Single-step Process Research Articles

Kinetic Analysis of the Curing Process of Biobased Epoxy Resin from Epoxidized Linseed Oil by Dynamic Differential Scanning Calorimetry.

The curing process of epoxy resin based on epoxidized linseed oil (ELO) is studied using dynamic differential scanning calorimetry (DSC) in order to determine the kinetic triplet (Ea, and A) at different heating rates. The apparent activation energy, Ea, has been calculated by several differential and integral isoconversional methods, namely Kissinger, Friedman, Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS) and Starink. All methods provide similar values of Ea (between 66 and 69 kJ/mol), and this shows independence versus the heating rate used. The epoxy resins crosslinking is characterized by a multi-step process. However, for the sake of the simplicity and to facilitate the understanding of the influence of the oxirane location on the curing kinetic, this can be assimilated to a single-step process. The reaction model has a high proportion of autocatalytic process, fulfilling that αM is between 0 and αp and αM < . Using as reference the model proposed by Šesták–Berggren, by obtaining two parameters (n and m) it is possible to obtain, on the one hand, the kinetic parameters and, on the other hand, a graphical comparison of the degree of conversion, α, versus temperature (T) at different heating rates with the average n and m values of this model. The good accuracy of the proposed model with regard to the actual values obtained by DSC gives consistency to the obtained parameters, thus suggesting the crosslinking of the ELO-based epoxy has apparent activation energies similar to other petroleum-derived epoxy resins.

Fabrication of Ca and P containing niobium oxide ceramic coatings on niobium by PEO coupled EPD process

Abstract Surface modification of niobium (Nb) to develop Ca and P containing niobium oxide (Nb2O5) ceramic coatings by plasma electrolytic oxidation (PEO) coupled with electrophoretic deposition (EPD) in a single step process is reported in the present study. Four coatings were obtained in silicate and phosphate electrolytes with and without the addition of hydroxyapatite (HA) nanoparticles. The phase composition, surface and cross-sectional morphology of the coatings were analysed. The corrosion resistance of the coated samples and niobium substrate was analysed using potentiodynamic polarisation (PDP) method in simulated body fluid (SBF) solution. The cell-viability and the live and dead cell morphology on the substrate and the coated samples were evaluated using L-929 cells. The adherence and growth of the L-929 cells were estimated by the direct contact assay. The surface modification by the PEO process enhanced the corrosion resistance of niobium in a fluid body environment. Among the coated samples, the PEO-EPD samples obtained in silicate electrolyte exhibited better corrosion resistance (6.02 × 10−7 mA/cm2), optimal surface properties, lower contact angle (47°), higher surface energy (50 mJ/m2), good adhesion strength (Lc = 18.1 N) and better cell viability.

Antibacterial Titanium Implants Biofunctionalized by Plasma Electrolytic Oxidation with Silver, Zinc, and Copper: A Systematic Review.

Patients receiving orthopedic implants are at risk of implant-associated infections (IAI). A growing number of antibiotic-resistant bacteria threaten to hamper the treatment of IAI. The focus has, therefore, shifted towards the development of implants with intrinsic antibacterial activity to prevent the occurrence of infection. The use of Ag, Cu, and Zn has gained momentum as these elements display strong antibacterial behavior and target a wide spectrum of bacteria. In order to incorporate these elements into the surface of titanium-based bone implants, plasma electrolytic oxidation (PEO) has been widely investigated as a single-step process that can biofunctionalize these (highly porous) implant surfaces. Here, we present a systematic review of the studies published between 2009 until 2020 on the biomaterial properties, antibacterial behavior, and biocompatibility of titanium implants biofunctionalized by PEO using Ag, Cu, and Zn. We observed that 100% of surfaces bearing Ag (Ag-surfaces), 93% of surfaces bearing Cu (Cu-surfaces), 73% of surfaces bearing Zn (Zn-surfaces), and 100% of surfaces combining Ag, Cu, and Zn resulted in a significant (i.e., >50%) reduction of bacterial load, while 13% of Ag-surfaces, 10% of Cu-surfaces, and none of Zn or combined Ag, Cu, and Zn surfaces reported cytotoxicity against osteoblasts, stem cells, and immune cells. A majority of the studies investigated the antibacterial activity against S. aureus. Important areas for future research include the biofunctionalization of additively manufactured porous implants and surfaces combining Ag, Cu, and Zn. Furthermore, the antibacterial activity of such implants should be determined in assays focused on prevention, rather than the treatment of IAIs. These implants should be tested using appropriate in vivo bone infection models capable of assessing whether titanium implants biofunctionalized by PEO with Ag, Cu, and Zn can contribute to protect patients against IAI.

