Construction and surface/interface behavior of bio-functional surface layer by microwave-excited Ar/H2O plasma-induced polyethylene glycol polymerization

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744093
Author(s):  
Z. Shao ◽  
A. Ogino ◽  
M. Nagatsu
Keyword(s):  
Surface Layer ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Optical Emission ◽  
Aging Effect ◽  
Hydroxyl Groups ◽  
Functional Surface ◽  
Interface Behavior ◽  
Water Contact ◽  
Spacer Layer

Ar/H2O microwave-excited surface-wave plasma-induced grafting-polymerization and crosslinking technique was presented to construct a bio-functional surface layer. Optical emission spectroscopy was used to diagnose Ar/H[Formula: see text]O plasma. The surface/interface behavior especially the aging effect of hydroxyl groups over the grafted PEG spacer layer was investigated by measuring water contact angle and X-ray photoelectron spectroscopy. The results demonstrate that the addition of water vapor into Ar plasma can optimize the concentration of hydroxyl functional groups on surface; grafted PEG spacer layer can provide a long-term hydrophilicity of PU films, and alleviate the aging effect of hydroxyl functional groups.

Preparation and Characterization of Plasma-Treated Porous Poly(glycerol sebacate) Scaffolds

2013 ◽  
Vol 747 ◽  
pp. 182-185
Author(s):  
Tharinee Theerathanagorn ◽  
Boonlom Thavornyutikarn ◽  
Wanida Janvikul
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Average Molecular Weight ◽  
Sebacic Acid ◽  
Angle Measurement ◽  
Porous Scaffolds ◽  
Hydroxyl Groups ◽  
Condensation Polymerization ◽  
Water Contact

In this study, poly (glycerol sebacate) (PGS) was initially synthesized via condensation polymerization of glycerol and sebacic acid at equimolar ratio (1:1) at 130°C for 24 h. The number average molecular weight (Mn) of the resulting polymer determined by gel permeation chromatography (GPC) was about 2800 g/mol. Porous PGS scaffolds were subsequently prepared by a particle-leaching technique. NaCl was added into the polymer at 60-90% w/w; the mixtures were cured in Teflon molds at 140°C for 16 h. The porous scaffolds were further subjected to surface treatment with low pressure oxygen plasma to increase surface carboxyl and hydroxyl groups and thereby enhance hydrophilicity of PGS scaffold surface. The surface morphology and wettability of both untreated PGS and plasma-treated PGS scaffolds were comparatively determined by scanning electron microscopy (SEM) and water contact angle measurement, respectively. A considerable decrease in water contact angle was observed on the PGS scaffolds after the plasma treatment. The surface chemistry, mechanical strength and degree of swelling of the PGS scaffolds were also assessed by X-ray photoelectron spectroscopy (XPS), dynamic mechanical analysis (DMA) and swelling measurement, respectively.

Fabrication and Characterization of Lanthanum Treated Carboxyl-Graphene Oxide Self-Assembled Composite Film on Silicon Substrate

2016 ◽  
Vol 693 ◽  
pp. 566-575 ◽  
Author(s):  
Da Shu ◽  
Hong Gao ◽  
Da Bin Zhang
Keyword(s):  
Graphene Oxide ◽  
Silicon Substrate ◽  
Photoelectron Spectroscopy ◽  
Multilayer Film ◽  
Film Surface ◽  
Chloroacetic Acid ◽  
Chemical Compositions ◽  
Hydroxyl Groups ◽  
Water Contact ◽  
Micro Electro Mechanical Systems

The admixture of graphene oxide (GO) sheets and chloroacetic acid were ultrasonic treated. As a result, epoxy and hydroxyl groups which existed onto GO sheets were transformed into carboxyl groups. Then, the carboxyl-GO sheets were assembled on silicon substrate by taking use of 3-aminopropyltriethoxysilane (APS) as an intermediate coupling agent (marked as APS-GO). Furthermore, La elements were deposited on the APS-GO by means of chemisorption to form multilayer film (APS-GO-La). Chemical compositions, surface morphologies, and microstructures were investigated by using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and water contact angle (WCA). Experimental results suggested that carboxyl-GO sheets distributed homogeneously on Si substrate. Results also indicated that lanthanum elements can react with the-COOH functional groups of GO film and be adsorbed on the APS-GO film surface. The prepared APS-GO-La multilayer film showed low surface free energy, which has potential applications in nano/micro electro-mechanical systems (N/MEMS).

