scholarly journals Influence of Surface Modified Nanodiamonds on Dielectric and Mechanical Properties of Silicone Composites

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1104 ◽  
Author(s):  
Alexandra Shakun ◽  
Rafal Anyszka ◽  
Essi Sarlin ◽  
Anke Blume ◽  
Jyrki Vuorinen
Keyword(s):  
Energy Harvesting ◽  
Crosslinking Reaction ◽  
Mechanical Hysteresis ◽  
Viscous Losses ◽  
Carboxylic Groups ◽  
Dynamic Loss ◽  
Surface Modified ◽  
Chemical Groups ◽  
Dielectric And Mechanical Properties ◽  
Silicone Matrix

Detonation nanodiamonds, also known as ultradispersed diamonds, possess versatile chemically active surfaces, which can be adjusted to improve their interaction with elastomers. Such improvements can result in decreased dielectric and viscous losses of the composites without compromising other in-rubber properties, thus making the composites suitable for new demanding applications, such as energy harvesting. However, in most cases, surface modification of nanodiamonds requires the use of strong chemicals and high temperatures. The present study offers a less time-consuming functionalization method at 40 °C via reaction between the epoxy-rings of the modifier and carboxylic groups at the nanodiamond surface. This allows decorating the nanodiamond surface with chemical groups that are able to participate in the crosslinking reaction, thus creating strong interaction between filler and elastomer. Addition of 0.1 phr (parts per hundred rubber) of modified nanodiamonds into the silicone matrix results in about fivefold decreased electric losses at 1 Hz due to a reduced conductivity. Moreover, the mechanical hysteresis loss is reduced more than 50% and dynamic loss tangent at ambient temperature is lowered. Therefore, such materials are recommended for the dielectric energy harvesting application, and they are expected to increase its efficiency.

Dielectric and Mechanical Properties of Surface Modified Organosilicate Films

2005 ◽  
Vol 35 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Suzhu Yu ◽  
Terence K. S. Wong ◽  
Xiao Hu ◽  
Ming Shyan Yong
Keyword(s):  
Mechanical Properties ◽  
Surface Modified ◽  
Dielectric And Mechanical Properties

scholarly journals SURFACE MODIFICATION OF CANARIUM OVATUMENGL.(PILI) SHELL AS ADSORBENT OF LEAD(Pb2+) FROM AQUEOUS SOLUTION

2021 ◽  
Author(s):  
Ernesto Jr. S. Cajucom ◽  
◽  
Lolibeth V. Figueroa ◽  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Cost Effective ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Carboxylic Groups ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Surface Modified

This study was carried out to investigate the efficiency of raw pili shell (RPS) and the surface modified pili shell using EDTA (EMPS) and oxalic acid (OMPS). A comparative study on the adsorption capacity of the adsorbents was performed against lead (Pb2+) from aqueous solution. The adsorbents were characterized by FTIR, which showed higher peak of adsorption bands of carboxylic groups on the acid modified pili shells. Scanning electron microscope orSEM was also used to describe the surface morphology of the adsorbents. The linear form of Langmuir and Freundlich models were applied to represent adsorption data. The calculated equilibrium data of Pb (II) best fitted to Langmuir compare to Freundlich isotherm model with maximum adsorption capacity (qmax) of 27.03 mg/g and 45.45 mg/g using EMPS and OMPS, respectively. Kinetic sorption models were used to determine the adsorption mechanism and the kinetic data of all the adsorbents correlated (R2=1) wellwith the pseudo second order kinetic model. Among the three adsorbents, OMPS shown higher percent removal of lead compared to RPS and EMPS. The large adsorption capacity rate indicated that chemically modified pili shell in present study has great potential to be used as a cost-effective adsorbent for the removal of lead ions from the water.

A Triboelectric Nanogenerator (TENG) for Pipeline Monitoring

2018 ◽  
Author(s):  
M. Taylan Das ◽  
Kavinaath Murugan ◽  
Adam Tetreault ◽  
Connor Irvine ◽  
Andrej Rosic ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Output Power ◽  
Vibrational Energy ◽  
Triboelectric Nanogenerator ◽  
Alternative Materials ◽  
Oil Pipelines ◽  
Triboelectric Nanogenerators ◽  
Surface Modified ◽  
Vibrational Energy Harvesting ◽  
Triboelectric Energy Harvesting

