Three-dimensional printing is promising in the pharmaceutical industry for personalized medicine, on-demand production, tailored drug loading, etc. Pressure-assisted microsyringe (PAM) printing is popular due to its low cost, simple operation, and compatibility with heat-sensitive drugs but is limited by ink formulations lacking the essential characteristics, impacting their performance. This study evaluates inks based on sodium alginate (SA), hydroxypropyl cellulose (HPC H), and hydroxypropyl methylcellulose (HPMC K100 and K4) for PAM 3D printing by analyzing their rheology. The formulations included the model drug Fenofibrate, functional excipients (e.g., mannitol, polyethylene glycol, etc.), and water or water–ethanol mixtures. Pills and thin films as an oral dosage were printed using a 410 μm nozzle, a 10 mm/s speed, a 50% infill density, and a 60 kPa pressure. Among the various formulated inks, only the ink containing 0.8% SA achieved successful prints with the desired shape fidelity, linked to its rheological properties, which were assessed using flow, amplitude sweep, and thixotropy tests. This study concludes that (i) an ink’s rheological properties—viscosity, shear thinning, viscoelasticity, modulus, flow point, recovery, etc.—have to be considered to determine whether it will print well; (ii) printability is independent of the dosage form; and (iii) the optimal inks are viscoelastic solids with specific rheological traits. This research provides insights for developing polymer-based inks for effective PAM 3D printing in pharmaceuticals.

High surface area graphitic mesoporous carbons (M‐mGMC; M=Ni, Fe, Co or Ni‐Fe) were synthesized via catalytic graphitization using a hard template based synthesis method. In house prepared SBA‐15 silica material was impregnated with metal precursors to obtain M/SBA‐15, template for M‐mGMC synthesis. These materials were studied using different material characterization techniques, such as nitrogen adsorption desorption (BET), X‐ray diffraction (XRD) analysis, Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Specific surface area ranging from 1,227.9 m² g⁻¹ to 1,320.7 m² g⁻¹ was observed for four M‐mGMCs. Raman spectroscopy, XPS and wide angle XRD suggested presence of graphitic structure in these materials along with disorders. Electrocatalytic performance of these materials along with conventional carbon black (Vulcan XC‐72) were evaluated in a single‐stack proton exchange membrane fuel cell (PEMFC). Pt/NiFe‐mGMC exhibited enhanced electrocatalytic activity compared to Pt/Ni‐mGMC, Pt/Fe‐mGMC and Pt/Co‐mGMC electrocatalysts. However, Pt/NiFe‐mGMC lacked adequate proton transport in membrane electrode assembly (MEA) compared to Pt/Vulcan XC‐72. This exploratory study showed that NiFe‐mGMC may find application as electrocatalyst support material in PEMFC.

Over the years, several different methods have been developed by modifying the conventional electroless plating (CEP) technique to fabricate dense thin Pd composite membranes with high H₂ permselectivity. In this study, Pd composite membranes on macroporous stainless steel substrate (MPSS) were fabricated using CEP and novel surfactant induced electroless plating (SIEP) methods. The structural characteristics of CEP and SIEP fabricated Pd membranes were investigated before and after the heat treatment using SEM, XRD, EDS, and AFM techniques. The H₂ permselectivity performance of the SIEP membranes was compared with that of CEP at different temperatures and trans-membrane pressures in the range of 523-823 K and 20-100 psi, respectively. The long-term thermal stability test of SIEP fabricated membranes was carried out on two different membranes, fabricated on MPSS substrates with and without oxide layer at 15 psi trans-membrane pressure and thermal cycling of 573-723-573 K. The microstructure analysis revealed that SIEP membranes have finer grains and diffused grain boundaries resulting in uniform, smooth, continuous, and pinhole free Pd-film. The SIEP membrane showed eight-fold higher H₂ flux (1.7172 mol/m²/s) and four-fold higher H₂ selectivity (~148) at 823 K and 100 psi trans-membrane pressure, compared to CEP membrane. Pd/MPSS membrane subjected to test for long-term performance and thermal cycling showed stable performance up to 1200 h while maintaining infinite H₂ selectivity. Interestingly, although the thickness of Pd/oxi-MPSS (13.49 µm) membrane was higher than that of Pd/MPSS (11.6 µm) membrane, the H₂ flux of Pd/oxi-MPSS membrane was two times higher than that of Pd/MPSS, attributed to the effective action of oxide layer as diffusion barrier.

