Poly Methyl Methacrylate Research Articles

Evaluation and comparison of the antimicrobial efficacy of three commercially available denture cleansing agents against different microorganisms: An in vitro study

Heat cured poly methyl methacrylate denture base acrylic resins are most commonly used material for fabrication of complete dentures. In certain situations, denture hygiene is compromised both due to the constraints of the denture material and/or non-compliance from the patients owing to lack of manual dexterity. This leads to formation of microbial biofilm on the intaglio surface of the denture and if left untreated, it can cause denture stomatitis. Denture cleansing tablets are of great help in such cases.The primary goal of this in vitro experiment was to assess and compare the effects of commercially available and common household denture cleansing tablets viz. Polident, Fittydent and Clinsodent against Staphylococcus aureus, Streptococcus mutans and Candida albicansA total of 100 heat polymerized acrylic resin samples were divided into 4 groups of 25 each to evaluate the antimicrobial effectiveness of commercially available denture cleansing agents.The results of this study showed that there was significant reduction in colony forming units in three commercially available denture cleansing agents (Clinsodent, Fittydent and Polident denture cleansing tablets) as compared to distilled water. All three commercially available denture cleansing agents used in the study were capable of reducing the colony forming units per ml of the heat cure acrylic resin denture base samples. The order of efficacy was Clinsodent tablets > Fittydent tablets > Polident tablets > Distilled water.

Application of MATLAB and SAS Viya AI models towards the elucidation of potential microplastics in the Neuse River Basin

Microplastics (MPLs) are ubiquitous particles derived from degradation from plastic refuse or directly from anthropogenic sources. These particles are present in aquatic environments with potential toxicology across the biosphere. In order to characterize their presence, the Neuse River basin was selected for sampling. However, like many MPLs, spectroscopic characterization can be sullied by weathering processes that obscure the native spectra. Therefore, to enhance MPL identification, Principal Component Analysis (PCA), K-means Clustering (KMC), MATLAB, and SAS Viya’s machine learning (ML) modules were implemented on the Neuse River basin's samples. 18 unknown samples were recorded with attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy against the controls for PCA and KMC: high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and nylon-6 (PA6). Later on, these unknowns were tested against a new set of 900 commercial control samples partitioned by 9 classes for MATLAB and SAS Viya: cellulose acetate (CA), HDPE, LDPE, PP, PS, PVC, PET, polymethyl(methacrylate) (PMMA), and PA6 using µ-FTIR (micro-FTIR) for single-particle discrepancy. Application of MATLAB’s Classification Learner and SAS Viya for Learners software helped aggregate multiple machine learning (ML) models to test for corroboration of predictions with datasets derived from Version 1 (V1), Version 2 (V2), and Version 3 (V3) feature extraction algorithms. Novel feature extractions, based on regressions of discrete data from spectral intensities, in V2 and unique probing of the relationships informing the regressions in V3 showed moderate to moderately high predictor strength, contributing to accuracy increase in V3 according to various predictor strength algorithms in MATLAB. In the test scenario of the strongest version, V3, 63.2% (+ 5.3% from V1) of the models performed very strongly (90% cutoff in accuracy), and 89.5% (+ 0% from V1) of the models performed moderately strongly (80% cutoff in accuracy). The models, coupled with the unsupervised PCA and KMC, indicated microparticle (MP) from Stockinghead Creek in Duplin County, NC; SHR-1b(2), as LDPE. However, the change in corroboration across model types was not significant, according to Kruskal-Wallis (H = 0.555, p = .7577). An ANOVA was performed to see if LDPE incidence was similar across all unknowns, indicating a similar ratio of predictions, excluding NRCP-1 (F = 31.479, p < .0001). While it is unclear if this particle is truly LDPE, the results may suggest that LDPE could be of high presence in the river basin (specifically, PE) when taking into account the predictor set across all versions. Lastly, misclassification was further elucidated for samples “CF-3” and “NRCP-1(2)” which are thought to be extensively-degraded PVC MPLs.

Flexible and Compact PVDF/PMMA-Based Gel Polymer Electrolytes for High-Performance Sodium Metal Batteries.