In this study, we present triboelectric nanogenerators (TENGs) for vibrational energy harvesting in oil pipelines. The generators are designed to replenish the batteries of leak detection sensor, thereby increasing their lifespan and reducing the need for maintenance. The TENGs were designed to harvest energy from a 12-inch diameter pipeline, vibrating with at 32 Hz. Three alternative materials were used for the upper plate of a 4 × 4 cm TENG, namely Polytetrafluoroethylene (PTFE), unstructured polydimethylsiloxane (PDMS) and structured PDMS. Tests revealed that the unstructured PDMS TENG outperformed the PTFE TENG and generated 47.6 μW of power. Structuring the PDMS by patterning open channels on half of the surface increased the output power to 200.0 μW. When the spring constant of the structured PDMS TENG was optimized, the output power was further increased to 297.7 μW. These results demonstrate that structured PDMS shows promise in triboelectric energy harvesting, specifically because it can be surface-modified using inexpensive techniques that do not require a clean room.

scholarly journals Improved Dielectric Properties of Thermoplastic Polyurethane Elastomer Filled with Core–Shell Structured PDA@TiC Particles

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3341
Author(s):  
Xinfu He ◽  
Jun Zhou ◽  
Liuyan Jin ◽  
Xueying Long ◽  
Hongju Wu ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Thermoplastic Polyurethane ◽  
Low Loss ◽  
Elongation At Break ◽  
The Matrix ◽  
Potential Applications ◽  
Low Levels ◽  
Surface Modified ◽  
Dielectric And Mechanical Properties

Insulating interlayer between nanoparticles and polymer matrix is crucial for suppressing the dielectric loss of polymer composites. In this study, titanium carbide (TiC) particles were surface modified by polydopamine (PDA), and the obtained PDA@TiC powders were used to reinforce thermoplastic polyurethane (TPU). The results indicate that the PDA@TiC were homogenously dispersed in the matrix compared with the pristine TiC, and that the PDA@TiC/TPU composites show improved dielectric and mechanical properties, i.e., much lower dissipation factors and obviously enhanced dielectric breakdown strength, as well as higher tensile strength and elongation at break as compared to the raw TiC/TPU. The nanoscale PDA interlayer contributes to the dielectric and mechanical enhancements because it not only serves as an insulating shell that prevents TiC particles from direct contacting and suppresses the loss and leakage current to very low levels, but also enhances the interfacial interactions thereby leading to improved mechanical strength and toughness. The prepared flexible PDA@TiC/TPU with high permittivity but low loss will find potential applications in electronic and electrical applications.

Synthesis and Characterization of CMC for Potential Application as Adsorbent in Water Treatment

2016 ◽  
Vol 869 ◽  
pp. 750-755 ◽  
Author(s):  
Fernanda Guerra Lima Medeiros Borsagli ◽  
Alexandra A.P. Mansur ◽  
Herman Sander Mansur
Keyword(s):  
Water Treatment ◽  
Good Alternative ◽  
Carboxymethyl Chitosan ◽  
Synthesis And Characterization ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
Carboxylic Groups ◽  
Ph Range ◽  
Chemical Groups

Chitosan is a polymer from natural source with a wide range of applications, such as in the adsorption of heavy metals. However, it presents limitation in relation to pH, because it is insoluble in neutral and alkaline. Thus, a good alternative has been the use of derivatives of chitosan, as carboxymethyl chitosan (CMC). This chemical modification of chitosan may favor the adsorption process, because it broadens the pH range of solubility and the quantity of chemical groups available for the uptake of ions. This work was carried out the synthesis and characterization of carboxymethyl chitosan. The properties of derivatives synthesized were assessed through the study of solubility at different pHs and using the techniques of potentiometric titration, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis) spectroscopy and thermal analysis. The results have demonstrated the effective incorporation of carboxylic groups in the structure of chitosan, as well as the dependence of degree of substitution with the concentration of hydroxide during the synthesis. Hence, the chemical functionalization of chitosan for producing carboxymethyl chitosan offers the possibility of applying this new adsorbent for water treatment.

scholarly journals Covalent Surface Functionalization of Bovine Serum Albumin to Magnesium Surface: Enhancing Robust Corrosion Inhibition and In vitro Osteo-Inductivity

2019 ◽  
Author(s):  
Seo Yeon Lee ◽  
Sita Shrestha ◽  
Bishnu K Shrestha ◽  
Chan Hee Park ◽  
Cheol Sang Kim
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Cost Effective ◽  
Corrosion Current ◽  
Covalent Modification ◽  
Carboxylic Groups ◽  
Bonding Method ◽  
Surface Modified