scholarly journals The Use of Lanthanum Ions and Chitosan for Boron Elimination from Aqueous Solutions

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 718 ◽  
Author(s):  
Joanna Kluczka ◽  
Gabriela Dudek ◽  
Alicja Kazek-Kęsik ◽  
Małgorzata Gnus ◽  
Maciej Krzywiecki ◽  
...  
Keyword(s):  
Boric Acid ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
High Performance ◽  
Essential Element ◽  
Optical Emission ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Lanthanum Hydroxide ◽  
X Ray

Boron is an essential element for plants and living organisms; however, it can be harmful if its concentration in the environment is too high. In this paper, lanthanum(III) ions were introduced to the structure of chitosan via an encapsulation technique and the obtained hydrogel (La-CTS) was used for the elimination of the excess of B(III) from modelling solutions. The reaction between boric acid and hydroxyl groups bound to the lanthanum coordinated by chitosan active centres was the preponderant mechanism of the bio-adsorption removal process. The results demonstrated that La-CTS removed boric acid from the aqueous solution more efficiently than either lanthanum hydroxide or native chitosan hydrogel, respectively. When the initial boron concentration was 100 mg/dm3, the maximum adsorption capacity of 11.1 ± 0.3 mg/g was achieved at pH 5 and the adsorption time of 24 h. The successful introduction of La(III) ions to the chitosan backbone was confirmed by Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy, Fourier-Transform Infrared Spectroscopy, X-Ray Diffraction, X-ray Photoelectron Spectroscopy, and Inductively Coupled Plasma Optical Emission Spectroscopy. Due to its high-performance boron adsorption-desorption cycle and convenient form, La-CTS seems to be a promising bio-adsorbent for water treatment.

scholarly journals Layered Double Hydroxide Clusters as Precursors of Novel Multifunctional Layers: A Bottom-Up Approach

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 328 ◽  
Author(s):  
Cristina S. Neves ◽  
Alexandre C. Bastos ◽  
Andrei N. Salak ◽  
Maksim Starykevich ◽  
Daisy Rocha ◽  
...  
Keyword(s):  
Layered Double Hydroxide ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Optical Emission ◽  
Localized Corrosion ◽  
Emission Spectrometry ◽  
Water Contact ◽  
X Ray ◽  
Xrd Diffraction ◽  
Double Hydroxide

The specific microstructure of aluminum alloys is herein explored to grow spatially-resolved layered double hydroxide (SR-LDH) clusters on their surface. Upon chemical modification of LDHs via intercalation, adsorption and grafting with different functional molecules, novel surface-engineered surfaces were obtained. Crystal structure and phase composition were analyzed by X-ray diffraction (XRD) and surface morphology was observed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) and glow discharge optical emission spectrometry (GDOES) were used to correlate structural changes upon ion-exchange and interfacial modifications with chemical composition and surface profiles of the SR-LDH films, respectively. The protection conferred by these films against localized corrosion was investigated at microscale using the scanning vibrating electrode technique (SVET). LDH-NO3 phase was obtained by direct growth onto AA2024 surface, as evidenced by (003) and (006) XRD diffraction reflections. After anion exchange of nitrate with 2-mercaptobenzothiazole (MBT) there was a decrease in the SR-LDH thickness inferred from GDOES profiles. The subsequent surface functionalization with HTMS was confirmed by the presence of Si signal in XPS and GDOES analyses, leading to an increase in the water contact angle (c.a 144° ± 3°). SVET measurements of the SR-LDH films revealed exceptional corrosion resistance, whereas the bioluminescent bacteria assay proved the anti-microbial character of the obtained films. Overall the results obtained show an effective corrosion protection of the SR-LDHs when compared to the bare substrate and the potential of these films for biofouling applications as new Cr-free pre-treatments.

scholarly journals Effect of VUV Radiation on Surface Modification of Polystyrene Exposed to Atmospheric Pressure Plasma Jet

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1136 ◽  
Author(s):  
Rok Zaplotnik ◽  
Alenka Vesel
Keyword(s):  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Polymer Surface ◽  
Argon Plasma ◽  
Plasma Jet ◽  
Contact Angles ◽  
Surface Wettability ◽  
Water Contact ◽  
Xps Spectra ◽  
Sharp Interfaces

