scholarly journals Functionalization of Natural Cork Composite with Microcapsules after Plasma Treatment

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Fernando Ribeiro Oliveira ◽  
Etienne Albino A. Silva ◽  
Sidney Nascimento do Carmo ◽  
Fernanda Steffens ◽  
António Pedro Garcia de Valadares Souto

This research aims to study the chemical and physical modifications of natural cork agglomerate after plasma treatment using dielectric barrier discharge (DBD). Different experimental techniques were used to evaluate the surface alterations of the pretreated samples with DBD plasma, as well as the adsorption and adhesion of microcapsules in the substrate, namely, static and dynamic contact angle, surface energy, energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Plasma discharge greatly increases the wettability and surface energy of the samples. Chemical and physical analyses of the cork agglomerate confirmed considerable surface modification. All these surface changes of the cork after plasma treatment led to a remarkable increase in microcapsule adsorption and adhesion when compared with the untreated cork sample.

2020 ◽  
pp. 095400832095706
Author(s):  
Jennifer Vinodhini ◽  
K Sudheendra ◽  
Meera Balachandran ◽  
Shantanu Bhowmik

This investigation highlights argon plasma treatment on Poly-aryl-ether-ketone (PAEK) and carbon fibre (CF) surface. The PAEK and CF surface is modified for 300 sec and the change in physiochemical and mechanical properties were investigated through Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Contact angle, Atomic Force Microscope (AFM) and Tensile Test. FTIR of surface modified PAEK revealed the stretching of C-H, C=C and C=O functional groups. A reversal phenomenon of increased surface energy was observed through dynamic contact angle study of CF and to further examine the surface energy effect, AFM analysis on CF was carried out revealing increased roughness with numerous micro dents formation. PAEK/CF composite samples were fabricated through compression moulding technique. The change in mechanical properties due to surface modification were analysed through Tensile testing on surface modified PAEK/CF sample and untreated PAEK/CF samples. The surface treated PAEK/CF showed increased tensile strength than untreated PAEK/CF. The argon plasma treatment helped in creating depth striations that lead to better interlocking of resin matrix with the reinforced CF. The fracture surface was examined through Filed Emission Scanning Electron Microscope (FE-SEM) wherein the Micrographs of the tensile tested samples indicated failure of composite due to fibre breakage.


Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Mihai Asandulesa ◽  
Ionut Topala ◽  
Nicoleta Dumitrascu

Abstract The effects of helium dielectric barrier discharge (He-DBD) plasma treatment has been studied aiming at the preparation of wood for profitable dye covering and impregnation with an antibacterial oil. Electrical and optical emission spectroscopy measurements were performed to characterise the He-DBD discharge. The hydrophilic/hydrophobic properties of the modified surfaces were studied by dynamic contact angle measurements. The spreading area of the wet spots was also evaluated as a function of wetting time. After He-DBD plasma exposure, the adhesion properties are substantially improved and the hydrophilic character of wood surface is enhanced. The behaviour of linseed oil drops on the modified surfaces confirmed the utility of He-DBD treatment.


Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1731
Author(s):  
Man-Seok Choi ◽  
Eun Bi Jeon ◽  
Ji Yoon Kim ◽  
Eun Ha Choi ◽  
Jun Sup Lim ◽  
...  

This study investigates the effects of dielectric barrier discharge (DBD) plasma treatment (1.1 kV, 43 kHz, N2 1.5 L/min, 10~60 min) on human norovirus (HuNoV) GII.4 infectivity in fresh oysters. HuNoV viability in oysters was assessed by using propidium monoazide (PMA) as a nucleic acid intercalating dye before performing a real-time reverse transcription–quantitative polymerase chain reaction (RT-qPCR). Additionally, the impact of the DBD plasma treatment on pH and Hunter colors was assessed. When DBD plasma was treated for 60 min, the HuNoV genomic titer reduction without PMA pretreatment was negligible (<1 log copy number/µL), whereas when PMA treatment was used, HuNoV titer was reduced to >1 log copy number/µL in just 30 min. D1 and D2-value of HuNoV infectivity were calculated as 36.5 and 73.0 min of the DBD plasma treatment, respectively, using the first-order kinetics model (R2 = 0.98). The pH and Hunter colors were not significantly different (p > 0.05) between the untreated and DBD-plasma-treated oysters. The results suggest that PMA/RT-qPCR could help distinguish HuNoV infectivity without negatively affecting oyster quality following >30 min treatment with DBD plasma. Moreover, the inactivation kinetics of nonthermal DBD plasma against HuNoV in fresh oysters might provide basic information for oyster processing and distribution.


