Mixture Of Polymethylmethacrylate Research Articles

Efficient high-throughput method utilizing neural network potentials to calculate interaction energies, validated by clean transfer experiment of CVD graphene with polymer mixtures

In this study, we designed a computational model involving energy decomposition using ground state energy minimized geometries resulting from a general-purpose neural network potential (ANI-1ccx). The numerical simulations show a distribution of energies, which indicate a two-fold reduction in interaction energy and polarity shift in electrostatic interaction, highlighting the computational novelty in exploring over a million metastable configurations. Experimentally, we validate our model by observing that using a mixture of two distinct polymers in the wet transfer process reduces transfer-induced doping and strain on transferred CVD graphene compared to the conventional single polymer wet transfer method, primarily due to decreased polymer contamination from the transfer process. This reduction is linked to the decreased interaction energy in the mixture of polymethyl methacrylate and angelica lactone polymer on graphene.

Expression of VEGF and BMP-2 in Osteoblast cells exposed to a combination of polymethylmethacrylate (PMMA) and hydroxyapatite (HAp).

Polymethylmethacrylate (PMMA) has been widely used, but it has several fallback properties in its interaction with bone tissue, so the addition of hydroxyapatite (HAp) material aims to improve the biocompatibility, regeneration process, and osteointegration of bone implants. The HAp material can be sourced from bovine bone and processed through Good Manufacturing Practice from Tissue Bank (HApGMP), and from limestone (CaCO3) processed by Balai Besar Keramik (HApBBK).This study was to observe the expression of vascular endothelial growth factor (VEGF) and Bone morphogenetic protein-2 (BMP2) in cultured osteoblasts exposed to PMMA-HApGMP and PMMA-HApBBK as implant candidate materials. Sample of PMMA and HAp materials with a mixture of PMMA and HApBBK in the first group and a mixture of PMMA and HApGMP in the second group. Twenty-four fetal rat calvarie osteoblast cell cultures were randomly divided into 6 groups: 7- and 14-day control group, 7 and 14 days PMMA-HApGMP group, 7 and 14 days PMMA-HApBBK group. The expression of VEGF and BMP-2 was seen by immunocytochemical examination. The one-way ANOVA with a significance value of 0.000 (p<0.05). BMP-2 and VEGF expression was increased in the 7- and 14-days groups after exposure to PMMA-HApGMP and PMMA-HApBBK. The application of PMMA-HApGMP and PMMA-HApBBK showed an increase in the expression of VEGF and BMP-2 in osteoblast cell cultures which indicates a potential increase in the accelerated angiogenesis and osteogenesis in the bone regeneration process of bone implants.

RUNX2 and ALP expression in osteoblast cells exposed by PMMA-HAp combination: An in vitro study.

To observe the expression of Runt-Related Transcription Factors 2 (RUNX2) and Alkaline Phosphatase (ALP) markers in osteoblast cell cultures exposed to Polymethylmethacrylate (PMMA) combined with hydroxyapatite (HAp) material to improve osteointegration of bone implants. Sample of PMMA and HAp materials with a mixture of PMMA with HAp made from limestone as natural source which processed through Balai Besar Keramik (HApBBK) in the first group and a mixture of PMMA with HAp made from bovine bone which processed through Good Manufacturing Practice (HApGMP) in the second group. Twenty-four fetal rat calvarie osteoblast cell cultures were randomly divided into 6 groups: 7- and 14-day control group, 7 and 14 days PMMA-HApGMP group, 7 and 14 days PMMA-HApBBK group. The expression of RUNX2 and ALP was seen by immunocytochemical examination. The one-way ANOVA with a significance value of 0.000 (p<0.05). There was an increase in RUNX2 and ALP expressions on both PMMA-HApBBK and PMMA-HApGMP groups on days 7 and 14 in osteoblast cell cultures. The PMMA-HApBBK and PMMA-HApGMP showed an increase in the RUNX2 and ALP expression in osteoblast cell cultures which indicates a potential increase of osseointegration of bone implants.

Infrared Spectroscopy of Polymers X: Polyacrylates

Acrylate polymers are derivatives of acrylic acid, but contain a plethora of different functional groups and are best discussed by themselves. In this column, we study the spectrum of an important polymer, polymethyl methacrylate (PMMA), which is otherwise known as plexiglass, and is found in windows, car parts, and paint. We then study the spectra of PMMA mixtures and copolymers in detail.

