Effect of Ionic Liquid on the Properties of Nanocomposites Based on Epoxy/CNT Hardened with MCDEA

Thermosetting systems based on epoxy resin (RE) with the dispersion of carbon nanotubes (CNT), have been extensively studied by the development of high-performance materials with interesting mechanical, thermal and electrical properties that the thermo-rigid system achieves with the addition of CNT, and thus contribute to obtain composites with excellent performance in low amounts of this filler. However, ensuring a good dispersion of these systems is not easy, as CNTs have a great tendency to cluster due to Van der Waals interactions. To assist in the dispersion of the systems, a phosphonium-based ionic liquid, tributyl (ethyl) -phosphonium diethyl phosphate, acted with a double role, as a dispersion agent and catalyst in systems hardened with MCDEA (4,4’-methylenebis (3 - chloro-2,6-diethylaniline), which is a solid compound giving the systems high viscosity, and with the addition of LI improved the dispersion of the systems, as well as the processability in the preparation of the nanocomposites.

Extension of the Scope of Anionic Phospholipid-Based Nanoformulation to Kaempferol and Indometacin

In this work, resveratrol was dispersed with anionic phospholipids of 1,2-dipalmitoyl-sn-glycero-3-phosphorylglycerol (DPPG), 1,2-dipalmitoyl-sn-glycero-3-phosphatidic acid, and 1,2-distearoyl-sn-glycero-3-phosphoglycerol. Moreover, small-sized nanoparticles of kaempferol and indometacin were successfully prepared by using DPPG as a dispersion agent.

Effective Casting Technique of Nano-Particles Alloyed Austenitic Stainless Steel

In recent decades, considerable efforts have been made in the production of steel and the modification of its microstructure on the nano-scale in order to improve its mechanical properties. One possibility is through nano-particles incorporation and reinforcement. While typical production methods for Metal Matrix nano-Composites (MMnCs) are difficult and expensive, the main drawback of the casting method is the agglomeration of the nano-particles and a poor interface between the nano-particles and the metal matrix. Therefore, the aim of this study was to investigate the potential of adding nano-particles as reinforcement elements through the conventional liquid-metal casting process. The investigation was focused on the various approaches to the modification and addition of nano-particles in the melt, as well as the influence of particle concentration and size on their homogeneity and distribution within the steel matrix. The results show that also in the case of the conventional casting process, it is possible to produce a reinforced steel-matrix nano-composite with a homogeneous distribution of the Al2O3 nano-particles in the matrix. However, in order to obtain a homogeneous distribution of nano-particles in the steel matrix, a dispersion agent is required.

A study on the functional and tensile properties of polyurethane composite film with carbon nanotube fibers

The purpose of this study is to propose a process of fabricating conductive polyurethane (PU)/CNT composite films that possess electrostatic discharge (ESD), UV cut, and warming characteristics. Polyvinylpyrrolidone (PVP), Methyl Ethyl Ketone (MEK), Isopropanol (IPA) were used as the dispersion agent to facilitate the dispersion of CNT fiber before blending with PU in a planetary stirring defoaming machine for thorough uniform mixing. In this study, various amounts of CNT fibers were added into the solvent-based PU solution to improve the electrical conductivity of the conventional PU product. Based on the test results, the PU with CNT fiber shows better performance than that of conventional PU. This paper successfully prepared the PU/CNT composite film which coat on the fabric to prevent static electricity generation, rapid warming, improve home security and the versatility of outdoor and camouflage military products applications.

PENGARUH RUTE SINTESIS TERHADAP KEEFEKTIFAN PENGIKATAN GUGUS PDETA PADA SINTESIS Fe3O4@SiO2@PDETA

Synthesis of Fe3O4@SiO2 modified with propyldiethylenetriamine (Fe3O4@SiO2@PDETA) with variation of synthesis routes have been investigated. Research was begun with synthesis of Fe3O4 using dispersion agent of trisodium citrate at coprecipitation system through stirring using ultrasonic wave. Coating magnetite with propyldiethylenetriamine modified silica was carried out through sol-gel process with two different mixing sequences of raw materials (two synthesis routes) with main materials of Fe3O4 synthesized, N-[3-(Trimethoxysilyl)propyl]-diethylenetriamine (TMSPDETA) and Na2SiO3. The products were characterized by fourier transform infrared (FTIR) spectrophotometer and scanning electron microscope-energy dispersive X-ray (SEM-EDX). Results indicate that Fe3O4@SiO2@PDETA has been synthesized succesfully. Fe3O4@SiO2@PDETA synthesized through route 1 (magnetite mixed with a mixture TMSPDETA and Na2SiO3) contains more propyldiethylenetriamine group than that of through route 2 (magnetite mixed with Na2SiO3 solution, then mixed with TMSPDETA)

Further Enhancement of Mechanical Properties of Conducting Rubber Composites Based on Multiwalled Carbon Nanotubes and Nitrile Rubber by Solvent Treatment

Post-treatment removal of dispersion agents from carbon nanotube/rubber composites can greatly enhance the mechanical properties by increasing the filler–matrix interaction. In this study, multiwall carbon nanotubes (MWNT) were dispersed in water by sonication and nonionic surfactant, octyl-phenol-ethoxylate was used as a dispersion agent. The dispersed MWNTs were incorporated in thermo-reactive acrylonitrile butadiene rubber (NBR) latex and nanocomposite films were prepared by solution casting. As a post-treatment, the surfactant was removed with acetone and films were dried in air. Dispersion quality of the colloid before casting was determined, and mechanical, electrical and thermal properties of the composites before and after the acetone post-treatment were studied. It was found that removal of dispersion agent increased the storage modulus of films between 160–300% in all samples. Relative enhancement was greater in samples with better dispersion quality, whereas thermal conductivity changed more in samples with smaller dispersion quality values. Electrical properties were not notably affected.

Micromechanism of the Dispersion Behavior of Polymer-Modified Rejuvenators in Aged Asphalt Material

Polymer-modified rejuvenator has a different composition and dispersion behavior to traditional rejuvenators. The objective of this study was to investigate the micromechanism of polymer-modified rejuvenators on the behavior of aged asphalt binder. Firstly, gel permeation chromatography (GPC) analysis was conducted to determine the dispersion effectiveness. Secondly, the dispersal behavior of polymer-modified rejuvenators was studied by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM). Rheological, toughness-tenacity, and force–ductility analyses of the rejuvenated asphalt binder were additionally performed. The results indicate that the contacted asphaltenic micelles in aged asphalt binder were dispersed by dispersion agent in the polymer-modified rejuvenator, and that the dispersion ability of the polymer-modified rejuvenator was promoted to the commercial rejuvenator level. Additionally, the polymer-modified rejuvenator was found to improve the rejuvenated asphalt binder’s resistance to deformation, through the formation of polymeric network structures in the asphalt binder. The results may be used to improve the performance of rejuvenated asphalt binder in recycled-pavement engineering.