) [28,29] can increase the water contact angle by 71° on a silicon dioxide surface, and by 25° on a zinc oxide nanomaterial. In the aforementioned works, electron beam has not been controlled to produce wetting patterns in specific shapes on the surface. 3In this p...

show abstract

Reproducible XPS on biopolymers: cellulose studies

Cited by 251 publications

References 5 publications

Preferential Adsorption and Activity of Monocomponent Cellulases on Lignocellulose Thin Films with Varying Lignin Content

Preferential Adsorption and Activity of Monocomponent Cellulases on Lignocellulose Thin Films with Varying Lignin Content

XPS characterization of wood chemical composition after heat-treatment

Maskless, High‐Precision, Persistent, and Extreme Wetting‐Contrast Patterning in an Environmental Scanning Electron Microscope

Contact Info

Product

Resources

About