GREEN SYNTHESIS OF SILVER, COPPER AND ZINC NANOPARTICLES USING TABERNAEMONTANA DIVARICATA AND ITS APPLICATION.

Nanoparticles are particles of any shape with size ranging from 10 to 100 nm. Synthesis of metal nanoparticle is a single step process, which is inexpensive and eco-friendly method. Metals such as silver, zinc and copper can be used for the production of nanoparticles. Tabernaemontana divericata have been reported to exhibit antimicrobial, antioxidant, antitumor and analgesic effect. It's used for wound healing and treatment of various diseases like skin diseases, aches, ascaris, scabies eye diseases and pain. Nanoparticles of silver, zinc and copper were biosynthesised from the stem extract of Tabarnaemontana divaricata. Characterization studies were carried out using UV spectrophotometer, FTIR &amp; SEM analysis. The nanoparticle were tested for it potential antibacterial activities. Among the three, AgNPs nanoparticle exhibited more antimicrobial activity than the CuNPs, and ZnNPs. The biomolecules in T. divericata stem extract with the potential to reduce and cap the bio reduced AgNPs were assessed with FTIR spectral measurements.

Laser-Induced Graphene Printed Wearable Flexible Antenna-Based Strain Sensor for Wireless Human Motion Monitoring

Leveraging laser-induced graphene (LIG) in various flexible polymer electronics applications is becoming tremendously popular. LIG is porous multilayer graphene generated by a single-step process using infrared CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> laser onto the carbon-based polymers. In this article, a direct LIG printed microstrip patch antenna operating at the 5.8-GHz unlicensed band is presented. Based on simulations, the proposed design exhibited the desired unidirectional radiation characteristics with a measured gain of 1.82 dBi at the resonant frequency. The LIG-based rectangular patch was printed using the CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> laser by selective reduction of polyimide (PI) sheet. The chemical properties of LIG were examined using various structural and morphological characterization techniques, which confirmed the formation of multilayer graphene. The sensitivity of the patch antenna was analyzed for measuring strain and its effect on LIG. By harnessing LIG on flexible material such as PI sheet, the antenna exhibited a threshold increase in sensitivity. The proposed sensor shows a sensitivity of 14.08 and 11.34 for compressive and tensile strain, respectively. Inspired by the significant sensitivity, the fabricated device has been examined for human motion monitoring by attaching it to the human hand for practical usage in real-time applications. The proposed antenna-based sensor reduces the number of components by eliminating external wiring and onboard battery. Moreover, it serves as both the sensing and wireless data transmitting element. Overall, this work demonstrates designing a compact, easy-to-fabricate, sensitive, and flexible antenna-based Internet of Things (IoT) sensor for motion detection, structural health monitoring, and industrial strain sensing applications.

Tuning photo-response and electronic behavior of graphene quantum dots synthesized via ion irradiation

The tuning of the photoresponse and electronic structure for ion induced graphene quantum dots (I-GQDs), through variations in the ion irradiation processing of monolayer graphene, is demonstrated. Synthesis of nano-dimensional quantum dots (3–9 nm) was observed for graphene after irradiation in the ion energy range of 100–250 eV. Remarkably, the photo-response from these GQDs can be manipulated and significantly enhanced simply with the change of ion energy. Changes to the photo-response are reflected in the appearance of an optical mode near 560 nm, and the enhancement of UV-regime absorbance by nearly 70%. The results display a method that can be useful in designing graphene quantum dot based photodetectors, in a single step process with ion irradiation, without incorporation of any metal-nanoparticles or hybrid-metal platforms. Changes in the UV absorbance are of immense significance having many potential applications in UV based detectors.

Post processing of additively manufactured parts using electrochemical jet machining

Additive manufacturing is an increasingly important counterpart to subtractive and constant volume manufacturing methods, however metal powder bed fusion methods often suffer from poor surface quality dominated by adhered unfused powder at the near-surface. Finishing steps are often required before part use in many applications, for example in aerospace components or biomedical implants, where ‘better than cast’ surfaces are sought. Here, we introduce electrochemical jet machining as a single-step process to i) selectively finish additively manufactured parts created by powder bed fusion, and ii) to subsequently micro-pattern these with the intention of increasing part functionality. Roughness of Ti-6Al-4V parts is shown to be reduced from an average Sq of 18.6 µm (as-built), to 2.4 µm upon rapid finishing, and the mechanisms of material removal are explored. Furthermore, repeating micro-dot patterns have been added to demonstrate the potential of the technique to allow tolerance superposition of additively manufactured parts.

