Scientific Reports (20452322)15(1)
Epoxy adhesives are widely used as structural adhesives distinguished by a significant degree of cross-linking, resulting in their brittle characteristics. Some specialized applications require improved thermal stability and adhesive strength. The incorporation of zinc oxide nanoparticles into a core–shell rubber (CSR) structure composed of poly(butyl acrylate-allyl methacrylate) core and poly(methyl methacrylate-glycidyl methacrylate) shell will enhance the adhesion, toughness, and thermal stability of epoxy adhesives. We synthesized CSR particles using a two-stage emulsion polymerization method, characterizing them through Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) analyses. We synthesized epoxy adhesives with different CSR particles ratios (1.25, 2.5, and 3.75 phr) and zinc oxide nanoparticles (1, 2, and 5 phr) using mechanical stirring and ultrasonication (a two-step mixing process) to enhance dispersion. We cured the epoxy adhesive samples for 7 days for tensile tests and 2 days for lap shear tests at room temperature. We employed the tensile and lap shear tests to assess the mechanical properties of the samples. The samples underwent thermogravimetric analysis (TGA) to assess their thermal stability. We assessed the fracture surface of the optimum samples using field-emission scanning electron microscopy (FESEM). We utilized design-of-experiments (DOE) and artificial neural network (ANN) approaches to model the mechanical properties. The outcomes of FTIR, SEM, TEM and DCS analyses validated the successful synthesis of CSR particles. The tensile test findings on the dumbbell-shaped samples show a 51%, 30%, and 218% enhancement in tensile strength, modulus, and toughness for the samples containing 2.5 phr CSR particles and 2 phr zinc oxide nanoparticles, respectively. Furthermore, the lap shear tests revealed that the addition of 3.75 phr CSR particles and 5 phr zinc oxide nanoparticles increased the shear strength to 19.5 MPa. This is 127% higher than the pure epoxy. The TGA data indicated that both additions improved the thermal stability of the pure epoxy. Additionally, the predictions of shear strength, toughness, tensile modulus, and tensile strength by DOE and ANN were very close to the experimental results (R2adj > 0.95 for DOE and MREave < 3.2 for ANN). © The Author(s) 2025.
Progress in Organic Coatings (03009440)186
This study presents a novel method to create a UV-curable nanocomposite coating composed of fluorinated polyurethane acrylate (FPUA) and modified graphene oxide (MGO) with exceptional corrosion resistance. The graphene oxide (GO) nanosheets were chemically modified with methacryloxy propyl trimethoxy silane to improve their dispersibility and interactions with the FPUA resin, which was used as the matrix of the prepared coatings. The modification was verified by various techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Different amounts of MGO were added to the FPUA resin to prepare the UV-curable coatings. The physicochemical interactions between the MGO and the binder were investigated by measuring the gel contents, adhesion strength, and thermal stability of the coatings. The corrosion resistance of the nanocomposite was assessed by different methods, and the results showed that adding 2 wt% MGO reduced the film porosity by more than six orders of magnitude. The results also indicated a significant improvement in the resistance to ionic current and charge transfer due to the good dispersion, barrier properties, and strong bonding of the MGO with the polymer matrix. Nevertheless, the excessive loading of MGO could potentially harm the anticorrosion properties of the coating by forming aggregates and corrosive elements diffusion routes. The obtained results revealed that the prepared UV-curable nanocomposite coatings could open up a new avenue for designing anticorrosive nanocomposite coatings based on graphite derivatives. © 2023
Lin P.,
Basem, A.,
Alizadeh, A.,
Nasser E.N.,
Al-bahrani, M.,
Chan C.K.,
Emami n., N.,
Village, A.,
Pourghasem, M. Case Studies in Thermal Engineering (2214157X)pp. 3312-3322
The initial temperature has a considerable effect on aluminum polycrystals' physical stability and mechanical performance, with the possibility to optimize their mechanical properties for practical applications. Thus, using a molecular dynamics technique, the effect of temperature on the mechanical properties of aluminum polycrystals is studied. Stress-strain curves, ultimate strength, and Young's modulus were all measured at temperatures of 300, 350, 400, and 450 K. The findings from MD simulations show that the initial temperature significantly affects the physical stability and mechanical performance of designed aluminum polycrystals. The aluminum polycrystal experiences a numerical increase in ultimate strength and Young's modulus from 6640 to 74.072 to 7.055 and 79.226 GPa, respectively, when subjected to the optimal initial conditions of 350 K. With further increasing temperature to 450 K, ultimate strength and Young's modulus decrease to 6.461 and 74.413 GPa, respectively. The observed decrease in ultimate strength and Young's modulus of the aluminum polycrystal as the temperature increased from the optimal condition of 350 K–450 K can be attributed to the weakening of interatomic attraction forces at higher temperatures. This reduction in interatomic bonding strength resulted in decreased material stiffness and resistance to deformation, leading to lower ultimate strength and Young's modulus values. This study's novelty lies in its comprehensive assessment of the initial temperature's effects on the mechanical performance of aluminum polycrystals, providing valuable insights for practical applications and advancing beyond previous efforts in the literature. © 2024 The Authors