Sodium is gaining recognition as a promising alternative to lithium for battery applications, particularly in sodium metal batteries (SMBs), where the performance is critically influenced by the choice of electrolyte. Although conventional organic liquid electrolytes are widely used, they pose significant issues. Gel membrane (GM)-based electrolytes have demonstrated enhanced reliability and stability. Nevertheless, there remains a pressing need to improve their electrochemical and mechanical properties to fulfill the demands of next-generation batteries, which require extended lifespan, rapid charging capabilities, and excellent flexibility. To address these challenges, a compact and flexible GM is developed by gelating a cast Polyvinylidene fluoride (PVDF)/Polymethyl methacrylate (PMMA) blend film. The resulting GM possesses a suitable sodium ionic conductivity of 0.507 mS cm-1 and an impressive ion transference number of 0.47, enabling dendrite-free reversible sodium plating and stripping for up to 300 h at a current density of 0.8 mA cm-2. Furthermore, the effectiveness of sodium dendrite suppression is demonstrated in Na/GM/Na3V2(PO4)3 cells, which exhibit a high discharge capacity and excellent cycling stability. The flexible SMB retains stable voltage output and continues to function even when bent or twisted. This study introduces a novel strategy for creating gel electrolytes for high-performance flexible SMBs.

Evaluation of Microplastics Ingested by Sea Cucumber Holothuria Scabra from Pulau Jambongan, Sabah.

Microplastics (MPs) are tiny plastic pieces having a diameter of less than 5mm. They can arise from larger plastic debris that degrades over time, synthetic fibres from clothing, microbeads in personal care items and even larger plastic debris. Sea cucumbers are marine creatures vital to the ocean's ecosystem as they assist in maintaining a clean seabed and recycle nutrients. The aim of this research was to characterize the types of MPs isolated from the sea cucumber Holothuria scabra from Pulau Jambongan, Sabah. A total of 30 H. scabra were collected. Their gastrointestinal tracts were removed and digested using NaOH. The digestates were filtrated several times to extract the MPs. MPs were observed under microscope and categorized into shapes and colours. To determine the functional group of polymers, further analysis using Fourier Transform-Infrared Spectroscopy (FTIR) was performed. The samples contained a total of 7403 MPs. Majority of MPs were black colored (72.25%) and in the form of fibres (99.05%). Two types of polymers were detected: polycarbonate (PC) found in 4% of the population and polymethyl methacrylate (PMMA) present in 96%. In conclusion, the presence of MPs in the gastrointestinal tract of H. scabra suggests that the animals and their habitat have been contaminated. Further study is required to comprehend the effects of MPs on sea cucumbers and other marine organisms as well as to develop prevention strategies.

Pervaporation Membrane Development via PSf/PMMA/PDMS Polymeric Blends and ZSM-5/TiO2 Integration for Bioethanol Purification as Sustainable Green Energy

This study introduces a novel nanocomposite membrane designed for pervaporation (PV) by employing polymer blending, inorganic integration, and polymer coating techniques. ZSM-5 or TiO2 nanoparticles were synthesized and incorporated into a polysulfone (PSf) and poly(methyl methacrylate) (PMMA) matrix, followed by a coating of polydimethylsiloxane (PDMS) to enhance perm-selectivity. Comprehensive analyses confirmed the well-dispersed nature of the nanoparticles and a significant increase in hydrophilicity. The research systematically examined the effects of particle loading, PDMS coating, and temperature on the separation efficiency. The findings revealed that the PDMS-coated PSf/PMMA/ZSM-5 membrane with a 2 wt.% loading demonstrated a substantial 41% increase in permeate flux and achieved a separation factor of 61.227 ± 1.92 at 40 °C. These improvements are attributed to the establishment of water channels and the molecular sieving effect introduced by the ZSM-5 incorporation. This study suggests that the developed membrane offers promising enhancements for ethanol recovery through pervaporation, showcasing the potential of nanocomposite membranes in improving separation efficiency and selectivity.