Synthesis of yellow and red ochre: a preliminary multi-analytical, micro-invasive investigation on recipes and recognition criteria

This research aims to underline distinctive features to detect synthetic ochres on paintings, being the use of synthetic red widespread and well documented since Prehistory, while synthetic Mars yellow has been commercialized since the eighteenth century. Mars yellow was synthesized from Fe(NO3 )3 and KOH reaction, according to ancient recipes. Hematite was synthesized by heating Mars yellow and other natural yellow ochres, simulating a soft, less sophisticated, and a hard, more modern, heating. The natural products were characterized by X-ray diffraction. Micro-Fourier transform infrared spectroscopy (μ-FTIR) and scanning electron microscopy (SEM) were used, respectively, for a compositional and morphological comparison between natural and synthetic pigments. The synthetic pathway was also reproduced and followed through differential thermal analysis (DTA and TG).XRD remarked the different origin of precursory samples. SEM showed typical morphological features of Mars yellow that are partially retained even after heating, leading to the recognition of both Mars pigments—red and yellow. DTA and TG highlighted that the synthetic process sensibly differs from Mars yellow to natural ochres. Mars yellow showed a double-peak dehydration with minima at 278 and 304 °C, while a single-step process was recorded for natural ochres. Distinctive features of Mars products were for the first time characterized thanks to this combined methodology. Finally, μ-FTIR proved to be very effective to discriminate the soft heating from the hard one. In particular, hydroxyl and FeO6 bands in the fingerprint region were the most useful for this task.

One-Step Transformation from Rofecoxib to a COX-2 NIR Probe for Human Cancer Tissue/Organoid Targeted Bioimaging.

COX-2 fluorescent probes are promising tools for cancer diagnosis. Such probes have been conventionally designed by conjugating a fluorophore to COX-2 inhibitors through lengthy synthetic processes. Herein, a type of fluorescent probe for COX-2 imaging has been developed using a single-step process from rofecoxib. In total, six rofecoxib analogues were designed using this unique strategy. Several analogues retained comparative COX-2 targeting activity of rofecoxib and also exhibited attractive fluorescent properties, which were investigated using a combination of experimental and theoretical approaches. The most potent analogue, 2a1, displayed strong fluorescent imaging of COX-2 in HeLa cells overexpressing COX-2 compared to Raw 264.7 cells and celecoxib-treated HeLa cells that expressed low levels of COX-2. Notably, our studies indicate that 2a1 can differentiate human cancer tissue from adjacent tissue with much brighter fluorescence either in histological section or cultured 3D organoids. These results illustrate the potential of 2a1 as a COX-2 near infrared fluorescent probe for human cancer imaging in clinical settings.

Teams: autonome Systeme mit Entwicklungskraft für Personal und Organisation

In this contribution we elaborate on specific team development processes of consulting services. The main focus lies on agile dynamics with the ability to create meaning, opening a pathway to development or enhancing it even further: within the team, its members and the organisation as a whole. We will present an analysis of single process steps with emphasis on their role as well as emerging possibilities.

Impact of On-Farm Interventions against CTX-Resistant Escherichia coli on the Contamination of Carcasses before and during an Experimental Slaughter.

Cefotaxime (CTX)-resistant Enterobacteriaceae are still an ongoing challenge in human and veterinary health. High prevalence of these resistant bacteria is detected in broiler chickens and the prevention of their dissemination along the production pyramid is of major concern. The impact of certain on-farm interventions on the external bacterial contamination of broiler chickens, as well as their influence on single processing steps and (cross-) contamination, have not yet been evaluated. Therefore, we investigated breast skin swab samples of broiler chickens before and during slaughter at an experimental slaughter facility. Broiler chickens were previously challenged with CTX-resistant Escherichia coli strains in a seeder-bird model and subjected to none (control group (CG)) or four different on-farm interventions: drinking water supplementation based on organic acids (DW), slow growing breed Rowan × Ranger (RR), reduced stocking density (25 kg/sqm) and competitive exclusion with Enterobacteriales strain IHIT36098(CE). Chickens of RR, 25 kg/sqm, and CE showed significant reductions of the external contamination compared to CG. The evaluation of a visual scoring system indicated that wet and dirty broiler chickens are more likely a vehicle for the dissemination of CTX-resistant and total Enterobacteriaceae into the slaughterhouses and contribute to higher rates of (cross-) contamination during processing.