Precise tailoring of surface properties by gaseous plasma treatments remains a key scientific challenge, especially when adequate surface wettability should be laterally distributed, and sharp interfaces between hydrophobic and hydrophilic areas are desirable. The evolution of surface wettability and functional groups on polystyrene (PS) upon treatment with argon plasma jet was monitored by water contact angles and X-ray photoelectron spectroscopy (XPS). An array of water droplets was deposited on PS samples treated either directly by the plasma jet or only VUV radiation arising from the plasma. Rather sharp interfaces between the activated and not-affected regions were observed in both cases. The functionalization with highly-oxidized carbon functional groups, as determined by high-resolution C1s XPS spectra, was by far more efficient using the VUV radiation only. In contrast, the optimal wettability was achieved using direct plasma treatment. The results were explained by different mechanisms involved in the interaction of radiation and reactive plasma species with the polymer surface.

Proton Conductivity of Graphene Oxide on Aging

2017 ◽  
Vol 70 (5) ◽  
pp. 642 ◽  
Author(s):  
Mohammad Razaul Karim ◽  
Md. Saidul Islam ◽  
Nurun Nahar Rabin ◽  
Ryo Ohtani ◽  
Masaaki Nakamura ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Functional Groups ◽  
Proton Conductivity ◽  
Photoelectron Spectroscopy ◽  
Aging Effect ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Pxrd Pattern ◽  
X Ray ◽  
Oxygenated Functional Groups

The aging effect on the proton conductivity of graphene oxide (GO) is investigated. Characterizations of oxygenated functional groups and measurement of the proton conductivity have been performed using freshly prepared GO and the same sample after preserving for three years under ambient conditions. Although GO retains its layered structure, a slight deviation in its powder X-ray diffraction (PXRD) pattern and Raman spectra upon aging implies some changes in the interlayer distance and functional groups. Decomposition of epoxy groups on aging has been recognised by X-ray photoelectron spectroscopy (XPS) analysis. The proton conductivity was found to be reduced by 25 % after three years of aging.

scholarly journals Femtosecond Laser Produced Hydrophobic Hierarchical Structures on Additive Manufacturing Parts

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 601 ◽  
Author(s):  
Lishi Jiao ◽  
Zhong Chua ◽  
Seung Moon ◽  
Jie Song ◽  
Guijun Bi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Photoelectron Spectroscopy ◽  
Hierarchical Structures ◽  
Hydrophobic Surface ◽  
Functional Surface ◽  
Sem Images ◽  
Water Contact ◽  
Fs Laser ◽  
Micro Structures

With the recent expansion of additive manufacturing (AM) in industries, there is an intense need to improve the surface quality of AM parts. A functional surface with extreme wettability would explore the application of AM in medical implants and microfluid. In this research, we propose to superimpose the femtosecond (fs) laser induced period surface structures (LIPSS) in the nanoscale onto AM part surfaces with the micro structures that are fabricated in the AM process. A hierarchical structure that has a similar morphology to a lotus leaf surface is obtained by combining the advantages of liquid assisting fs laser processing and AM. A water contact angle (WCA) of 150° is suggested so that a super hydrophobic surface is achieved. The scanning electron microscopy (SEM) images and X-ray photoelectron spectroscopy (XPS) analysis indicate that both hierarchical structures and higher carbon content in the laser processed area are responsible for the super hydrophobicity.

scholarly journals Preparation of Graphite Oxide Containing Different Oxygen-Containing Functional Groups and the Study of Ammonia Gas Sensitivity

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3745 ◽  
Author(s):  
Liming Luo ◽  
Tongjiang Peng ◽  
Mingliang Yuan ◽  
Hongjuan Sun ◽  
Shichan Dai ◽  
...  
Keyword(s):  
Moisture Content ◽  
Functional Groups ◽  
Reaction Temperature ◽  
Graphite Oxide ◽  
Photoelectron Spectroscopy ◽  
Raw Material ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gas Sensitivity ◽  
X Ray