Asgari S.,
Khodabakhshi A.R.,
Rasouli A.,
Sahabi M.,
Karimian R.,
Village, A.,
Abdollahi, A.,
Sohrabi, L. Colloids and Interface Science Communications (22150382)pp. 646-654
Excessive use of pesticides and therefore the spread of pesticides in the environment with destructive effects on human and animal health is a very great problem in the world. In this study, the removal of three samples of organochlorine pesticides including aldrin, lindane, and endosulfan was investigated using nanofiltration membranes modified with NH2-MWCNTs. The properties of the prepared membranes were investigated by scanning electron microscopy (SEM), contact angle, water content, porosity, and mechanical strength. The performance of the membranes was evaluated by analysis of the rejection and flux of pesticide solutions at different pH. The addition of NH2-MWCNTs to the polymer matrix significantly improved the hydrophilic properties of the membranes and reduced the contact angle. Membrane flux was also improved by increasing the concentration of carbon nanotubes to 0.2 wt%. The highest flux at pH 10 is related to lindane pesticide. The modified membrane with 0.5 wt% functionalized carbon nanotubes showed a 98% rejection for endosulfan at neutral pH compared to the pure membrane. In the pH range experiment, lindane rejection was lower than of other pesticides. The steric hindrance due to the structure and molecular size of pesticides and interaction with membrane surface was very important in membrane efficiency. The M3 membrane with 0.3 wt% NH2-MWCNTs revealed high antifouling performance. © 2024 The Authors
Progress in Organic Coatings (03009440)189
Successfully synthesized polymerizable nanoflakes composed of acrylated polyaniline (Ac-PANI)/graphene oxide (GO) demonstrate synergistic corrosion resistance enhancement. Comprehensive analyses of the chemical composition, thermal stability, and surface morphology of the Ac-PANI/GO (PGO) nanoflakes were conducted using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis (TGA). Subsequently, varying amounts of the prepared PGO were employed to enhance the anti-corrosion performance of the environmentally friendly UV-cured polyurethane matrix. Physico-mechanical properties of the coatings were evaluated through dynamic mechanical thermal analysis, TGA, gel content measurement, and adhesion strength tests. Incorporating 2 wt% PGO resulted in a significant improvement in cross-link density, thermal stability, adhesion strength, and modulus compared to the pure polymer coating. The anti-corrosion performance of the nanoflake filler in both the solution phase and within the coating matrix was demonstrated through electrochemical impedance spectroscopy and polarization tests. The results indicated substantial corrosion mitigation in both states. Under optimal conditions with 2 % wt PGO, impedance values increased by over two orders of magnitude compared to the pure polymer coating. Even after 50 days of immersion, the coating with 2 wt% PGO maintained a high impedance of 1.11 × 109 Ω.cm2, surpassing other coatings. This exceptional anti-corrosion performance was attributed to the synergistic effect of the excellent barrier properties resulting from well-dispersed PGO in the UV-cured polymer matrix and the formation of a passive metal oxide layer induced by the polymerizable Ac-PANI present in the composition of the PGO nanocomposite. © 2024
Polymers for Advanced Technologies (10427147)34(2)pp. 646-654
Counterfeiting is an ever-growing global problem challenging companies, governments, and customers. In recent decades, as a potential remedy, anticounterfeiting technology and information security have gained a great deal of attention from academia and industry. In this work and for the first time, Rhodamine B (RhB), an efficient and enticing fluorescent material, was modified and used as a reactive stimuli-responsive component in the formulation of an eco-friendly ink. Additionally, a UV-curable polyurethane dispersion (UCPUD) with zero volatile organic compound was synthesized and employed as the matrix for the fluorescent ink. The modified RhB and UCPUD were thoroughly characterized using Fourier-transform infrared and proton nuclear magnetic resonance analyses. Exploiting the fluorescent monomer in the ink formulations could enhance the absorption intensity (λmax = 552 nm) of the prepared ink up to 7 with respect to its solution (λmax = 519 nm). The printed pattern was immediately illuminated with brilliant red-pink fluorescence emission upon UV irradiation. It has been shown that the prepared fluorescent ink has potential applications in the encryption, security marking, and optical authentication of confidential cellulose substrates. © 2022 John Wiley & Sons Ltd.
