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Journal articles on the topic "Grafted silica nanoparticle":
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Henoumont, Céline, Gauthier Hallot, Estelle Lipani, Catherine Gomez, Robert N. Muller, Luce Vander Elst, Marc Port, and Sophie Laurent. "Characterization of Organic Molecules Grafted to Silica or Bismuth Nanoparticles by NMR." Applied Nano 2, no. 4 (November 4, 2021): 330–43. http://dx.doi.org/10.3390/applnano2040024.
NMR is a powerful characterization tool and we propose to study the surface of silica or bismuth nanoparticles dedicated to medical applications in order to evidence the covalent grafting of organic molecules on their surface. For that aim, DOSY experiments are particularly useful and allow for the discrimination of molecules interacting strongly with the nanoparticle surface from molecules simply weakly adsorbed at the surface. We were able to characterize thoroughly the surface of different silica and bismuth nanoparticles.
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Holt, Adam P., and C. M. Roland. "Segmental and secondary dynamics of nanoparticle-grafted oligomers." Soft Matter 14, no. 42 (2018): 8604–11. http://dx.doi.org/10.1039/c8sm01443d.
Rose, Katie A., Daeyeon Lee, and Russell J. Composto. "pH-Mediated nanoparticle dynamics in hydrogel nanocomposites." Soft Matter 17, no. 10 (2021): 2765–74. http://dx.doi.org/10.1039/d0sm02213f.
The effect of static silica particles on the dynamics of quantum dot (QD) nanoparticles grafted with a poly(ethylene glycol) (PEG) brush in hydrogel nanocomposites is investigated using single particle tracking (SPT).
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Zhou, Tong Hui, Wen Hong Ruan, Min Zhi Rong, and Ming Qiu Zhang. "In Situ Crosslinking Induced Structure Development and Mechanical Properties of Nano-Silica/Polypropylene Composites." Key Engineering Materials 334-335 (March 2007): 733–36. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.733.
In our previous works, a double percolation mechanism of stress volumes was proposed to explain the special effects generated by small amounts of grafted nanoparticles. Accordingly, it is inferred that strengthening nanoparticle agglomerates and enhancing nanoparticles/polymer matrix interfacial interaction are the key issues to improve mechanical performance of the matrix polymer. To confirm this idea, in-situ crosslinking was adopted to prepare nanocomposites by adding reactive monomers and crosslinking agents during melt compounding of nano-silica with polypropylene (PP). It was found that the grafted polymer chains were successfully crosslinked and chemically bonded to the nano-silica forming crosslinked networks. Meanwhile, matrix molecular chains penetrated through the networks to establish the so-called semi-IPN structure that interconnected nanoparticles by the networks and improved filler/matrix interfacial interaction. As a result, the tiny nanoparticles were well distributed in the matrix and the toughening and reinforcing effects of the nanoparticles on the matrix were brought into play at rather low filler loading, as evidenced by mechanical performance tests. Besides, β-crystal was detected in the nanocomposites experienced in-situ crosslinking reaction.
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Paramelle, David, Sergey Gorelik, Ye Liu, and Jatin Kumar. "Photothermally responsive gold nanoparticle conjugated polymer-grafted porous hollow silica nanocapsules." Chemical Communications 52, no. 64 (2016): 9897–900. http://dx.doi.org/10.1039/c6cc04187f.
We report a fabrication route of silica nanoparticles with two, three or six patches with an easily tunable patch-to-particle size ratio. The synthetic pathway includes two main stages: the synthesis of silica/polystyrene multipod-like templates and the selective growth of their silica core through an iterative approach. Electron microscopy of the dimpled nanoparticles obtained after dissolution of the polystyrene nodules of the multipod-like nanoparticles provides evidence of the conformational growth of the silica core. Thanks to the presence of some polymer chains, which remained grafted at the bottom of the dimples after the dissolution of the PS nodules, the solvent-induced assembly of the patchy nanoparticles is performed. Chains, hexagonal suprastructures and cubic lattices are obtained from the assembly of two-, three- and six-patch silica nanoparticles, respectively. Our study can guide future work in both patchy nanoparticle synthesis and self-assembly. It also opens new routes towards the fabrication of specific classes of one-, two- and three-dimensional colloidal lattices, including complex tilings.