Statistical Tolerance Analysis of 3D-Printed Non-Assembly Mechanisms in Motion Using Empirical Predictive Models

Fused Deposition Modelling (FDM) enables the fabrication of entire non-assembly mechanisms within a single process step, making previously required assembly steps dispensable. Besides the advantages of FDM, the manufacturing of these mechanisms implies some shortcomings such as comparatively large joint clearances and geometric deviations depending on machine-specific process parameters. The current state-of-the-art concerning statistical tolerance analysis lacks in providing suitable methods for the consideration of these shortcomings, especially for 3D-printed mechanisms. Therefore, this contribution presents a novel methodology for ensuring the functionality of fully functional non-assembly mechanisms in motion by means of a statistical tolerance analysis considering geometric deviations and joint clearance. The process parameters and hence the geometric deviations are considered in terms of empirical predictive models using machine learning (ML) algorithms, which are implemented in the tolerance analysis for an early estimation of tolerances and resulting joint clearances. Missing information concerning the motion behaviour of the clearance affected joints are derived by a multi-body-simulation (MBS). The exemplarily application of the methodology to a planar 8-bar mechanism shows its applicability and benefits. The presented methodology allows evaluation of the design and the chosen process parameters of 3D-printed non-assembly mechanisms through a process-oriented tolerance analysis to fully exploit the potential of Additive Manufacturing (AM) in this field along with its ambition: ‘Print first time right’.

Novel Self-Directing Single-Polymer Jet Developing Layered-Like 3D Buckled Microfibrous Scaffolds for Tissue Engineering Applications.

Electrospinning is a promising technique for the fabrication of bioscaffolds in tissue engineering applications. Pertaining issues of multiple polymer jets and bending instabilities result in random paths which lend poor controllability over scaffolds morphology for affecting the porosity and mechanical stability. The present study alleviates these challenges by demonstrating a novel self-directing single jet taking a specifically patterned path to deposit fibers into circular and uniform scaffolds without tuning any externally controlled parameters. High-speed camera observation revealed that the charge retention and dissipation on the collected fibers caused rapid autojet switching between the two jetting modes, namely, a microcantilever-like armed jet motion and a whipping motion, which sequentially expand the area and thickness of the scaffolds, respectively, in a layered-like fashion. The physical properties showed that the self-switching dual-jet modes generated multilayered microfibrous scaffolds (MFSs) with dual morphologies and varied fiber packing density, thereby establishing the gradient porosity and mechanical strength (through buckled fibers) in the scaffolds. In vitro studies showed that as-spun scaffolds are cell-permeable hierarchical 3D microporous structures enabling lateral cell seeding into multiple layers. The cell proliferation on days 6 and 9 increased 21% and 38% correspondingly on MFSs than on nanofibrous scaffolds (NFSs) done by conventional multijets electrospinning. Remarkably, this novel and single-step process is highly reproducible and tunable for developing fibrous scaffolds for tissue engineering applications.

A single-step process to leach out rare earth elements from coal ash using organic carboxylic acids

The ever increasing applications of rare earth elements and their limited primary resources has compelled researchers worldwide to find alternate methods of efficient leaching from various secondary resources, in particular from end of life products. The present research work describes such a process to extract rare earth elements from coal ash using low molecular weight carboxylic acids. Different carboxylic acids, i.e. monocarboxylic (lactic acid), dicarboxylic (malonic acid, succinic acid, tartaric acid) and tricarboxylic acid (citric acid) were used to successfully leach out significant proportion of rare earth elements (up to 62%) from coal ash at the natural pH of the carboxylic acid solutions (pH 1.6–2.3). The carboxylic acid concentration, leaching duration, temperature, and pulp density were optimized for the leaching process. Best leaching efficiency (65% for LREE, 19% for HREE & 62% for total REE) was achieved using 5% tartaric acid solution having natural solution pH 1.8 at 90 °C with a leaching duration of 60 min. The leaching efficiency of the different carboxylic acids were in the order of tartaric acid>lactic acid>citric acid>malonic acid>succinic acid. The leaching kinetics of individual rare earth elements was found to be different from each other owing to their different complex formation ability with carboxylic acids. Appreciable selectivity was observed for leaching of rare earth elements over transition metal and main group elements. XRD and electron probe micro analyzer (EPMA) studies revealed that unlike mineral acids, carboxylic acids leached out rare earth elements without damaging the minerology of coal ash, thus providing the opportunity to utilize the treated coal ash for other applications like in cement and bricks industries. Thus, the novelty of the present work lies in efficient and selective leaching of lanthanides from coal ash using only organic acids, which are considered much milder and greener options compared to mineral acids.