Langmuir (15205827)39(14)pp. 5115-5128
In this study, 2-acrylamido-2-methylpropanesulfonic acid (AMPS)-doped polyaniline (PANI) fibers were used as polymerizable smart anticorrosive agents to prepare eco-friendly UV-curable anticorrosive coatings. For this purpose, AMPS-doped PANI fibers were synthesized through chemical oxidative interfacial polymerization. The size and chemical structure of the prepared conducting fibers were characterized by scanning electron microscopy, 1H NMR, and Fourier transform infrared (FTIR) analyses. As a binder for the prepared conducting fibers, an eco-friendly fluorinated urethane-methacrylate dispersion was synthesized and fully characterized using FTIR analysis. Subsequently, various amounts of the synthesized fibers were mixed with the fluorinated binder to prepare UV-curable anticorrosive coatings. The physicochemical interactions between the PANI fibers and UV-curable binder were studied thoroughly using differential scanning calorimetry and thermogravimetric analyses and measurement of the gel contents and adhesion strength of the prepared composite coatings. The corrosion resistance performance of the prepared coatings was evaluated using electrochemical impedance spectroscopy analysis, and the obtained results revealed that the presence of 2 wt % of the AMPS-doped PANI fibers significantly enhanced the corrosion resistance of the obtained coating. In addition, the corrosion layers of the coatings were analyzed using X-ray photoelectron spectroscopy, which indicated that the AMPS-doped PANI fibers changed the composition of the corrosion product layer. To expand these attempts, this study also explores the interaction of AMPS-doped PANI fibers with the Fe(100) surface using density functional theory as well as atom in molecule calculations. All of the obtained results proved that the outstanding corrosion protection performance of the prepared composite coatings originated from exceptional chemical interactions between the unsaturated doping agents of the prepared PANI fibers and the UV-cured polymer. © 2023 American Chemical Society.
Polymers for Advanced Technologies (10427147)33(10)pp. 3312-3322
Herein, a facile, scalable, and cost-effective method was used to fabricate eco-friendly superhydrophobic UV-curable polyurethane-silica nanocomposite coating with promising physicomechanical properties. Fluorinated UV-curable polyurethane dispersion was synthesized and used as the binder of the superhydrophobic coating along with hydrophobically modified silica nanoparticles as textured topography. The chemical structures of the employed silica nanoparticles, prepared UV-curable polymer, and superhydrophobic coating were thoroughly studied by FTIR analysis. It has been revealed that the prepared SH coating possesses well-defined micro/nano-scale roughness, high contact angle (159°), and low sliding angle (1.5°), which can be applied onto various substrates. Also, the exceptional durability of the fabricated coating against sandpaper abrasion (over 80 m) without losing its superhydrophobicity revealed the high capability of the prepared waterborne coating to be used in harsh practical applications. Additionally, due to the highly cross-linked structure of the prepared SH coating, the applied coating could maintain its integrity even after 30 days of immersion in different organic solvents. Moreover, the prepared coatings showed substantial potential for use in self-cleaning and oil/water separation fields (> 98% efficiency after 15 cycles of oil/water separations). We are convinced that the prepared hybrid coating could offer a practical approach for fabricating of superhydrophobic materials as promising nominates for disparate fields. © 2022 John Wiley & Sons Ltd.
