scholarly journals Plasma Mediated Chlorhexidine Immobilization onto Polylactic Acid Surface via Carbodiimide Chemistry: Antibacterial and Cytocompatibility Assessment

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1201
Author(s):  
Kadir Ozaltin ◽  
Antonio Di Martino ◽  
Zdenka Capakova ◽  
Marian Lehocky ◽  
Petr Humpolicek ◽  
...  

The development of antibacterial materials has great importance in avoiding bacterial contamination and the risk of infection for implantable biomaterials. An antibacterial thin film coating on the surface via chemical bonding is a promising technique to keep native bulk material properties unchanged. However, most of the polymeric materials are chemically inert and highly hydrophobic, which makes chemical agent coating challenging Herein, immobilization of chlorhexidine, a broad-spectrum bactericidal cationic compound, onto the polylactic acid surface was performed in a multistep physicochemical method. Direct current plasma was used for surface functionalization, followed by carbodiimide chemistry to link the coupling reagents of N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDAC) and N-Hydroxysuccinimide (NHs) to create a free bonding site to anchor the chlorhexidine. Surface characterizations were performed by water contact angle test, X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). The antibacterial activity was tested using Staphylococcus aureus and Escherichia coli. Finally, in vitro cytocompatibility of the samples was studied using primary mouse embryonic fibroblast cells. It was found that all samples were cytocompatible and the best antibacterial performance observed was the Chlorhexidine immobilized sample after NHs activation.

2021 ◽  
Vol 270 ◽  
pp. 01011
Author(s):  
Tereza Smejkalová ◽  
Ştefan Ţălu ◽  
Rashid Dallaev ◽  
Klára Částková ◽  
Dinara Sobola ◽  
...  

Polyvinylidene fluoride (PVDF) is one of the most promising electroactive polymers; it exhibits excellent electroactive behaviours, good biocompatibility, excellent chemical resistance, and thermal stability, rendering it an attractive material for biomedical, electronic, environmental and energy harvesting applications. This work aims to further improve its properties by the inclusion of powders of piezoactive materials. Polyvinylidene fluoride was formed by electrospinning into fibres with a thickness of 1.5-0.3 µm and then examined in a scanning electron microscope. The work offers a description of the current procedure in the preparation of samples and their modification for examination in a scanning electron microscope, characterizes the individual components of doped fibres and deals with specific instruments used for various analytical methods. The work contains a theoretical introduction to the analytical methods to which the samples will be further subjected, such as energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS). The obtained excellent properties of doped PVDF could be used in the design of sensors.


Author(s):  
A.G. Fitzgerald ◽  
S.M. Potrous

The diffusion of silver in amorphous chalcogenides is the basis for high-resolution lithographic applications. Previous studies of the diffusion of silver on contact with chalcogenide films has been studied by Auger depth profiling and the effects of photodoping on chemical bonding have been studied by x-ray photoelectron spectroscopy. Electron lithographic effects have been studied in the transmission electron microscope.The objective of the investigation described here has been to determine the degree of diffusion of silver in the amorphous chalcogenides, As2S3, As2Se3, GeS and GeSe when these films are in contact with thin silver films. The silver distribution has been determined by x-ray microanalysis of film cross-sections in the scanning electron microscope (SEM). Electron beam induced conductivity (EBIC) at points in these films has also been investigated.


2020 ◽  
Vol 27 (11) ◽  
pp. 2050003
Author(s):  
HONGXIA LI ◽  
CHAO YANG ◽  
JIAN ZHANG ◽  
XIANGUO LIU ◽  
XUEFENG ZHANG

Recently, Co(OH)2 has gained much attention as a promising electrocatalyst. Herein, we synthesized Co(OH)2-decorated TiO2 film for electrocatalytic water splitting by a facile and low-cost electrochemistry method, which possessed enhanced performance for oxygen evolution reaction. The results of X-ray diffractometry, transmission electron microscope, scanning electron microscope and X-ray photoelectron spectroscopy verify the successful decoration of Co(OH)2 electrocatalysts onto the surface of TiO2. Moreover, photoelectrocatalytic measurements illustrate that the Co(OH)2-decorated TiO2 shows higher current density than pure TiO2 sample. The results obtained in this work give deep insights into the development of photoelectrochemical water splitting.


2012 ◽  
Vol 512-515 ◽  
pp. 894-897
Author(s):  
Si Hui Wang ◽  
He Yun Wang ◽  
Fan Xing Meng ◽  
Ya Li Li

Abstract: The introduction of metal atoms into SiBCN network allows the development of novel high temperature ceramics and functional ceramics. In this work, cerium (Ce) containing polyborosilazane (PBSZ) is synthesized through substitution and polymerization reactions. Ce atoms are incorporated into PBSZ through the lithium replacement of H in PBSZ followed by Ce replacement of lithium. The chemical structure of the PBSZ and as-synthesized Li containing PBSZ are analyzed by Fourier transform infrared (FTIR) shows that the bands at 598 and 1183 cm-1 which can be assigned to Li-N and Si-N-Li stretching. It is suggested that lithium is incorporated into PBSZ. PBSZCe is transformed into SiBCNCe ceramic by pyrolysed in argon. Scanning electron microscope shows that the SiBCNCe ceramics are porous on the surface and corallike in the section. The chemical bondings of SiBCNCe ceramics are BN, the BN, SiC and Si3N4 characterized by X-ray photoelectron spectroscopy.