Coaxial semi-solid extrusion and ionotropic alginate gelation: A successful duo for personalized floating formulations via 3D printing

With the aim to fulfill the patient-centered approach of precision medicine, in this research, innovative floating drug delivery systems have been developed through the use of alginate matrix and fully characterized. Particularly, to exploit the ionotropic gelation of alginate, a customized coaxial extruder for Semi-solid Extrusion 3D printing, has been used for the simultaneous dispensing of ink gel (sodium alginate 6% w/v) and crosslinking gel (hydroxyethyl cellulose 3 %w/v, calcium chloride 0.1M and Tween 85 0.1% v/v). The latter also loaded with Propranolol Hydrochloride 12.5%w/v. A novel single-step process gelation for the extemporaneous gelation of loaded oral systems has been therefore developed.These technologically advanced formulations showed high printing reproducibility in manufacturing different models (mass of a single layer 535.41 ± 40.00 mg with an average drug loading efficiency of 85% w/w) and similar release behavior, paving the way for their customization in terms of drug dosages via this pioneering process.

Composite magnetic and non-magnetic oxide nanostructures fabricated by a laser-based technique

The paper presents experimental results on fabricating composite nanostructures consisting of magnetic and non-magnetic metal oxide nanoparticles. The samples were produced by a single-step process of pulsed laser deposition carried out in air at atmospheric pressure in the presence of a magnetic field. Part of the depositions was performed by ablation of two metals simultaneously – Fe and Zn, and Fe and Ti. Another part of the experiments included simultaneous depositions from metal oxide targets – Fe2O3 and ZnO, and Fe2O3 and TiO2 as well as from metal and metal oxide (Fe-TiO2) targets. The depositions were performed in a magnetic field in order to control the magnetic nanoparticles produced in the plasma plume and thus, the morphology of the composite nanostructures. The structure and morphology of the structures obtained were studied as related to the samples’ composition. It was found that the difference in the ablation threshold of the initial ablated materials determines the use of a specific methodology for composite fabrication. The nanostructures prepared could be used in the design of novel magneto-optic and sensor devices.

Friction stir extrusion of ultra-thin wall biodegradable magnesium alloy tubes — Microstructure and corrosion response

Magnesium alloys are increasingly being considered for structural systems across different industrial sectors, including precision components of biomedical devices owing to their high specific strength and stiffness, biodegradability. For example, tubular devices such as coronary stents manufacture require defect-free, high-quality tubes with thin walls (100 μm – 1 mm) as a precursor. Here, we have produced fully consolidated, structurally sound ultra-thin walled (∼ 400 μm) AZ31 Mg alloy tubes by friction stir back extrusion (FSE) — a relatively new severe deformation process used typically to manufacture thick metallic tubes and rods. The tube cross-sectional microstructure was layered and consisted of a severely deformed stir zone with refined grains near the inner edge, a back-extruded zone with small grains near the outer edge, and a thermomechanically affected zone (TMAZ) with coarse grains develop within the central region. On the other hand, the inner tube surface microstructure had an average grain size of 4.1 ± 1.9 μm and a strong basal texture. In comparison, the outer tube surface microstructure was coarse, with an average grain size of 13.3 ± 6.4 μm with no preferred orientation. The microhardness variation along the tube wall thickness indicated the operation of multiple deformation paths during FSE. Upon exposure to Hank’s balanced salt solution at 37 °C, microgalvanic coupling resulting from the gradient through-the-thickness grain size and texture differences between the tube inner and outer surfaces, and residual strain arising from the FSE process, promoted a localized attack that preferentially initiated on the outer tube surface and progressed inwards. Static recovery induced by a short duration heat treatment at low temperature did not alter the microstructure but promoted a more general corrosion attack with a significantly reduced corrosion rate. Our results establish that FSE is a viable single-step process to manufacture ultra-thin Mg alloy tubes suitable for degradable precision tubular applications.