Sucrose phononic crystal-based sensor via acoustically induced transparency

Abstract Accurate detection of sucrose concentration is vital for assessing sugar content in fruits, vegetables, and nuts. This article introduces an innovative method for sensing various sucrose concentrations using an acoustically induced transparency system integrated by a solid mechanic phononic crystal framework. The detector architecture is based on a two-dimensional phononic crystal that employs poly methyl methacrylate as its foundational material, complemented by a regularly spaced array of circular tungsten pillars. The layout features a linear waveguide linked to two coupled ring resonators, with the upper resonator housing four columns filled with varying sucrose concentrations, thereby enabling resonance frequencies that are specifically tailored to each concentration. Simulation findings demonstrate a strong correlation between the shifts in transmission peak frequency and the associated sound velocities and material densities. The sensor’s functionality is further confirmed through coupled mode theory, representative an excellent alignment with the sensor’s presentation. Particularly, the sensor achieves an impressive average quality factor of 53515, an average sensitivity of 195 Hz, a figure of merit of 4.75, a signal-to-noise ratio of 1.25, a resolution of 40 Hz, and average insertion losses of 1.48 dB. These results underscore the acoustically induced transparency system’s potential for precise sucrose concentration sensing, offering remarkable sensitivity and accuracy for agricultural applications.

Preparation of polymer hollow microsphere filled epoxy resin-based syntactic foam material and its performance analysis

To explore sound-absorbing and flame-retardant materials that meet the requirements for double-shielded and double-insulated Faraday cages, polymethyl methacrylate (PMMA) microspheres were incorporated into epoxy resin-based syntactic foam materials for testing and analysis. The addition of PMMA microspheres was found to enhance the electrical, mechanical, sound-absorbing, and flame-retardant properties of the syntactic foam, providing a potential reference for applications in high-voltage hall shielding and sound absorption. Syntactic foams with four concentrations of PMMA microspheres (0%, 0.5%, 1%, and 2%) were prepared. High-voltage breakdown testing, impedance tube testing for sound absorption coefficient, cone calorimetry for flame-retardant performance, and tensile and bending tests were conducted. Results showed that as the concentration of PMMA microspheres increased, improvements were observed in the tensile, bending, flame-retardant, and sound absorption properties of the syntactic foams, while breakdown strength decreased. These findings provide valuable insights into the application of syntactic foam materials in double-insulation, double-shielded Faraday cages.

A PDMS-Al Triboelectric Nanogenerator Using Two-Pulse Laser to Enhance Effective Contact Area and Its Application

A triboelectric nanogenerator (TENG) is a kind of energy harvester which converts mechanical energy into electrical energy with electron transfer and transport between two different materials during cycling tribology. To increase the contact area between tribo-layers and enhance the output of TENGs, many studies prepare patterned micro/nanostructured tribo-layers using semiconductor processes like lithography and etching at high cost and with long processing times. Here, we propose a new method to quickly produce high-aspect-ratio (HAR) microneedles of polydimethylsiloxane (PDMS) for TENG triboelectric layers using a two-pulse laser-ablated polymethyl methacrylate mold and casting. It has the merit of employing low-cost CO2 laser microfabrication and polymer casting in a feasible way to produce efficient tribo-electric layers. Two-pulse laser ablation is an efficient method for fabricating HAR microstructures with increasing depth at a constant width and density compared to single-pulse ablation. It enhances the depth of microneedles at a constant width and successfully casts PDMS tribo-layers with microneedles that have an aspect ratio 1.88 times higher than those produced by the traditional single-pulse process. The microneedle-PDMS (MN-PDMS) layer is combined with Al sheets to form the MN-PDMS-Al TENG. Compared with the flat PDMS-Al TENG and single-pulse PDMS-Al TENG, the two-pulse TENG enhances open-circuit voltage (Voc) by 1.63 and 1.48 times, the short-circuit current (Isc) by 1.92 and 1.47 times, and the output power by 3.69 and 2.16 times, respectively. This two-pulse ablation method promotes the output performance of TENGs, which has the potential for applications in self-powered devices and sustainable energy.

Effects of 5 Nanosilica Concentrations and Humid Environments at 6 Different pH Levels on Fracture Toughness and Moisture Absorption of Dental Polymethyl Methacrylate Resin‎ Reinforced With Silica Nanoparticles: An Explorative Experimental Scanning Electron Microscopy Study.