Scientific Reports (20452322)11(1)
Here, core–shell impact modifier particles (CSIMPs) and multiwalled carbon nanotubes (MWCNs) were used as reinforcing agents for improving the toughness and tensile properties of epoxy resin. For this purpose, emulsion polymerization technique was exploited to fabricate poly(butyl acrylate-allyl methacrylate) core-poly(methyl methacrylate-glycidyl methacrylate) shell impact modifier particles with an average particle size of 407 nm. It was revealed that using a combination of the prepared CSIMPs and MWCNTs could significantly enhance the toughness and tensile properties of the epoxy resin. Also, it was observed that the dominant factors for improving the fracture toughness of the ternary composites are crack deflection/arresting as well as enlarged plastic deformation around the growing crack tip induced by the combination of rigid and soft particles. The Response Surface Methodology (RSM) with central composite design (CCD) was utilized to study the effects of the amounts of CSIMPs and MWCNTs on the physicomechanical properties of the epoxy resin. The proposed quadratic models were in accordance with the experimental results with correlation coefficient more than 98%. The optimum condition for maximum toughness, elastic modulus, and tensile strength was 3 wt% MWCNT and 1.03 wt% CSIMPs. The sample fabricated in the optimal condition indicated toughness, elastic modulus, and tensile strength equal to 2.2 MPa m1/2, 3014.5 MPa, and 40.6 MPa, respectively. © 2021, The Author(s).
Najafipour, A.,
Village, A.,
Fassihi, A.,
Sadeghi-aliabadi, H.,
Mahdavian, A.R. Molecular Pharmaceutics (15438384)18(1)pp. 275-284
In recent years, the exploitation of magnetic nanoparticles in smart polymeric matrices have received increased attention in several fields as site-specific drug delivery systems. Here, ultrasonic-assisted emulsion copolymerization of N-isopropylacrylamide (NIPAM) and 2-(N,N-diethylaminoethyl) methacrylate (DEAEMA) in the presence of Fe3O4 nanoparticles was employed to prepare pH- and temperature-responsive magnetite nanocomposite particles (MNCPs). The obtained MNCPs were fully characterized by TEM, DSC, FT-IR, VSM, and XRD techniques. They had an average particle size of 70 nm with a lower critical solution temperature of 42 °C and superparamagnetic properties. In addition, MNCPs were loaded with methotrexate (MTX) as an anticancer drug, and their in vitro drug release was studied in different pH values and temperatures and in the presence of an alternating magnetic field. Noteworthy that the highest rate of MTX release was observed at pH 5.5 and 42 °C. Cell viability of the treated MCF-7 human breast cancer cell line with free MTX, MNCPs, and MTX-loaded MNCPs or in combination with magnetic hyperthermia (MHT) and water-based hyperthermia was comparatively studied. The obtained results showed about 17% higher antiproliferative activity for the MTX-loaded MNCPs accompanied by MHT relative to that of free MTX. © 2020 American Chemical Society.
ACS Applied Polymer Materials (26376105)3(8)pp. 4008-4016
To take full advantage of the synergistic effects of soft organic and rigid inorganic toughening agents, elastomeric core/amine-functionalized silica shell armored nanocomposite particles were prepared through Pickering emulsion polymerization. The size and microstructure of the prepared armored impact modifier particles (AIMPs) were studied thoroughly. It was substantiated that the amine-functional silica nanoparticles have been successfully attached to the surface of the colloidal polymer particles. The obtained results revealed that the incorporation of the prepared AIMPs into epoxy resin could exert significant positive influences on its toughness, tensile strength, and modulus. An optimal content of AIMPs was found to exist, which enhanced the fracture toughness by 8 times, the fracture energy by 50 times, and the tensile strength by 38% for the modified sample using 7 wt % AIMPs in comparison with those of the neat epoxy resin. The primary toughening mechanisms were related to crack pinning and deflection as well as deboning of AIMPs from the epoxy matrix followed by plastic void growth. © 2021 American Chemical Society.