Synthesis and characterization of macroporous tin oxide coatings

Porous coatings of tin dioxide (SnO2) with a high surface area were obtained using a modified method on glass slides. The coatings were obtained with the “Doctor Blade” method and a closed drying system at room temperature. This drying system provides favorable conditions to decrease significantly cracks on the macroporous coatings. This is an alternative way to synthesize macroporous coatings using polymethylmethacrylate (PMMA) microspheres as a template. A precursor dispersion was made from the mixture of PMMA and tin tetrachloride salt dissolution at 0.5 M. The coatings synthesis parameters were optimized to obtain a uniform porous layer. The precursor dispersion and coatings were studied by thermogravimetric analysis. The coatings material surface area was 87 m2/g determined by BET, and the crystalline structure was characterized by X−ray diffraction. The structure and morphology of the coatings were determined with optical and electron microscope techniques, and the residual contaminations were studied by IR spectroscopy. The macroporous spherical diameter is around 312 ± 35 nm, and they are built by nanocrystalline size particles of 6 ± 1 nm in diameter.

Gel permeation chromatography process for highly oriented Cs3Cu2I5 nanocrystal film

The emergence of green materials has attracted considerable attention in the field of optoelectronics. Copper-based lead-free metal halide (with a near-unity quantum yield) obtained from Cs3Cu2I5 nanocrystals (NCs) can exhibit blue emission with a wavelength of 440 nm and provide outstanding stability for various applications. However, in practical applications, colloidal dispersion purity and film quality are inadequate toward a high-performance device. In this study, antisolvent-free gel permeation chromatography is used to purify Cs3Cu2I5 NCs. The purified Cs3Cu2I5 NCs exhibit a high photoluminescent quantum yield and provide a highly oriented single-crystal film. Density functional theory calculation results indicate that the iodide-rich surface in the NCs makes them highly stable. In addition, it has been demonstrated for the first time that the mixture of polymethyl methacrylate (PMMA) and Cs3Cu2I5 NCs has waterproofing capabilities. The composite film consisting of Cs3Cu2I5 NCs and PMMA can survive in water for several days. This result opens up more possibilities for the application of these green material.

Evaluation of biocompatibility, osteointegration and biomechanical properties of the new Calcemex® cement: An &lt;em&gt;in vivo&lt;/em&gt; study

The mixture of polymethylmethacrylate (PMMA) and β-tricalciumphospate (β-TCP) is the most widely used bone graft. Common features of bone cement are the biocompatibility, bioactivity, mechanical stability and ability to fuse with the host's bone tissue. However, there are still few studies that have evaluated these characteristics in vivo. Our study aims to acquire these parameters, using an animal model with functional characteristics similar to those of humans. The analyzed cement is Calcemex®, evaluated both in compact and fluid formulation. The chosen animal models were 5 pigs, treated with femoral and tibial implants of Calcemex® samples. After one year, the pigs were sacrificed and the specimens explanted for morphological, histological, ultrastructural and mechanical evaluations. For both formulations, the investigation highlighted the absence of foreign body reactions in the host, the histological integration with the surrounding tissues and the preservation of mechanical compression resistance.

Гибридный металлополимер на основе полиметилметакрилата с внедренными металлическими наночастицами как активная среда оптоакустического генератора ультразвука

A study was made of a hybrid metal-polymer material consisting of polymethyl methacrylate (PMMA) and nanoparticles distributed throughout its volume, silver, gold, copper or aluminum. The effective permittivity and absorption cross section are calculated, and the processes of temperature relaxation are modeled. It has been shown that mixtures of PMMA with silver, copper, aluminum, or gold nanoparticles can be used as an active medium in optoacoustic ultrasound generators.

A hybrid metal polymer based on polymethyl methacrylate with embedded metal nanoparticles

A study was made of a hybrid metal-polymer material consisting of polymethyl methacrylate (PMMA) and nanoparticles distributed throughout its volume, silver, gold, copper or aluminum. The effective permittivity and absorption cross section are calculated, and the processes of temperature relaxation are modeled. It has been shown that mixtures of PMMA with silver, copper, aluminum, or gold nanoparticles can be used as an active medium in optoacoustic ultrasound generators. Keywords: hybrid material, ultrasound generator, nanoparticle, polymethyl methacrylat.