No study has assessed the effects of nanosilica within polymethyl methacrylate (PMMA) resin and environmental pH on resin's fracture resistance and moisture absorption. A total of 90 specimens were divided into 30 subgroups of three, as per the ASTM D5045 standard: five groups of nanosilica percentages (0%/2%/5%/7%/10%), each ‎divided into six subgroups of pH levels (pH = 5/6/7/8/9, + "dry" control). The specimens were prepared by mixing silica nanoparticles with PMMA powder in a vacuum mixer. Then, the specimens were mixed with a diluent liquid (TEGDMA) according to the manufacturer's instructions. For each of the five weight percentages, 36 samples were produced. The 18 specimens in each group were randomly divided into six subgroups of pH levels. The specimens were kept in containers of liquid at different pH levels at room temperature for 1 week. Their before- and after-storage weights were recorded to calculate moisture absorption. The fracture resistance test was performed (ASTM D5045 standard) using the three-point bending method. Scanning electron microscopy was performed. Data were analyzed. Both nanosilica extents and pH levels significantly affected the fracture toughness with a significant interaction (p < ‎‎0.00001). All post hoc comparisons of different pH levels (except pH= 5 vs. 6) were significant (p < ‎‎0.0001). All post hoc comparisons of different nanosilica concentrations were significant (p < ‎‎0.0001). Both nanosilica extents and pH levels significantly influenced the fracture toughness with a significant interaction (p < ‎‎0.00001). All post hoc comparisons of different pH levels and also between different nanosilica concentrations were significant (p < ‎‎0.0001). The correlation between moisture absorption and fracture toughness was significant (R = -0.382, p = 0.0009). Fracture toughness decreases when placed in humid and acidic environments. Also, the samples that were placed in a humid environment suffered a brittle fracture. Increasing silica nanoparticles improved fracture toughness (becoming optimal at 5 wt% nanosilica). The objective of this study was to investigate the fracture toughness of dental samples made of PMMA reinforced with various percentages of nanosilica at various pH levels. For this purpose, dental resins with various amounts of nanosilica were placed in moist media at different pH values ranging from 5 to 9 (mimicking the normal pH range of the human mouth).

AI-driven data fusion modeling for enhanced prediction of mixed-mode I/III fracture toughness

This research evaluates the use of artificial intelligence to enhance the accuracy of predictions for mixed-mode I/III fracture toughness in polymethyl methacrylate . Traditionally, assessing fracture toughness relies heavily on destructive testing methods, specifically using edge-notch disc bend specimens subjected to three-point bending tests. These established methods are not only expensive and time-consuming but also frequently limited by the availability of data. To address these challenges, this study introduces a data fusion source modeling approach. This approach integrates primary fracture toughness test data with secondary predictive data derived from the maximum tangential stress criterion and the local strain energy density criterion. By employing adaptive boosting and general regression neural network algorithms, the models developed in this research demonstrate a marked improvement in predictive performance compared to traditional primary source models. Additionally, a feature importance analysis using Shapley Additive exPlanations values reveals that the mode mixity parameter, specimen thickness, and radius are critical factors influencing fracture toughness. The study highlights that while mode mixity emerges as the most significant factor, a reduction in specimen thickness generally leads to decreased fracture toughness, whereas an increase in radius has a more complex, often negative, effect. The results of this study indicate that AI-powered models using data fusion can overcome limitations related to data scarcity, enabling more accurate predictions in fracture mechanics. Furthermore, this approach provides a pathway for utilizing AI in other engineering domains where data sets are limited.

Quasi-solid-state monolithic DSSCs with optimized spacer layers and composite electrolytes for better efficiency and stability