Fast Thermoresponsive Poly(oligoethylene glycol methacrylate) (POEGMA)-Based Nanostructured Hydrogels for Reversible Tuning of Cell Interactions.

Reactive electrospinning is demonstrated as a viable method to create fast-responsive and degradable macroporous thermoresponsive hydrogels based on poly(oligoethylene glycol methacrylate) (POEGMA). Hydrazide- and aldehyde-functionalized POEGMA precursor polymers were coelectrospun to create hydrazone cross-linked nanostructured hydrogels in a single processing step that avoids the need for porogens, phase separation-driving additives, or scaffold postprocessing. The resulting nanostructured hydrogels can respond reversibly and repeatedly to changes in external temperature within seconds, in contrast to the minutes-to-hours response time observed with bulk hydrogels. Furthermore, nearly quantitative cell delamination can be achieved within 2 min of incubation at 4 °C, resulting in the recovery of as many or more (as well as more proliferatively active) cells from the substrate relative to the conventional trypsinization protocol. The combined macroporosity, nanoscale feature size, and interfacial switching potential of these nanostructured hydrogels thus offer promise for manipulating cell-hydrogel interactions as well as other applications in which rapid responses to external stimuli are desirable.

Review on Alternative Route to Acrolein through Oxidative Coupling of Alcohols

Oxidative coupling of alcohols using methanol and ethanol, which can both be made renewable, is an attractive route to produce acrolein (propenaldehyde) in a single-step process. Currently acrolein is produced by direct oxidation of fossil propylene, and catalytic double dehydration of glycerol has been also investigated up to pilot scale. Although glycerol is an attractive feedstock, it suffers of several drawbacks. Addressing the limitations of both routes, the oxidative coupling of alcohols combines an exothermic oxidation and cross-aldolization. The best performing catalysts so far combine redox and acid/base sites. Reviewing the academic and patent literature, the present paper also addresses the economic analysis, to highlight the potential of this reaction at a yield from 70%, and at two different plant scales. The analysis has been made to guide further research, with the remaining technical problems to solve. Improved selectivity contributing to reduce the amount of equipment and the investment cost should be the prime target.

Graphene-reinforced polymer matrix composites fabricated by in situ shear exfoliation of graphite in polymer solution: processing, rheology, microstructure, and properties

Effective methods are needed to fabricate the next generation of high-performance graphene-reinforced polymer matrix composites (G-PMCs). In this work, a versatile and fundamental process is demonstrated to produce high-quality graphene-polymethylmethacrylate (G-PMMA) composites via in situ shear exfoliation of well-crystallized graphite particles loaded in highly-viscous liquid PMMA/acetone solutions into graphene nanoflakes using a concentric-cylinder shearing device. Unlike other methods where graphene is added externally to the polymer and mixed, our technique is a single step process where as-exfoliated graphene can bond directly with the polymer with no contamination/handling. The setup also allows for the investigation of the rheology of exfoliation and dispersion, providing process understanding in the attainment of the subsequently heat injection-molded and solidified G-PMC, essential for future manufacturing scalability, optimization, and repeatability. High PMMA/acetone concentration correlates to high mixture viscosity, which at large strain rates results in very-high shear stresses, producing a large number of mechanically-exfoliated flakes, as confirmed by liquid-phase UV–visible spectral analysis. Raman spectroscopy and other imaging evince that single- and bi-layer graphene are readily achieved. Nevertheless, a limit is reached at high mixtures viscosities where the process becomes unstable as non-Newtonian fluid behavior (e.g. viscoelastic) dominates the system. Characterization of microstructure, morphology, and properties of this new class of nanostructured composites reveals interesting trends. Observations by transmission electron microscopy, scanning electron microscopy, and helium ion microscopy of the manufactured G-PMCs show uniform distributions of unadulterated, well-bonded, discontinuous, graphene nanoflakes in a PMMA matrix, which enhances stiffness and strength via a load-transfer mechanism. Elastic modulus of 5.193 GPa and hardness of 0.265 GPa are achieved through processing at 0.7 g ml−1 of acetone/PMMA for 1% wt. starting graphite loading when injected into a sample mold at 200 °C. Mechanical properties exhibit 31% and 28.6% enhancement in elastic modulus and hardness, respectively, as measured by nano-indentation.