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Yokoyama, Ruriko, Seiko Suzuki, Kumi Shirai, Takeshi Yamauchi, Norio Tsubokawa, and Makoto Tsuchimochi. "Preparation and properties of biocompatible polymer-grafted silica nanoparticle." European Polymer Journal 42, no. 12 (December 2006): 3221–29. http://dx.doi.org/10.1016/j.eurpolymj.2006.08.015.
Cellulose nanofibrils (CNFs) have attracted much attention because of their renewability and potential biocompatibility. However, CNFs are extremely hydrophilic due to the presence of a large number of hydroxyl groups, limiting their use as a water-resistant material. In this work, we controlled the adsorption behavior of silica nanoparticles on the surface of CNFs by adjusting the synthesis conditions. The silica nanoparticle size and packing efficiency on the CNF surface could be controlled by varying the ammonium hydroxide and water concentrations. In addition, hexadecyltrimethoxysilane (HDTMS) was successfully grafted onto CNF or CNF/silica nanocomposite surfaces, and the quantitative content of organic/inorganic substances in HDTMS was analyzed through XPS and TGA. The HDTMS-modified CNF/silica nanocomposites were more advantageous in terms of hydrophobicity than the HDTMS-modified CNF composites. This is because the silica nanoparticles were adsorbed on the surface of the CNFs, increasing the surface roughness and simultaneously increasing the amount of HDTMS. As a result, the HDTMS-modified CNFs showed a water contact angle (WCA) of ~80°, whereas HDTMS-modified CNF/silica nanocomposites obtained superhydrophobicity, with a WCA of up to ~159°. This study can provide a reference for the expansion of recyclable eco-friendly coating materials via the adsorption of silica nanoparticles and hydrophobic modification of CNF materials.
Dissertations / Theses on the topic "Grafted silica nanoparticle":
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Tang, Saide. "Self-Assembly of Polymer Brush-Grafted Silica Nanoparticles." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1451396345.
Issa, Sébastien. "Synthèse et caractérisation d'électrolytes solides hybrides pour les batteries au lithium métal." Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0046.
Les problématiques engendrées par l’extraction et l’utilisation intensives des ressources fossiles ont forcé l’humanité à se tourner vers le développement d’énergies renouvelables et de véhicules électriques. Cependant, ces technologies doivent être couplées à des moyens de stockage de l’énergie efficaces pour exploiter leur potentiel. Les systèmes embarquant une anode de lithium métallique sont particulièrement intéressants car ils présentent une densité d’énergie élevée. Cependant, cette technologie souffre de la formation de dendrites pouvant déclencher des courts-circuits provoquant l’explosion du dispositif. Ainsi, de nombreux efforts ont été consacrés à l’élaboration d’électrolytes solides polymères (SPE) à base de POE permettant de constituer une barrière qui bloque la croissance dendritique tout en préservant les propriétés de conduction ionique. Cependant, la conductivité ionique des SPE à base de POE décroît fortement avec la température. A l’heure actuelle, les meilleurs SPE de la littérature nécessiteraient de fonctionner à 60 °C, ce qui signifie qu’une partie de l’énergie de la batterie sera détournée de son utilisation pour maintenir cette température. Ainsi, l’objectif principal de ce travail de thèse est de concevoir un SPE permettant le fonctionnement de la technologie de batterie au lithium métal à température ambiante. Ces SPE doivent présenter une conductivité ionique élevée à température ambiante (≈ 10-4 S.cm-1) et des propriétés mécaniques permettant l’inhibition du phénomène de croissance dendritique. Pour cela, les objectifs du projet sont focalisés sur le développement de nouveaux SPE nanocomposites et hybrides The problems caused by the intensive extraction and use of fossil fuels have forced humanity to turn to the development of renewable energies and electric vehicles. However, these technologies need to be coupled with efficient energy storage means to exploit their potential. Lithium metal anode systems are particularly interesting because they have a high energy density. However, this technology suffers from the formation of dendrites that can trigger short circuits causing the device to