In this study, high-performance quasi-solid-state monolithic dye-sensitized solar cells (QS-M-DSSCs) were designed using an optimized spacer layer architecture to enhance electrolyte transport and improve cell performance. Spacer layers, made from a combination of zirconium oxide (ZrO2) and titanium dioxide (TiO2), were precisely tuned to reduce mass-transport limitations. A 5.2 μm thick ZrO2/TiO2 layer provided good light reflectance and incident photon-to-current conversion efficiency compared to double layers of either material alone. Electrochemical impedance spectroscopy analysis of the m-DSSCs revealed that this architecture (photoelectrode TiO2 layer/ZrO2/TiO2 spacer layer/counter electrode catalyst layer) significantly increased recombination resistance, leading to an improvement in open-circuit voltage. As a result, acetonitrile iodide liquid-DSSCs using N719 dye achieved a high power conversion efficiency (PCE) of 8.45 %, surpassing cells with alternative spacer designs. For fully printable QS-M-DSSCs, printable gel electrolytes (PGEs) composed of polyethylene oxide and polymethyl methacrylate in 3-methoxypropionitrile (MPN) were employed. A 5 wt% PEO/PMMA composition demonstrated fast and efficient penetration of the PGEs through spacer layers. Moreover, incorporation of 4 wt% TiO2 nanoparticles into PGEs further enhanced their electrochemical properties, achieving a PCE (7.31 %) higher than cells with liquid electrolytes (6.72 %). QS-M-DSSCs demonstrated greater stability than liquid-state DSSCs.

The design of manufacturing process of mold for producing polymeric dissolving microneedles

Introduction. Polymeric dissolving microneedles are promising way for drug delivery especially for vaccine delivery. It is an important task to create a scalable way of manufacture of dissolving polymeric microneedles. First step in this process is to create an easy and cheap way of producing negative master-molds for microneedles. Objective. To develop the laser production technology of negative master-mold for dissolving polymeric microneedles. Material and methods. Possibility of using different polymer plates (polydimethylsiloxane, polycarbonate, polystyrene, polypropylene, polymethyl methacrylate and polyethylene terephthalate) for producing negative microneedle molds and material’s surface free energy were examined. The modes of laser ablation of polymer and ways of its control were investigated. Pullulan dissolving microneedles were produced by using designed molds and examined by optical microscopy. Results. Polyethylene terephthalate was chosen as the optimal polymer for producing negative microneedle mold because it leads to producing symmetrical microneedles with desired geometry. Also the 2-step laser technology for the fabrication of polymeric microneedle molds and methods of mold’s quality control during manufacture was designed in this study. The technological scheme of polyethylene terephthalate microneedle mold’s manufacture was proposed in results of this study. The variety of manufacturing defects of polyethylene terephthalate microneedle mold and it’s causes were summarized. Conclusion. The designed laser technology of producing negative microneedle molds in combination with right mold’s material (polyethylene terephthalate) can guarantee robust producing of dissolving polymeric microneedles and gives a possibility to scale it up.

Keratoprosthesis of Brazil (KoBra): Preliminary Results of the First 2 Human Cases

Purpose: We evaluated the clinical performance of a novel keratoprosthesis (KPro) named KoBra (Keratoprosthesis of Brazil) in patients with corneal blindness. Methods: Two-piece KPro was three-dimensionally (3D) printed using titanium alloy powder (Ti-6Al-4V) and polymethyl methacrylate (PMMA). The KPros were implanted unilaterally in 2 patients who had corneal disease that was not amenable to standard corneal transplantation. An autologous full-thickness corneal graft was used as the KPro carrier. Patients were examined for at least 16 months to evaluate retention and postoperative complications. Biomicroscopy and anterior segment optical coherence tomography (AS-OCT) were performed throughout the experiment to evaluate the relationship between the KPro and the carrier graft. Results: No intraoperative complications occurred during the surgeries, and the immediate postoperative period was uneventful. The implanted KoBra integrated well into all operated eyes, and clear optics without prothesis extrusion were maintained. The mean duration of the postoperative follow-up was 17 months (range 16–18 months). AS-OCT demonstrated the correct relationship of the device and carrier at the final follow-up in all cases. Conclusions: The first short-term clinical analysis demonstrated good outcomes associated with this new technology in 2 patients who were not amenable to standard corneal transplantation. Longer follow-up and additional implantations are necessary to better assess the safety and efficacy of this device.