Advances in Colloid and Interface Science (00018686)269pp. 152-186
In recent years, polymer nanoparticles (PNPs) have found their ways into numerous applications extending from electronics to photonics, conducting materials to sensors and medicine to biotechnology. Physical properties and surface morphology of PNPs are the most important parameters that significantly affect on their exploitations and can be controlled through the synthesis process. Emulsion and miniemulsion techniques are among the most efficient and wide-spread methods for preparation of PNPs. The objective of this review is to present and highlight the recent developments in the advanced PNPs with specific properties that are produced through emulsion and miniemulsion processes. © 2019 Elsevier B.V.
Journal of Coatings Technology and Research (15470091)16(3)pp. 781-789
Here, waterborne coatings with enhanced physico-mechanical properties were prepared by incorporation of modified silica nanoparticles into an acrylic matrix through miniemulsion polymerization. In order to circumvent the inherent incompatibility of organic and inorganic portions, methylene diphenyl diisocyanate and 2-hydroxyethyl methacrylate molecules were chemically coupled to the surface of silica nanoparticles to alter the hydrophilic nature of inorganic nanoparticles to hydrophobic ones. Also, for investigating the effect of the exploited surface modification process, unmodified silica nanoparticles were used in preparing acrylic latex via miniemulsion polymerization. The optical and physico-mechanical properties of the acrylic–silica nanocomposite films with 0–10 wt% of unmodified and modified SiO 2 were characterized by measuring their surface roughness, haziness, gloss values, UV–Vis transmittance, scratch resistance, tensile, and pendulum hardness. It was found that by using modified SiO 2 nanoparticles, due to their better dispersion state and ability for establishing covalent linkage with acrylic polymer chains, it is possible to obtain nanocomposite coatings with improved physico-mechanical properties, high transparency in Vis region, considerable UV adsorption, and comparable surface roughness, glossiness, and haziness with pure acrylic film. However, unmodified silica nanoparticles formed many aggregates in the polymer matrix which deteriorated optical and different physico-mechanical properties of acrylic latex. It was found that the greatest improvement in properties is achieved by incorporation of 7 wt% modified silica nanoparticles in acrylic polymer. © 2019, American Coatings Association.
Polymer (00323861)98pp. 182-189
Hybrid latex particles with core-shell nanostructure were prepared via miniemulsion polymerization. Copolymer of (methyl methacrylate-butyl acrylate-methacrylic acid) was formed the shell on the surface of modified SiO2 nanoparticles as the core. In order to create compatibility between inorganic and polymeric phases, modification of SiO2 nanoparticles was performed with methylene diphenyl diisocyanate and 2-hydroxy ethyl methacrylate with an optimized procedure for the first time, and then miniemulsion polymerization was carried out in the presence of modified SiO2. The products of each step were characterized. The results of DLS, TEM and SEM analyses proved the formation of encapsulated hybrid latex particles. DLS and SEM data revealed that the sizes of nanocomposite particles vary between 60 and 120 nm for 0-10 wt% of the modified SiO2 nanoparticles. Thermal stability and thermo-mechanical properties of the obtained nanocomposite films were studied by TGA and DMTA, respectively. It was found that the best improvement of properties is achieved for nanocomposite containing 7 wt% modified silica nanoparticles. © 2016 Elsevier Ltd.