explode. Thus, many efforts have been devoted to the development of POE-based solid polymer electrolytes (SPEs) that provide a barrier that blocks dendritic growth while preserving ionic conduction properties. However, the ionic conductivity of POE-based SPEs decreases strongly with temperature. Currently, the best SPEs in the literature would require operation at 60 °C, which means that some of the energy in the battery will be diverted from its use to maintain this temperature. Thus, the main objective of this thesis work is to design an SPE that allows the operation of lithium metal battery technology at room temperature. These SPEs must exhibit high ionic conductivity at room temperature (≈ 10-4 S.cm-1) and mechanical properties that allow the inhibition of the dendritic growth phenomenon. For this, the objectives of the project are focused on the development of new nanocomposite and hybrid SPEs
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Khlifa, Moussa Abrahim Saleh. "Synthesis of polymer grafted silica nanoparticles : effect of grafting on mechanical reinforcement." Thesis, Heriot-Watt University, 2013. http://hdl.handle.net/10399/2691.
A series of polymer-silica nanocomposites were prepared by grafting poly(methyl methacrylate), poly(butyl acrylate), polystyrene and poly(styrene-co-acrylonitrile) from both aggregated silica nanoparticles and colloidally dispersed silica using atom-transfer radical polymerisation (ATRP). Cross-linking and macroscopic gelation were minimised by using a miniemulsion system. The grafted polymers silica nanoparticles were characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), fourier transform infrared spectroscopy (FTIR) and elemental analysis. The thermal and mechanical behaviour of the nanocomposites have been examined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). Grafting polymers chains from the surface of the nanoparticles gave materials with a 10 oC higher glass transition temperature Tg (according to DSC and DMTA) compared to the pure polymers. DMTA measurements revealed that chain grafted nanocomposites showed an increased modulus and significantly lower high-temperature damping over the neat polymers. In contrast, samples prepared from colloidally dispersed silica nanoparticles exhibited a much less pronounced reinforcement effect than aggregated silica and also showed little change in Tg. Further information on the temperature dependence of the relaxation process was obtained using time temperature superposition. A fast and efficient microwave-assisted method for ring-deuteration of polystyrene and poly(4-hydroxystyrene) using “superheated” C6D6 or D2O in sealed microwave reaction vials has also been developed. The optimised procedure will make future work using neutron scattering possible.
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Samaratunga, Ashani Rangana. "Efficacy and Recovery of Cellulases Immobilized on Polymer Brushes Grafted on Silica Nanoparticles." Thesis, North Dakota State University, 2014. https://hdl.handle.net/10365/27212.
Cellulosic biofuels can be more economical if cellulases are recovered and reused.
Cellulase and ?-glucosidase were immobilized on poly(acrylic acid) brush particles. Impact of brush enzyme density on efficacy and recovery was tested. Use of free enzymes led to higher
sugar concentrations than the attached for both the enzymes. Increasing cellulase density on the
brushes did not impact efficacy. Higher proportions of cellobiose in hydrolyzates suggest
differential attachment or efficacy of attached enzymes. Higher ?-glucosidase density on brushes led to increased glucose concentrations. Density on brushes did not impact ?-glucosidase recovery and [approximately] 66% was recovered. Effect of pH and temperature on hydrolysis rates and enzyme recovery was modeled. Free ?-glucosidase was more stable with temperature than attached. Optimal pH for attached cellulase and ?-glucosidase was 4.98 and 4.39, respectively. Recovery of ?-glucosidase decreased with increasing pH and was not impacted by temperature. National Science Foundation (NSF)
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Fashina, Adedayo, Edith Amuhaya, and Tebello Nyokong. "Photophysical studies of newly derivatized mono substituted phthalocyanines grafted onto silica nanoparticles via click chemistry." Elsevier, 2015. http://hdl.handle.net/10962/d1020287.