Revolutionizing polymethyl methacrylate toughness: Achieving 190% improvement with nanocellulose reinforcement while maintaining optical clarity

Polymethyl methacrylate (PMMA) is widely used in applications requiring high transparency and durability, such as optical lenses and protective coatings. However, its inherent brittleness limits its application in high-impact environments. This study investigates the incorporation of cellulose nanocrystals (CNCs) into PMMA to significantly enhance its toughness without compromising its optical clarity. By reinforcing PMMA with CNCs, the nanocomposites exhibited a remarkable 190% increase in toughness while maintaining 90% optical transparency. The innovation lies in achieving a balance between toughness and transparency through controlled CNC dispersion within the PMMA matrix, which minimizes excessive bonding that could lead to brittleness. Proper CNC dispersion was achieved through in-situ polymerization, allowing the nanocrystals to interact with the polymer matrix through van der Waals forces rather than covalent bonds. This approach reduces stress concentration and mitigates the formation of defects in the polymer matrix, ultimately leading to a tougher, more flexible material. In addition to enhancing mechanical properties, this study underscores the importance of controlling CNC content to preserve the intrinsic optical transparency of PMMA. These findings open new possibilities for CNC-reinforced PMMA in advanced applications that demand high mechanical performance coupled with excellent optical properties, extending its use in fields such as medical devices, protective coatings, and transparent structural materials.

Revivable self-assembled supramolecular biomass fibrous framework for efficient microplastic removal.

Microplastic remediation in aquatic bodies is essential for the entire ecosystem, but is challenging to achieve with a universal and efficient strategy. Here, we developed a sustainable and environmentally adaptable adsorbent through supramolecular self-assembly of chitin and cellulose. This biomass fibrous framework (Ct-Cel) showcases an excellent adsorption performance for polystyrene, polymethyl methacrylate, polypropylene, and polyethylene terephthalate. The affinity for diverse microplastics is attributed to the transformation of multiple intermolecular interactions between different microplastics and Ct-Cel. Meanwhile, the strong resistance of Ct-Cel to multiple pollutants in water enables an enhanced adsorption when coexisting with microorganisms and Pb2+. Moreover, Ct-Cel can remove 98.0 to 99.9% of microplastics in four types of real water and maintains a high removal efficiency of up to 95.1 to 98.1% after five adsorption cycles. This work may open up prospects for functional biomass materials for cost-efficient remediation of microplastics in complex aquatic environments.

Mechanical, permeability, and optical properties of concrete integrating light-transmitting materials with high contents and large diameters

ABSTRACT The present study focuses on developing LTC panels with high light transmission efficiency by integrating optical fibers or Polymethyl Methacrylate (PMMA) rods at volumes of 10–30% into the concrete. This aims to enhance the percentage of light intensity transmitted through the LTC to approximately 30% from the light source, a significant improvement compared to most previous studies where it was below 10%. Various configurations of these materials, differing in diameter and volume, were tested for their effects on mechanical strength, permeability, and optical properties. Unlike most previous studies using optical fibers smaller than 2.0 mm, the findings indicate that using optical fibers or PMMA rods with larger diameters improves the feasibility of casting LTC panels with ultra-high light transmission capacity and compressive strength above 40 MPa. The mechanical strength of LTC samples can be predicted based on the effective cross-section, excluding the area occupied by light-transmitting materials. The study also reveals that larger PMMA rods increase permeability due to weaker bonds with the surrounding concrete. Additionally, LTC panels can transmit colors and images without altering the original light source color, highlighting LTC’s potential for creative applications, such as smart traffic signal displays on pavements or unique architectural designs.

Antibiotic Release and Mechanical Performance of Polymethylmethacrylate (PMMA) Bone Cement: Findings from In-vitro Studies

Using Polymethylmethacrylate (PMMA) bone cement is widespread in orthopedic surgeries for implant fixation and as a carrier for antibiotic delivery to prevent and treat infections. This review comprehensively evaluates in-vitro studies investigating the antibiotic elution profiles and mechanical properties of PMMA bone cement. We explore the kinetics of antibiotic release, factors influencing elution efficiency and the impact of various antibiotics on the mechanical properties of PMMA composites. At the same time, we examine how the inclusion of antibiotics affects the mechanical integrity of PMMA, including parameters such as compressive strength, tensile strength and fatigue resistance. Through a detailed analysis of these studies, this review aims to provide insights into optimizing PMMA bone cement formulations for enhanced therapeutic efficacy and structural performance. Using Polymethylmethacrylate (PMMA) bone cement is widespread in orthopedic surgeries for implant fixation and as a carrier for antibiotic delivery to prevent and treat infections. This review comprehensively evaluates in-vitro studies investigating the antibiotic elution profiles and mechanical properties of PMMA bone cement. We explore the kinetics of antibiotic release, factors influencing elution efficiency and the impact of various antibiotics on the mechanical properties of PMMA composites. At the same time, we examine how the inclusion of antibiotics affects the mechanical integrity of PMMA, including parameters such as compressive strength, tensile strength and fatigue resistance. Through a detailed analysis of these studies, this review aims to provide insights into optimizing PMMA bone cement formulations for enhanced therapeutic efficacy and structural performance.