2020 ◽  
pp. 2050047
Author(s):  
YU LIANG ◽  
WEIHUA AO ◽  
HAO DING ◽  
KAI SHEN

Talc/TiO2 composite particle was prepared with TiO2 coating on the surfaces of the talc particles by mechano-chemical method. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to investigate the microstructures and morphologies of the composite particles. The mechanism of the mechano-chemical reaction was researched by infrared spectra (IR) and X-ray photoelectron spectroscopy (XPS). The prepared talc/TiO2 composite particle has similar pigment properties compared with TiO2, with its hiding power 10.45[Formula: see text]g/cm3 and whiteness 97.49%. The results show that TiO2 coated evenly on the surfaces of the talc particles by Si–O–Ti and Mg–O–Ti bonds through surface dehydroxylation reaction.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 294 ◽  
Author(s):  
Junlei Tang ◽  
Xi Yang ◽  
Yingying Wang ◽  
Hu Wang ◽  
Ying Xiao ◽  
...  

The corrosion behavior of 2205 DSS in HCl solutions containing sulfide were investigated using mass loss test, electrochemical measurements, scanning Kelvin probe, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that Na2S had significant effect on corrosion behavior of 2205 DSS in dilute HCl solutions. Slight Na2S can prevent the passive film from localized attacking of Cl- in HCl solution with a concentration lower than 0.1 mol/L. However, when the concentration of HCl solution higher than 0.137 mol/L, Na2S addition will tremendously promote corrosion. The intergranular corrosion combined surficial active dissolution of 2205 DSS could happen in HCl + Na2S solution.


2021 ◽  
Author(s):  
TianXia LIU ◽  
jian Qin ◽  
Jian Wang ◽  
jing Li

Abstract Purpose To study the effect of oleic acid surface modified RGO/MoS2 composite lubricating additives on the friction and wear properties of 10# White Oil (10# WO). Method The influence of different concentrations of reduction graphene oxide/molybdenum disulfide (RGO-MoS2) and oleic acid surface modified reduction graphene oxide/molybdenum disulfide (OA-RGO-MoS2) on the lubricating properties in 10# WO was investigated by using a four-ball long-term friction and wear tester. The microscopic morphology, lattice structure, composition and element valence of the prepared material were characterized by scanning electron microscope, Raman spectroscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, element analyzer and other instruments. The diameter, structure, morphology, composition and element valence state of the wear scar were obtained by multifunctional universal tool microscope, scanning electron microscope and X-ray photoelectron spectroscopy. Result In the RGO-MoS2 white oil system, when 0.4 wt% RGO-MoS2 was added, the anti-friction effect was the best, and the average friction coefficient (AFC) reduced by 21.8%. When 0.2 wt% RGO-MoS2 was added, the anti-wear effect was the optimal, and the average wear scar diameter (AWSD) decreased by 12.4%. In the OA-RGO-MoS2 white oil system, when 0.2 wt% OA-RGO-MoS2 was added, the anti-friction and anti-wear effects were the best, and the AFC reduced by 33.3%, and AWSD reduced by 14.1%. Conclusion Compared with RGO-MoS2, OA-RGO-MoS2 has a higher degree of graphitization, larger interlayer spacing, lower degree of layered accumulation, higher MoS2 load, and weaker thermal stability. Both lubricating additives have good anti-friction and anti-wear effects at low concentrations, and the anti-friction and anti-wear effects are more prominent after being modified by oleic acid. Analysis of friction mechanism shows that a lubricating protective film containing iron, oxygen, molybdenum, carbon, and sulfur is formed through adsorption or tribochemical reaction during the friction process, which improves the lubrication state and plays a role in reducing friction and anti-wear.


2011 ◽  
Vol 306-307 ◽  
pp. 1375-1378 ◽  
Author(s):  
Ling Zhang ◽  
Ling Li ◽  
Zong Gang Mou ◽  
Xi Feng Li

BCN–TiO2 was prepared by doping Ti(OH)4 with graphite-like structure BCN in an annealing process at 400[°C] for 2[h]. The catalyst samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). Graphite-like structure BCN was detected by XRD. The results showed that with graphite-like structure BCN doped in, the crystal size became smaller than pure TiO2. Also B, C, N were detected in crystal lattice of TiO2, in which Boron was in the form of Bx+, Carbon substituted some of the lattice oxygen atoms as Ti-C, and Nitrogen was in the form of Ti-N and Ti-O-N.


2011 ◽  
Vol 356-360 ◽  
pp. 106-109 ◽  
Author(s):  
Yan Ling Bao ◽  
Guang Ze Dai ◽  
Chuan Jiang

PAN-based carbon fiber (CF) was modified by hypochlorous and urea in current treatments. The CF surface morphology and natures were characterized by specific facilities, such as scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and the degree of moisture. On the other hand, the biocompatibility nature was indicated by immobilization results of microorganisms on CF. The results show that the surface hydrophilicity and roughness of CF surface would contribute greatly to improve the immobilization ability of microorganisms on CF surface, and the produced oxygen on CF has more effect on microorganism immobilization than nitrogen.


Author(s):  
W. Brünger

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.


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