This work reports on the synthesis, characterization and photophysical studies of newly derived phthalocyanine complexes and the phthalocyanine–silica nanoparticles conjugates. The derived phthalocyanine complexes have one terminal alkyne group. The derived phthalocyanine complexes showed improved photophysical properties (ФF, ФT, ΦΔ and τT) compared to the respective phthalocyanine complexes from which they were derived. The derived phthalocyanine complexes were conjugated to the surface of an azide functionalized silica nanoparticles via copper (1) catalyzed cyclo-addition reaction. All the conjugates showed lower triplet quantum yields ranging from 0.37 to 0.44 compared to the free phthalocyanine complexes. The triplet lifetimes ranged from 352 to 484 μs for the conjugates and from 341 to 366 μs for the free phthalocyanine complexes.
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Duda, Radek. "Analýza nanostruktur metodou ToF-LEIS." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-234584.
The presented thesis deals with the utilization of TOF-LEIS analytical method in the area of nanostructure analysis. A new procedure for depth profiling of the elemental composition of the sample, based on the alternate measurement with the DSIMS method, was established. The TOF-LEIS method is able to detect the interface between the layers before its mixing by the ion beam of the DSIMS method. Furthermore, a procedure of TOF-LEIS spektra modification was established to obtain the actual concentration of elements in the sample by reduction of a multiple collision contribution. By comparison of TOF-LEIS spectra with the results received by the DSIMS method the ratio of molybdenum and silicon ion yields was obtained. In the next section advantages of the TOF-LEIS method in combination with XPS during analysis of thermal stability of gold nanoparticles are presented. The mutual complementarity of both methods is shown and final conclusions are supported by electron microscopy images. The final section deals with a newly assembled apparatus for the TOF-SARS analytical method and shows its possibilities regarding the detection of hydrogen on the graphene.
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Huang, Hao-Kuan, and 黃豪寬. "Synthesis of nano-scale colloidal silica from elemental silicon by hydrolysis, and synthesis of polymer-grafted silica nanoparticle, polymer-grafted graphene oxide, and polymer-grafted exfoliated graphene nanoplatelet with core-shell structure as low-profile additives and tougheners for unsaturated polyester and vinyl ester resins by RAFT living free radical solution polymerizations." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/29945158148023952847.
碩士 國立臺灣科技大學 化學工程系 103 Synthesis of nano-scale inorganic/organic core-shell particle (CSP) as low-profile additives (LPA) and toughenors for thermoset resins, and their effects on the cured sample morphology, volume shrinkage characteristics and mechanical properties for low-shrink vinyl ester resins (VER) during the cure were investigated.
These CSP designated as SiO2-polymer or GO-polymer, the former of which contained silica nanoparticle (SNP) as the core and the latter of which contained graphite oxide(GO) as the cure and both of them with organic polymer as the shell, were synthesized by the Z supported reversible addition-fragmentation chain transfer (RAFT) graft polymerization using silica-supported or graphite oxide-supported 3-(benzylsulfanylthiocarbonylsulf- anl) propionic acid (SiO2-BSPA or GO-BSPA) as the chain transfer agent (CTA). The silica nanoparticle with a diameter of 15 nm was synthesized by size-controllable hydrolysis of elemental silicon, and the graphite oxide(GO) was synthesized from natural graphites with average particle size of 2 to 15μm. The grafted polymer as the shell of the SiO2-polymer or GO-polymer was made from poly(methyl acrylate)(PMA), copolymer of MA and glycidyl methacrylate(poly(MA-co-GMA)),poly(butylacrylate)-block-poly(methyl acrylate) (PBA-b-PMA) or PBA-block-poly(MA-co-GMA).