Herein, we describe precisely on covalent modification of pure magnesium (Mg) surface and applied to induce in vitro osteogenic differentiation. A new concept, chemical bonding method is proposed for developing stable chemical bonds on Mg surface through serial assembly of bioactive additives including ascorbic acid (AA) and bovine serum albumin (BSA). The coating with such potential materials shows strong integrity to the Mg and could suitable for cell-interface interaction with the host tissue during implantation in bone tissue repair. The physicochemical and electrochemical properties of surface modified Mg assess how these nanoscales layered of biomolecules could demonstrate the significance improvement in chemical stability of coating. The modified Mg-OH-AA-BSA exhibits better anti-corrosion behavior with high corrosion potential (Ecorr ~ ‒ 0.96 V) and low corrosion current density (Icorr ~ 0.2 µA cm-2) as compared to pure Mg (Ecorr ~ ‒1.46 V, Icorr ~ 10.42 µA cm-2). Outer layer of BSA on Mg protects fast degradation rate of Mg which is the consequence of strong chemicals bonds between amine groups on BSA with carboxylic groups on AA. Collectively, the results suggest that surface modified Mg provides strong bio-interface and enhances the proliferation and differentiation of pre-osteoblast (MC3T3-E1) cells through protein-lipid interaction. Owing to this fact, the cost-effective and scalable covalent functionalization of Mg surface inherits biological advantage in orthopedic and dental implants with long term stability.

Small Angle X-Ray Scattering, FTIR and SEM Characterization of Nanostructured PVA/TEOS Hybrids by Chemical Crosslinking

2005 ◽  
Vol 873 ◽  
Author(s):  
Herman S. Mansur ◽  
Alexandra A.P. Mansur
Keyword(s):  
Small Angle ◽  
Hybrid Network ◽  
Poly Vinyl Alcohol ◽  
Crosslinking Reaction ◽  
Absorption Bands ◽  
X Ray ◽  
X Ray Scattering ◽  
Potential Applications ◽  
Chemical Groups ◽  
Ray Scattering

AbstractIn the present work, novel hybrid nanostructured composites were produced to be used in many potential applications such as biomedical, drug delivery systems, tri-dimensional scaffolds for biomaterials and tissue engineering, biomembranes and optical devices among others. Hybrids were synthesized by reacting poly (vinyl alcohol) (PVA) in aqueous acid solution with silicon alcoxide tetraethoxysilane (TEOS). PVA/TEOS hybrids were also modified in the nanometer-scale by crosslinking with glutaraldehyde (GA) during the synthesis involving hydrolysis and policondensation of PVA/TEOS. The hybrids were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Small Angle X-ray Scattering (SAXS) and Scanning Electron Microscopy (SEM). FTIR spectra have shown major vibration bands associated with organic-inorganic chemical groups present in the hybrid composite PVA/TEOS. Also, typical absorption bands related to glutaraldehyde alkyl chain have indicated the crosslinking reaction of the hybrid network with glutaraldehyde (PVA/TEOS/GA). SAXS results have indicated different nano-ordered disperse phases for PVA, PVA/TEOS hybrid and PVA/TEOS/GA chemically crosslinked hybrid. SEM micrographs have shown morphology difference between PVA and PVA hybrid samples.

Analytical Electron Microscopy of Surface-Modified Ceramics

1985 ◽  
Vol 43 ◽  
pp. 276-279
Author(s):  
P. S. Sklad
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Theoretical Models ◽  
Ceramic Materials ◽  
Solute Concentration ◽  
Second Phase ◽  
Analytical Electron ◽  
Implantation Techniques ◽  
Lattice Damage ◽  
Surface Modified

Over the past several years, it has become increasingly evident that materials for proposed advanced energy systems will be required to operate at high temperatures and in aggressive environments. These constraints make structural ceramics attractive materials for these systems. However it is well known that the condition of the specimen surface of ceramic materials is often critical in controlling properties such as fracture toughness, oxidation resistance, and wear resistance. Ion implantation techniques offer the potential of overcoming some of the surface related limitations.While the effects of implantation on surface sensitive properties may be measured indpendently, it is important to understand the microstructural evolution leading to these changes. Analytical electron microscopy provides a useful tool for characterizing the microstructures produced in terms of solute concentration profiles, second phase formation, lattice damage, crystallinity of the implanted layer, and annealing behavior. Such analyses allow correlations to be made with theoretical models, property measurements, and results of complimentary techniques.

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