Thermophysical characterization of the mixture of PMMA & acetone

The inter-molecular interactions, intra-molecular interactions, structural properties and physiochemical behaviour can be explained by knowing the thermo-physical properties of the polymer–solvent mixture. In the present research work, these properties have been studied by using an ultrasonic interferometer by measuring the sound velocity in the mixture of polymer and solvent. With the in-depth knowledge of molecular interactions, the physical properties of these ferroelectric polymers have been explained at a deeper level. In our experimental investigation the polymer, PMMA (polymethyl methacrylate) is used. The mixture is prepared by dissolving the polymer in acetone. Ultrasonic waves of frequency 5 MHz via ultrasonic interferometer is passed through the polymer–solvent mixture of different (w/v) percentage at 2 %, 4 %, 6 %, 8 % & 10 % at various temperatures 308 K, 313 K, 318 K, 323 K, 328 K, & 333 K and ultrasonic wave velocity is measured. The acoustical parameters such as ultrasonic attenuation, adiabatic compressibility, relaxation time, & acoustic impedance have been calculated using the ultrasonic wave velocity. The experimental observations are discussed in detail.

Effect of Low Nanodiamond Concentrations and Polymerization Techniques on Physical Properties and Antifungal Activities of Denture Base Resin.

Background: Denture base resin has some drawbacks. This study investigated the impact of nanodiamonds (ND) and autoclave polymerization on the surface characteristics, translucency, and Candida albicans adherence in polymethyl methacrylate (PMMA) denture base resin after thermocycling. Methods: Heat-polymerized PMMA discs (15 × 2 mm) with a total sample size n = 160 were studied. Specimens were categorized into two main groups (N = 80): conventional water-bath-polymerized PMMA (CP/PMMA) and autoclave-polymerized PMMA (AP/PMMA). Each group was subdivided according to the ND concentration into four groups (n = 20): unmodified PMMA as a control, and 0.1%, 0.25%, and 0.5% ND–PMMA. Scanning electron microscopy (SEM) was used to inspect the morphology of the ND and the ND–PMMA mixtures before heat polymerization. The specimens were exposed to thermal cycling (5000 cycles at 5 and 55 °C), then surface roughness was measured with a non-contact optical interferometric profilometer, contact angle with an automated goniometer, and translucency using a spectrophotometer. Colony-forming units (CFU) were used to determine the adherence of Candida albicans cells to the specimens. ANOVA and Tukey post hoc tests for pairwise comparison were utilized for the statistical analysis (α = 0.05). Results: Surface roughness was significantly reduced with ND addition to CP/PMMA (p ˂ 0.001), while the reduction was not statistically significant in AP/PMMA (p = 0.831). The addition of ND significantly reduced the contact angle, translucency, and Candida albicans count of CP/PMMA and AP/PMMA (p ˂ 0.001). The incorporation of ND in conjunction with autoclave polymerization of PMMA showed significant reduction in all tested properties (surface roughness, contact angle and Candida albicans adherence) except translucency (p = 0.726). Conclusions: ND addition to PMMA and autoclave polymerization improved the surface properties with respect to antifungal activities, while the translucency was adversely affected.

Dynamics of radiative-reactive Walters-b fluid due to mixed convection conveying gyrotactic microorganisms, tiny particles experience haphazard motion, thermo-migration, and Lorentz force

The significance of the dynamics of mixture of polymethyl methacrylate and pyridine at 25 C containing 30.5 g of polymer per litre with density 0.98 g per litre has led to countable published facts with the intention to come up with insightful suggestions and recommendations for the expert in biofuel, bioengineering, biomedical, and mechanical engineering applications. However, nothing is known on the increasing bioconvection Rayleigh number, velocity ratio, Lorentz force, Prandtl number, bioconvection Peclet number, bioconvection Lewis number, and microorganisms concentration Biot number. The Spectral Local Linearization Method (SLLM) and MATLAB in-built package were adopted to solve the dimensionless form of the corresponding governing equation for the dynamics of radiative-reactive Walters-B fluid due to mixed convection when tiny particles experience haphazard motion, thermo-migration, and Lorentz force are significant and analyzed. It can be concluded that the Nusselt number proportional to the heat transfer rate can be declined by rising Lorentz force. The microorganism’s flux at the wall is a decreasing property of Prandtl number and bioconvection Peclet number. Increasement in the temperature distribution of the fluid flow is a property that could be enhanced through enhancement in the Lorentz force.

Preparation of microsieves with a hierarchical structure via float-casting, using raspberry particles

This article describes the preparation of hierarchical microsieves via float-casting using raspberry particles. The raspberry particles consist of a larger spherical particle (the core) and smaller particles (satellites) that are attached on the surface of the core and were connected to the core via a surface reaction of isocyanate and amino groups. The raspberry particles were spread onto a water surface as a monolayer and a mixture of polymethylmethacrylate (PMMA) and toluene was poured over this monolayer. After evaporating the solvent, a composite membrane composed of a continuous polymer film with particles protruding out of at least one of its interfaces is obtained. The raspberry particles were etched away, and the membrane thus converted into a hierarchical microsieve comprising larger and smaller pores caused by the core and satellite particles, respectively. The most promising raspberry particles for this purpose consisted of glass beads of 75 μm diameter as core and Stöber-particles of 316 nm respectively 275 nm diameter. The resulting microsieves were suitable for filtration and permeance tests. The permeance at low Reynold numbers (low liquid flow velocity through the pores) is in accordance with established values for microsieves. The membranes were able to retain particles exceeding the pore size.