Structure characterizations of BSPA, SiO2-BSPA, SiO2-polymer, GO-BSPA and GO-polymer have been performed by using FTIR, 1H-NMR, 13C-NMR, GPC and DSC. In this work, the effects of SiO2-polymer and GO-polymer on the volume shrinkage characteristics and mechanical properties of the styrene(St)/ vinyl ester(VER)/ SiO2-polymer or (GO-polymer) ternary systems during the cure have also been explored.
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Chung, Wan-lun, and 鍾宛倫. "Synthesis of nano-scale colloidal silica from elemental silicon by hydrolysis, and synthesis of polymer-grafted silica nanoparticle and polymer-grafted monomorillonite clay with core-shell structure as low-profile additives and tougheners for unsaturated polyester, vinyl ester, and epoxy resins by RAFT living free radical solution polymerizations." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/58613975785769985529.
碩士 國立臺灣科技大學 化學工程系 102 Synthesis of nano-scale inorganic/organic core-shell particle (CSP) as low-profile additives (LPA) and toughenors for thermoset resins, and their effects on the cured sample morphology, volume shrinkage characteristics and mechanical properties for low-shrink vinyl ester resins (VER) during the cure were investigated. These CSP designated as SiO2-polymer, which contained silica nanoparticle (SNP) as the core and organic polymer as the shell, were synthesized by the Z supported reversible addition-fragmentation chain transfer (RAFT) graft polymerization using silica-supported 3-(benzylsulfanylthiocarbonylsulf- anl) propionic acid (Si-BSPA) as the chain transfer agent (CTA). The silica nanoparticle with a diameter of 15 nm was synthesized by size-controllable hydrolysis of elemental silicon, whereas the grafted polymer as the shell of the SiO2-polymer was made from poly(methyl acrylate) (PMA), copolymer of MA and glycidyl methacrylate (poly(MA-co-GMA)), poly(butyl acrylate)-block-poly(methyl acrylate) (PBA-b-PMA) or PBA-block-poly(MA-co-GMA).
Depending on the molecular weight of the VER resin matrix employed, the content of CSP, and the shell composition of CSP, the CSP could lead to a reduction of cyclization reaction for VER resins during the cure, and the microgel structure during the cure would be less compact, and, in turn, be favorable for the decrease of intrinsic polymerization shrinkage after the cure. It was found that with the adjustment of VER molecular weight to prevent the phase separation of the St/VER/SiO2-polymer ternary system prior to cure, adding a higher content of SiO2-polymer as an LPA in the VER resin may result in a lower volume shrinkage after cure, and adding 10% of 15 nm size of SiO2- polymer can lead to a decrease of volume shrinkage by 80%. Also, adding 10% of 15 nm size of SiO2- polymer can result in an increase of impact strength and Young’s modulus, by 80% and 25%, respectively, but a decrease of tensile strength by 30%.
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Lin, Hsiao-chien, and 林曉倩. "Nitroxide Polymer Brushes Grafted onto Silica Nanoparticles as Cathodes for Organic Radical Batteries." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/80141698288157113057.
碩士 國立中山大學 化學系研究所 100 Nitroxide polymer brushes grafted on silica nanoparticles as binder-free cathode for organic radical battery have been investigated. Scanning electron microscopy, transmission electron microscopy, infrared spectroscopy and electron spin resonance confirm that the nitroxide polymer brushes are successfully grafted onto silica nanoparticles via surface-initiated atom transfer radical polymerization. The thermogravimetric analysis results indicate that the onset decomposition temperature of these nitroxide polymer brushes is found to be ca. 201 ◦C. The grafting density of the nitroxide polymer brushes grafted on silica nanoparticles is 0.74–1.01 chains nm−2.