Iranian Polymer Journal (10261265)25(12)pp. 991-998
An antistatic and electrically conductive acrylic–polyaniline nanocomposite coating was successfully synthesized by interfacial polymerization of aniline in the presence of acrylic latex. The acrylic latex was prepared through emulsion polymerization, and aniline was polymerized by in situ interfacial polymerization at the interface of acrylic latex/chloroform phase. Fourier transform infrared spectroscopy (FTIR), UV–Vis spectroscopy and CHNS elemental analysis revealed the existence of 6.24 wt% emeraldine salt of polyaniline (PAni) in the dried film of the nanocomposite. Scanning electron microscopy (SEM) confirmed the presence of colloidal polymer particles in the aqueous phase which was confirmed to have some advantages, including prevention of aggregation of particles, dispersibility improvement and enhancement of the PAni nanofibers aspect ratio in the acrylic polymer matrix. According to SEM results, PAni fibers with the length ranging from 12 to 67 µm and diameters between 0.078 and 1 µm, highly dispersed in the acrylic polymer matrix, were successfully synthesized. Thermal, electrical and mechanical properties of the acrylic copolymer were significantly affected by PAni incorporation. The onset degradation temperature in thermogravimetric analysis revealed that the thermal stability of the nanocomposite was improved compared to that of the pure acrylic copolymer. The nanocomposite film showed electrical conductivity of about 0.025 S/cm at room temperature, along with satisfactory mechanical properties, attractive as an antistatic material in coating applications. © 2016, Iran Polymer and Petrochemical Institute.
Rahim-abadi, M.M.,
Mahdavian, A.R.,
Village, A.,
Salehi-mobarakeh, H. Progress in Organic Coatings (03009440)88pp. 310-315
Encapsulation of inorganic nanoparticles by polymers is one of the interesting research topics that lead to the synthesis of nanocomposites. These nanocomposite materials comprise the properties of both organic polymer and inorganic nanoparticles. Here, hybrid latex particles with core-shell nanostructure were prepared via semi-batch emulsion polymerization. Copolymers of (methyl methacrylate-butyl acrylate) and (dimethylaminoethyl methacrylate-butyl acrylate-acrylic acid) were formed as the inner and outer layers, respectively on the surface of modified TiO2 nanoparticles as the core. In order to create compatibility between inorganic and polymeric phases, modification of TiO2 nanoparticles was performed with glycidyl methacrylate with an optimized procedure for the first time and then emulsion polymerization was carried out. The products of each step were fully characterized. The results of dynamic light scattering, TEM and SEM analyses proved the formation of encapsulated hybrid latex particles. DLS and SEM data revealed that the sizes of nanocomposite particles vary between 85 and 120 nm for 0-5 wt% of the modified TiO2 nanoparticles. Physico-mechanical properties of the obtained nanocomposite films were studied by DMTA. It was found that using only 3 wt% of modified TiO2 improved those properties of resulting films remarkably. © 2015 Elsevier B.V. All rights reserved.
Polymer nanocomposites are commonly defined as the combination of a polymer matrix and additives that have at least one dimension in the nanometer range. One of the most important fields which have gained an increasing interest in recent years is magnetic nanocomposites. In this review, the basics of magnetic properties of materials will be presented along with emulsion polymerization approach to magnetic latexes. © 2014 by Apple Academic Press, Inc.
Iranian Polymer Journal (English Edition) (17355265)23(1)pp. 27-35
The improvement in toughness of rigid polymers like poly(vinyl chloride) (PVC) has been of great interest for developing their applications. This could be provided by designing impact modifiers which could be blended with the polymeric matrix. Here, core-shell type impact modifier particles with different glass transition temperatures of the shell and specifically, with nanometric shell thickness were prepared through seeded emulsion polymerization. The core consisted of polybutadiene particles and the shell was made of poly(methylmethacrylate-co-butyl acrylate) that was grafted onto the surface of the seed particles. The polymerization reaction was optimized and the resulting latex particles were well characterized by several techniques such as DSC, DLS, SEM, and TEM. It was found that the core-shell particles have diameters of about 350-360 nm, including the shell with thickness of almost 20-30 nm and glass transition temperatures ranging between 70 and 120 C. The prepared particles were blended with PVC and the corresponding impact strengths of the moldings were measured by means of Izod impact test. The impact results revealed that by decreasing T g of the shell in impact modifier particles, the impact resistance of the molded sheets increased remarkably. Also the brittle-ductile transition temperatures (BDTT) of the prepared blends were studied and an increase in BDTT was found with lowering T g of the shell. © 2013 Iran Polymer and Petrochemical Institute.