Experimental based approach for reduced-order models of porous media properties prediction

Abstract The pore diameter, type (open or closed), physical properties of Porous alumina ceramic were controlled by varying concentration in the mixture of Polymethylmethacrylate (PMMA) with alumina powder and sintering temperature. The porous alumina ceramic was synthesis by a dry pressing method using a microspheres Polymethylmethacrylate (PMMA) as a pore-forming agent. The properties of the porous alumina were predicted using an experimental approach. Afterwards, the measured data were used to develop a Reduced-order model (Kriging) to enable a fast prediction of the properties for an extended range of parameters variation and further analysis. The experimental results showed that the High porous alumina ceramics is having an open porosity of 72.3%, and a bulk density 1.2 gm/cm3 and these could be fabricated using PMMA microspheres. Kriging model results showed an acceptable prediction of the experimental-derived data with a maximum discrepancy of 0.02% for the apparent porosity.

Saline solution impedance sensor based on Poly Methyl Methacrylate and graphite: preliminary results

This paper shows a preliminary study of behaviour comparison in NaCl and KCl saline solutions of three screen printed bipolar electrodes with a coating mixture of Poly Methyl Methacrylate (PMMA) and graphite. Results indicate greater selectivity of the coating electrodes with partial ring geometry compared with concentric and spiral bipolar, cover mixture allows eliminating electrolyte electrode interface in low frequencies. The benefits of using this electrode are: optimize sample measurements; low-cost manufacturing; integration feasibility into a mobile device. Upcoming research requires including test with other ionic solutions and new doped graphite composes.

Intermolecular Interactions in Binary Mixture of Polymethylmethacrylate

Intermolecular Interactions in Binary Mixture of Polymethylmethacrylate

Effect of Polymethylmethacrylate-Hydroxyapatite Composites on Callus Formation and Compressive Strength in Goat Vertebral Body.

Introduction: Percutaneous vertebroplasty (PV) is one of the available treatments for vertebral compression fracture (VCF). Polymethylmethacrylate (PMMA) is the most common bone substitute used in the procedure, but it has several disadvantages. Bioceramic material, such as hydroxyapatite (HA), has better biological activity compared to PMMA. The aim of this study was to find an optimal biomaterial compound which offers the best mechanical and biological properties to be used in PV.Materials and Methods: This was an experimental study with goat (Capra aegagrus hircus) as an animal model. The animals’ vertebral columns were injected with PMMA-HA compound. Animal samples were divided into four groups, and each group received a different proportion of PMMA:HA compound. The mechanical and biological effects of the compound on the bone were then analysed. The mechanical effect was assessed by measuring the vertebral body’s compressive strength. Meanwhile, the biological effect was assessed by analysing the callus formation in the vertebral body.Results: The optimal callus formation and compressive strength was observed in the group receiving PMMA:HA with a 1:2 ratio.Conclusion: A mixture of PMMA and HA increases the quality of callus formation and the material’s compressive strength. The optimum ratio of PMMA:HA in the compound is 1:2.

A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation

A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO4) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO4 concentration 2mmolL−1, treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL−1. Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO4 solution is feasible, enabling the process greener.

Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties

Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

Modeling and experimental studies of methyl methacrylate polymerization in a tubular reactor

In this study, rheological examination of the mixture of a tubular reactor in which methyl methacrylate was polymerized has been studied. The n (flow behavior index) value of Power Law Model of mixture contained in the reactor has been determined within the span of 0.3492 to 0.9889 by curve fitting. Employing these numerical data for velocity profile, the reactor has been modeled. Moreover, the functions of the reactor have been compared in the three modes of plug, mixed and laminar flow. The results obtained in this research indicate that the polymethyl methacrylate mixture contained in the reactor is pseudo-plastic. Moreover, as the conversion grows, the velocity profile starts as a parabolic profile and approaches the plug mode; although it never reaches the plug. The other conclusions borne in this study indicate that when the reactor's radius is decreased, the conversion rate grows. However, as decreasing the radius would also reduce the productions rate, this procedure is not economical. Finally, in this modeling, the amount of conversion is equal to 56.47% at the end and according to its laboratory proportion which is 55.88%, it has reached the conclusion that the modeling duly undertaken is applicable and valid.