A series of graphite oxide samples were prepared using the modified Hummers method. Flake graphite was used as the raw material and the reaction temperature of the aqueous solution was changed (0 °C, 30 °C, 50 °C, 60 °C, 70 °C, 80 °C, and 100 °C). X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectral analysis, X-ray photoelectron spectroscopy, and contact angle tests were performed to characterize the structure, chemical bonding, type, and content of oxygen-containing functional groups of the graphite oxide samples. The results showed that the type and content of each oxygen-containing functional group could be controlled by changing the reaction temperature with the addition of water. As the temperature of the system increased, the degree of oxidation of the graphite oxide samples first increased and then decreased. Too high a temperature (100 °C) of the system led to the formation of epoxy groups by the decomposition of some hydroxyl groups in the samples, causing the reduction of oxygen-containing functional groups between the graphite layers, poor hydrophilic properties, and low moisture content. When the system temperature was 50 °C, the interlayer spacing of the graphite oxide samples was at its highest, the graphite was completely oxidized (C/O = 1.85), and the oxygen-containing functional groups were mainly composed of hydroxyl groups (accounting for approximately 28.88% of the total oxygen-containing functional groups). The high content of hydroxyl and carboxyl groups had good hydrophilic ability and showed the highest moisture content. The sample at 50 °C had better sensitivity to ammonia because of its high hydroxyl group and carboxyl group content, with the sample showing an excellent profile when the ammonia concentration was 20–60 ppm.

scholarly journals Mechanical Properties of Graphene Oxide Coupled by Multi-Physical Field: Grain Boundaries and Functional Groups

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Xu Xu ◽  
Zeping Zhang ◽  
Wenjuan Yao
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Grain Boundaries ◽  
Functional Groups ◽  
Oxygen Content ◽  
Tensile Fracture ◽  
Hydroxyl Groups ◽  
Molecular Configuration ◽  
Spatial Design ◽  
Out Of Plane

Graphene and graphene oxide (GO) usually have grain boundaries (GBs) in the process of synthesis and preparation. Here, we “attach” GBs into GO, a new molecular configuration i.e., polycrystalline graphene oxide (PGO) is proposed. This paper aims to provide an insight into the stability and mechanical properties of PGO by using the molecular dynamics method. For this purpose, the “bottom-up” multi-structure-spatial design performance of PGO and the physical mechanism associated with the spatial structure in mixed dimensions (combination of sp2 and sp3) were studied. Also, the effect of defect coupling (GBs and functional groups) on the mechanical properties was revealed. Our results demonstrate that the existence of the GBs reduces the mechanical properties of PGO and show an “induction” role during the tensile fracture process. The presence of functional groups converts in-plane sp2 carbon atoms into out-of-plane sp3 hybrid carbons, causing uneven stress distribution. Moreover, the mechanical characteristics of PGO are very sensitive to the oxygen content of functional groups, which decrease with the increase of oxygen content. The weakening degree of epoxy groups is slightly greater than that of hydroxyl groups. Finally, we find that the mechanical properties of PGO will fall to the lowest values due to the defect coupling amplification mechanism when the functional groups are distributed at GBs.

scholarly journals Dry Etching Performance and Gas-Phase Parameters of C6F12O + Ar Plasma in Comparison with CF4 + Ar

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1595
Author(s):  
Nomin Lim ◽  
Yeon Sik Choi ◽  
Alexander Efremov ◽  
Kwang-Ho Kwon
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Reactive Ion Etching ◽  
Research Work ◽  
Optical Emission ◽  
Plasma Parameters ◽  
Ion Etching ◽  
Ar Plasma ◽  
Ar Gas ◽  
Etching Selectivity

This research work deals with the comparative study of C6F12O + Ar and CF4 + Ar gas chemistries in respect to Si and SiO2 reactive-ion etching processes in a low power regime. Despite uncertain applicability of C6F12O as the fluorine-containing etchant gas, it is interesting because of the liquid (at room temperature) nature and weaker environmental impact (lower global warming potential). The combination of several experimental techniques (double Langmuir probe, optical emission spectroscopy, X-ray photoelectron spectroscopy) allowed one (a) to compare performances of given gas systems in respect to the reactive-ion etching of Si and SiO2; and (b) to associate the features of corresponding etching kinetics with those for gas-phase plasma parameters. It was found that both gas systems exhibit (a) similar changes in ion energy flux and F atom flux with variations on input RF power and gas pressure; (b) quite close polymerization abilities; and (c) identical behaviors of Si and SiO2 etching rates, as determined by the neutral-flux-limited regime of ion-assisted chemical reaction. Principal features of C6F12O + Ar plasma are only lower absolute etching rates (mainly due to the lower density and flux of F atoms) as well as some limitations in SiO2/Si etching selectivity.

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