The results of the electrochemical quartz crystal microbalance indicate that the non-crosslinking nitroxide polymer brushes prevent the polymer from dissolving into organic electrolytes. Furthermore, the electrochemical results show that the discharge capacity of the polymer brushes is 84.9–111.1 mAh g−1 at 10 C and the cells with the nitroxide polymer brush electrodes have a very good cycle-life performance of 96.3% retention after 300 cycles.
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Yang, Jian-jhe, and 楊建哲. "Synthesis and applications of nitroxide radical polymer brushes grafted onto silica nanoparticles and Fe3O4@SiO2 core-shell nanoparticles." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/88968600508672208541.
碩士 國立中山大學 化學系研究所 100 Nitroxide radical groups grafted on silica have been synthesized. The catalytic oxidation of alcohols to aldehydes and ketones using the nitroxide radical groups as a catalyst was also investigated. The results of scanning electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy confirmed that the nitroxide radical groups are successfully grafted onto silica. The yield of the catalytic oxidation using the catalysts is higher than 99%. The catalysts are easily recovered. Furthermore, the reused catalysts still keep high performance in the catalytic oxidation.
Book chapters on the topic "Grafted silica nanoparticle":
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Cai, Li Feng, Min Zhi Rong, Ming Qiu Zhang, and Wen Hong Ruan. "Graft Polymerization of p-Vinylphenylsulfonylhydrazide onto Nano-Silica and its Effect on Dispersion of the Nanoparticles in Polymer Matrix." In Advances in Composite Materials and Structures, 729–32. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-427-8.729.
Conference papers on the topic "Grafted silica nanoparticle":
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Holzworth, Kristin, Gregory Williams, Bedri Arman, Zhibin Guan, Gaurav Arya, and Sia Nemat-Nasser. "Polyurea With Hybrid Polymer Grafted Nanoparticles: A Parametric Study." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88395.
The basis of this research is to mitigate shock through material design. In this work, we seek to develop an understanding of parametric variations in polyurea-based nano-composite materials through experimental characterization and computational modeling. Blast-mitigating applications often utilize polyurea due to its excellent thermo-mechanical properties. Polyurea is a microphase-separated segmented block copolymer formed by the rapid reaction of an isocyanate component and an amine component. Block copolymers exhibit unique properties as a result of their phase-separated morphology, which restricts dissimilar block components to microscopic length scales. The soft segments form a continuous matrix reinforced by the hard segments that are randomly dispersed as microdomains. The physical properties of the separate phases influence the overall properties of the polyurea. While polyurea offers a useful starting point, control over crystallite size and morphology is limited. For compositing, the blending approach allows superb control of particle size, shape, and density; however, the hard/soft interface is typically weak for simple blends. Here, we overcome this issue by developing hybrid polymer grafted nanoparticles, which have adjustable exposed functionality to control both their spatial distribution and interface. These nano-particles have tethered polymer chains that can interact with their surrounding environment and provide a method to control well defined and enhanced nano-composites. This approach allows us to adjust a number of variables related to the hybrid polymer grafted nanoparticles including: core size and shape, core material, polymer chain length, polymer chain density, and monomer type. In this work, we embark on a parametric study focusing on the effect of silica nanoparticle size, polymer chain length, and polymer chain density. Preliminary results from experimental characterization and computational modeling indicate that the dynamic mechanical properties of the material can be significantly altered through such parametric modifications. These efforts are part of an ongoing initiative to develop elastomeric composites with optimally designed compositions and characteristics to manage blast-induced stress-wave energy.
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Razali, Norzafirah, Ivy Ching Hsia Chai, Arif Azhan A Manap, and M. Iqbal Mahamad Amir. "Enhanced Foam Stability Using Nanoparticle in High Salinity High Temperature Condition for Eor Application." In Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/208196-ms.