In this work, high-surface area graphitized ordered mesoporous carbon (M-mOMC, M = Fe, Co, Ni) materials were synthesized using M-SBA-15 template for PEM fuel cell electrocatalysts support. These materials were characterized by BET, XRD, TEM, TGA-DSC and Raman spectroscopy. Fuel cell polarization study indicated that of the three Pt/M-mOMCs, nickel modified mOMC’s performance was superior over Fe and Co modified mOMCs and outperformed Pt/OMC. XRD and Raman Spectroscopy studies revealed that graphitization of the OMC using transition metals results in some defects in the ordered structure. The performance of these M-mOMCs as electrocatalyst support for PEM fuel cell application is reported in this paper.

Background/Objectives: Interest in 3D printing oral thin films (OTFs) has increased substantially. The challenge of 3D printing is film printability, which is strongly affected by the rheological properties of the ink and having suitable mechanical properties. This research assesses the suitability of sodium starch glycolate (SSG), a swellable cross-linked biopolymer, on ink rheology and the film’s mechanical properties. Methods: A water-based ink comprising sodium alginate (SA), the drug fenofibrate (FNB), SSG, glycerin, and polyvinylpyrrolidone (PVP) was formulated, and its rheology was assessed through flow, amplitude sweeps, and thixotropy tests. Films (10 mm × 15 mm × 0.35 mm) were 3D-printed using a 410 µm nozzle, 50% infill density, 60 kPa pressure, and 10 mm/s speed, with mechanical properties (Young’s modulus, tensile strength, and elongation at break) analyzed using a TA-XT Plus C texture analyzer. Results: The rheology showed SSG-based ink has suitable properties (shear-thinning behavior, high viscosity, higher modulus, and quick recovery) for 3D printing. SSG enhanced the rheology (viscosity and modulus) of ink but not the mechanical properties of film. XRD and DSC confirmed preserved FNB crystallinity without polymorphic changes. SEM images showed surface morphology and particle distribution across the film. The film demonstrated a drug loading of 44.28% (RSD 5.62%) and a dissolution rate of ~77% within 30 min. Conclusions: SSG improves ink rheology, makes it compatible with 3D printing, and enhances drug dissolution (formulation F-5). Plasticizer glycerin is essential with SSG to achieve the film’s required mechanical properties. The study confirms SSG’s suitability for 3D printing of OTFs.

Polycrystalline palladium (Pd) was deposited on micro-porous stainless steel (MPSS) substrate using a suitable surfactant of various concentrations in the electroless plating process. The micro-structural characterization was carried out using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray diffraction (XRD). The concentrations of the surfactant were chosen as a function of critical micelle concentration (CMC) in order to elucidate the interaction of the surfactant in solid-liquid and solid-gas interface during grain coarsening. It appears that during electro-crystallization, the driving force between the newly formed crystallite and the originally coarsed grains depends on the relative size and crystalline configuration of the newly formed crystallite. This crystallite on the other hand is affected by the localized over potential, the presence of active nucleating particles, and the texture of MPSS surface and operating conditions. The size of the newly formed grain is smaller when the concentration of the surface-active agents is relatively higher. It suggests that the surfactant active polar group inherently participates in the reaction/deposition process and effectively activates the process of grain nucleation and agglomeration in electro-crystallization. The membranes of different grain sizes were fabricated in the presence of the cationic surfactant DTAB (dodecyltrimethyiammonium bromide) of various concentrations. DTAB concentration is expressed in critical micelle concentration (CM), which ranged from CMC × ½ to CMC × 4. Fabricated membranes of different grain size and distribution were also studied for hydrogen permeability and selectivity. Results show that membranes with agglomerated grains (higher grain size) possess relatively higher permeability and selectivity.