Marangoni-Induced Honeycomb Structures in Spin-Coated Polymer Nanocomposite Films.

This study investigates Marangoni effect-induced structural changes in spin-coated polymer nanocomposite (PNC) films composed of poly(methyl methacrylate)-grafted silica nanoparticles (NPs) and poly(styrene-ran-acrylonitrile). Films cast from methyl isobutyl ketone (MIBK) solvent exhibit distinct hexagonal honeycomb cells with thickness gradients driven by surface tension variations. Atomic force microscopy reveals protruded ridges and junctions at cell intersections, where NP concentration is the highest. Upon annealing at 155 °C, NPs segregate to the surface due to their lower surface energy, and the initially protruding features flatten and eventually form depressed channels while maintaining higher NP density than surrounding areas. Time-of-flight secondary ion mass spectrometry corroborated these findings, highlighting enhanced surface segregation of NPs in MIBK films. These defects can be eliminated using methyl isoamyl ketone (MIAK) as a solvent that produces homogeneous films of uniform thickness. This study highlights the impact of the Marangoni effect on the microstructure and surface properties of PNC films, providing insights for enhancing film quality and performance.

Stepwise Construction of Supramolecular A2B4-Type Miktoarm Star Copolymers with a Cobalt Phthalocyanine Core.

Supramolecular interactions between polymers play a crucial role in the construction of three-dimensional polymer structures with unique physical and chemical properties. In this study, we have fabricated a novel supramolecular miktoarm star copolymer (μ-star) with a cobalt(II) phthalocyanine (CoPc) core using metal-ligand coordination. Axial coordination of the terminal pyridyl group of poly(methyl methacrylate) with the CoPc core of four-armed star-shaped polystyrene provided AB4- and A2B4-type μ-stars through stepwise complexation. The spin-coated polymer films from mixed solutions of CoPcPS4 and pyPMMA in 1 : 1 or 1 : 2 mass ratios exhibited phase-separated nanodomains with smooth surfaces. Supramolecular interactions in polymer systems provide a unique topology to polymers and affect their bulk morphology.

Evaluating the Flexural Strength and Charpy Impact Strength Of CAD/CAM And Compressed Molded PMMA Dentures: An In Vitro Study

PMMA (Polymethyl methacrylate) is a wide range of polymers are commonly used for various applications in prosthodontics. And the embedding of tooth specimens for research purposes. The unique properties of PMMA, such as its low density, aesthetics, cost-effectiveness, ease of manipulation, and tailorable physical and mechanical properties, make it a suitable and popular biomaterial for these dental applications. These complete dentures can be manufactured using two techniques: (i) conventional compression molding (CCM) technique and (ii) CAD/CAM technology. The objective of this study was to evaluate the mechanical properties of CAD/CAM PMMA denture compared to compressed molded PMMA, manufactured using the CCM technique and CAD/CAM technology. The study consisted of twenty samples, divided into two groups based on their manufacturing technique (conventional and CAD/CAM), with five samples assigned to each test. The mechanical properties of the samples were tested using flexural strength, and Charpy impact strength tests after immersing the samples in artificial saliva at 37°C for one week. The results showed that using different manufacturing techniques for PMMA CDs leads to differences in measured characteristics that affect their suitability as the only available treatment for edentulous patients. However, a statistical analysis using SSPS tools showed that the differences are not significant between the CCM technique and CAD/CAM technology. Despite the lack of statistical significance, The PMMA CDs manufactured using the CAD/CAM technology route are recommended due to their better mechanical resistance properties.