Abstract The capability of commercial nanoparticles to perform as foam stabilizer were investigated at reservoir temperature of 96°C. Al2O3, Fe3O4, Co3O4, CuO, MgO, NiO, ZrO2, ZnO and SiO2 nanoparticles that were characterized using XRD, FTIR, FESEM-EDX, TEM and PSA, were blended in the in-house formulated surfactant named IVF respectively at a particular ratio. The test was performed with and without the presence of reservoir crude oil. Results showed that formulation with nanoparticles enhanced foam stability by having longer foam half-life than the IVF surfactant alone, especially in the absence of oil. Only SiO2 nanoparticles were observed to have improved the foam stability in both test conditions. The unique properties of SiO2 as a semi-metal oxide material may have contributed to the insensitivity of SiO2 nanoparticle towards crude oil which is known as a foam destabilizer. The physical barrier that was formed by SiO2 nanoparticles at the foam lamella were probably unaffected by the presence of crude oil, thus allowing the foams to maintain its stability. In thermal stability tests, we observed the instability of all nanoparticles in the IVF formulation at 96°C. Nanoparticles were observed to have separated and settled within 24 hours. Therefore, surface modification of nanoparticle was done to establish steric stabilization by grafting macro-molecule of polymer onto the surface of SiO2. This in-house developed polymer grafted silica nanoparticles are named ZPG nanoparticles. The ZPG nanoparticles passed the thermal stability test at 96°C for a duration of 3 months. In the foam wetness analysis, ZPG nanoparticles were observed to have produced more wet foams than IVF formulation alone, indicating that ZPG is suitable to be used as foam stabilizer for EOR process as it showed catalytic behaviour and thermally well-stable at reservoir temperature.
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Hatchell, Daniel, Wen Song, and Hugh Daigle. "Effect of Inter-Particle Van Der Waals Attraction on the Stability of Pickering Emulsions in Brine." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206112-ms.
Abstract Pickering emulsions are stabilized by solid particles that occupy the fluid-fluid interface, physically preventing coalescence. Their stability in brine, where interparticle electrostatic repulsion is negligible and van der Waals (vdW) attraction dominates, makes them attractive for applications in porous media. Recent studies postulate that inter-droplet particle networks assemble in brine and aid Pickering emulsion stability to coalescence. This work experimentally assesses the effect of increasing interparticle vdW attraction on particle network strength and emulsion stability. We grafted 6 nm, 12 nm, and 20 nm silica nanoparticles with varying densities of polyethylene glycol (PEG) to prevent aggregation and dispersed them in either brine or deionized water (DI). We characterized the PEG-coated nanoparticles with thermogravimetric analysis and dynamic light scattering to determine PEG grafting density, diameter, and zeta potential. To generate oil-in-water emulsions, we sonicated dispersions of variable nanoparticle concentration and decane in equal volumes. We imaged the emulsions with microscopy and centrifuged them for 15 minutes at 5000 g of acceleration, using the volume of decane released after centrifugation as a measurement of emulsion coalescence to the applied force. Nanoparticle characterization confirmed successful grafting of PEG to the silica surface. We compared trends in emulsion stability as a function of salinity and particle diameter to changes in the relevant interparticle forces described by extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Analysis of microscopy images showed an increase in emulsion droplet diameter with decreasing nanoparticle concentration, salinity, and increasing nanoparticle diameter. Through centrifugation we observed that lower PEG grafting densities tended to produce more stable emulsions, suggesting that particles with high grafting densities and consequently high steric repulsion tended to repel and prevent formation of strong particle networks. Emulsions generated in DI coalesced more easily, indicating that electrostatic repulsion dominated relative to vdW attraction and that particle networks did not form. In brine, where electrostatic forces were screened out by counterions, the emulsions better resisted coalescence, consistent with the formation of a particle network. The strength of the network was inferred from the difference in emulsion stability to coalescence in DI and in brine. We measured a greater brine-DI stability difference of 3.7× for the larger 20 nm PEG-coated nanoparticles, compared with 3.3× and 2.2× for the 12 nm and 6 nm PEG-coated particles, respectively, further supporting the role of particle networks on emulsion stability.