2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Bekim Osmani ◽  
Gabriela Gerganova ◽  
Bert Müller

AbstractPolydimethylsiloxanes (PDMS) have drawn attention because of their applicability in medical implants, soft robotics and microfluidic devices. This article examines the formation of dedicated nanostructures on liquid submicrometer PDMS films when exposed to oxygen-plasma treatment. We show that by using a vinyl-terminated PDMS prepolymer with a molecular weight of 800 g/mol, one can bypass the need of solvent, copolymer, or catalyst to fabricate wrinkled films. The amplitude and periodicity of the wrinkles is tuned varying the thickness of the PDMS film between 150 and 600 nm. The duration of the plasma treatment and the oxygen pressure determine the surface morphology. The amplitude was found between 30 and 300 nm with periodicities ranging from 500 to 2800 nm. Atomic force microscopy was used to measure film thickness, amplitude and wrinkle periodicity. The hydrophobic recovery of the nanostructured PDMS surface, as assessed by dynamic contact angle measurements, scales with nanostructure’s fineness, associated with an improved biocompatibility. The mechanical properties were extracted out of 10,000 nanoindentations on 50×50-μm


2021 ◽  
Vol 36 (3) ◽  
pp. 503-511
Author(s):  
Yazhou Xu ◽  
Songlin Dai ◽  
Liangwu Bi ◽  
Yuxiang Chen

Abstract A series of tung oil-rosin-based polyester (TRP) used as internal sizing agents were prepared using rosin, tung oil, maleic anhydride, and glycerol. TRP structure and properties were examined using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The TRP latexes were subsequently used as internal sizing agents, and the sizing properties were evaluated using a scanning electron microscope (SEM), a video-based dynamic contact angle measuring device and a Cobb absorbency tester. The optimal conditions for preparing the TRP sizing agent were as follows: the hydroxy-carboxyl ratio of the material was 0.25; the maleic anhydride dosage was 20 % of rosin; and the tung oil dosage was 40 % of rosin. Under the best conditions, the sized paper Cobb-60 was 15.6  g / m 2 \text{g}/{\text{m}^{2}} , the tensile index was 45.1 N·m/g, the burst index was 3.1 kPa· m 2 {\text{m}^{2}} /g, and the tear index was 15.6 mN· m 2 {\text{m}^{2}} /g.


RSC Advances ◽  
2018 ◽  
Vol 8 (28) ◽  
pp. 15372-15379 ◽  
Author(s):  
Min Hu ◽  
Binran Zhao ◽  
Dong-Yang Zhao ◽  
Mei-Ting Yuan ◽  
Huiyong Chen ◽  
...  

Template removal from MCM-22 using dielectric-barrier discharge (DBD) plasma could decrease the formation of extra-framework aluminum (EFAl) and increase the concentration of the acidic sites and external surface area of MCM-22.


2011 ◽  
Vol 284-286 ◽  
pp. 277-283 ◽  
Author(s):  
Ning Qi ◽  
Lei Zhao

Surfaces of jute fiber needled mats were treated by alkali, potassium permanganate and A-151 silane coupling respectively, and those reinforced vinyl resin composites were made by VARTM method . The changes of the surface energy of the jute fiber mats were analyzed basing on the dynamic contact angle, and the surface of the jute fiber and the interface morphology of the composites were observed by SEM. The results showed that interface compatibility and the comprehensive properties of the composites were improved evidently, because the surface energy of the jute fiber was lowered and the surface micro-structures of the fiber were changed. Especially, the tensile strength and flexural strength of the composites treated by A-151 silane coupling increased by 63.08% and 94.79% respectively.


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