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Huang, Xingyi, Yahan Gao, and Pingkai Jiang. "Voltage Stabilizer Grafted Silica Nanoparticles for Significantly Enhanced Breakdown Strength Potential Thermoplastic Polypropylene Insulation." In 2019 2nd International Conference on Electrical Materials and Power Equipment (ICEMPE). IEEE, 2019. http://dx.doi.org/10.1109/icempe.2019.8727303.
Zhi, Suo-Hong, Bo Zhang, Yun Wang, Yun-Lian Zhang, Guo-Jun Zhou, Ran Deng, Ling-Shu Wan, and Zhi-Kang Xu. "Composite Nanofiltration Membranes from Polyacrylonitrile and Poly (N, N-Dimethylaminoethyl Methacrylate)-Grafted Silica Nanoparticles." In 2016 International Conference on Mechanics and Materials Science (MMS2016). WORLD SCIENTIFIC, 2017. http://dx.doi.org/10.1142/9789813228177_0111.
Wu, Feng, Zhengying Liu, and Mingbo Yang. "The study of poly(L-lactide) grafted silica nanoparticles on the film blowing of poly(L-lactide)." In PROCEEDINGS OF PPS-30: The 30th International Conference of the Polymer Processing Society – Conference Papers. AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4918455.
Li, Houbin, Xiaohui Zhang, Wenjuan Gu, Xiaohui Zhang, Shengping Yi, and Chi Huang. "The Preparation and Characterization of a Compatibilizer: Silicon Dioxide Nanoparticles Grafted with L-Lactic Acid Oligomer." In 2008 International Conference on Computer Science and Software Engineering. IEEE, 2008. http://dx.doi.org/10.1109/csse.2008.603.
Hendraningrat, Luky, Norzafirah Razali, and Raj Deo Tewari. "Novel Mechanism Investigation during Development of Nanofluids to Improve Oil Recovery in Malaysian Oilfield." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-22310-ea.
Abstract The nanoparticles are considered as an attractive emerging improved oil recovery technique in last decade due to its ability to propagate deeper into pore throat and displace unswept oil in the reservoir. Current understanding of its mechanisms in conventional oil has been observed so called disjoining pressure that involved wettability alteration, log-jamming, and viscosity effect. This paper presents recent investigation of new potential mechanism during development of nanofluids to improve oil recovery in Malaysian oilfield. The new inhouse nanofluids was developed using acrylamide monomers that were grafted on the surface of silica-based nanoparticles. A minor concentration of surfactant was introduced into the formulation to observe synergistic effect. The nanoparticles were characterized under electron microscope. Compatibility and thermal stability tests were conducted using reservoir fluids at reservoir temperature. The rheology of fluids was measured during monitoring of stability. In term of wettability alteration, sequence fluid-fluid and rock-fluid tests were conducted includes dynamic interfacial tension (IFT) and optical contact angle (OCA) measurement. The particle size was measured with size around 20 nm. Adding small concentration of additive showed good performance in term of compatibility, thermal stability, and wettability alteration through IFT reduction and OCA measurement. Nanofluids with additive provided excellent compatibility with reservoir fluids and stable at reservoir temperature over 60 days. Its viscosity was also more stable during observation period without creating micro-emulsion. The IFT reduced insignificantly from 2.6 to 1 mN/m and when introduced additive, the IFT reduction achieved 0.01 mN/m. This synergistic effect was observed during IFT measurement and called as fragmentation. Our recent finding leads to provide new reference for displacement mechanism using next generation of nanofluids and offers further potential of nanoparticles with multiple mechanisms and rapid synergistic effects prior its application in in Malaysian oilfield.
