Abstract Chronic wounds remain a major clinical challenge due to prolonged inflammation, infection, and delayed tissue regeneration. This study developed and characterized porous scaffolds based on chitosan, collagen, and ethanolic extract of Jatropha mollissima aimed at wound dressing applications. Scaffolds were prepared by lyophilization using different chitosan/collagen ratios, with and without plant extract incorporation. Physicochemical, morphological, and biological properties were evaluated by FTIR, optical microscopy, SEM, swelling, enzymatic biodegradation, and in vitro cytotoxicity assays. The results demonstrated good interaction between chitosan and collagen, the presence of porous and interconnected structures, swelling indices above 740%, controlled biodegradation, and absence of cytotoxic effects. The incorporation of Jatropha mollissima extract did not compromise scaffold stability or absorbency. These findings suggest that the developed scaffolds possess characteristics of interest for wound dressing applications. However, additional studies involving quantitative porosity measurements, wettability, and mechanical characterization are required to further validate their potential for difficult-to-heal wound treatment.
Abstract Previous studies in this journal reported a two-part investigation on carbon black (CB) dispersions in LDPE films. In PART01, trimodal CB mixtures were evaluated using a Design of Experiments (DOE) to assess colorimetric and rheological properties, containing small (S) and medium (M) particles showed higher Tinting Strength (TS) with lower viscosity due to synergistic interactions. In PART02, dispersion of blend F18 was optimized during twin-screw extrusion by evaluating the Specific Mechanical Energy (SME), and the best performance was obtained at 600 rpm and 10 kg/h (0.29 kWh/kg), defined as F18-P03. In PART03, this formulation was filled with micro- (D50: 2.5 μm) or nano-CaCO3 (D50: 40 nm) at 10 and 20 wt% to reduce cost and modify mechanical properties. Although CaCO3 reduced TS, increased Filter Pressure Value (FPV) and viscosity. Nanoparticle at 10 wt% showed the best balance: Young’s modulus increased 18%, while tensile strength and deformation decreased about 8%.
Abstract The development of sustainable membranes from polymer waste is a promising strategy for wastewater treatment. This study investigated the effect of zinc oxide (ZnO) incorporation on recycled polyamide 66 (PA66) membranes prepared by the phase inversion method for oily emulsion separation. Membranes were characterized by atomic force microscopy, porosity, water absorption, pore size, contact angle, and permeation tests. ZnO promoted structural modifications, increasing roughness (140.87 nm), water absorption (76.6%), porosity (60.5%), and mean pore radius (1.85 µm) compared with pure PA66. The membrane containing 3 wt.% ZnO exhibited the highest stabilized water permeate flux (159.82 L.m-2.h-1). All membranes achieved color and turbidity removals of up to 99.88% and oil rejection above 95%, producing permeates that complied with current discharge regulations. These results demonstrate that recycled PA66/ZnO hybrid membranes are promising, sustainable candidates for efficient oily wastewater treatment.
Abstract Superhydrophobic porous membranes are materials that are used for oil-water separation. However, conventional fabrication methods present limited scalability, complex processing, and poor membrane morphology control. In this study, a modular alternative based on 3D printed membrane was investigated. Microporous membranes, composed of polypropylene (PP)/graphene nanocomposites, were fabricated by the fused filament fabrication (FFF) method and subsequently surface-modified via dip-coating, using coatings based on polydimethylsiloxane (PDMS), silica nanoparticles, and/or graphene nanosheets. Untreated pure PP membranes exhibited a water contact angle (WCA) of 117.9°, which increased to 123.3° when graphene was incorporated into the PP matrix. Besides, the surface treatment increased the membranes’ WCA up to 132.59°. Filtration tests demonstrated high oil-water separation efficiency, achieving up to 99%. These results highlight the synergism between additive manufacturing and nanostructured surface treatments.
Abstract Hydrophobically modified polyacrylamides (HMPAMs) are synthesized by incorporating styrene, a hydrophobic monomer, to address the limitations of conventional polyacrylamide (PAM) and partially hydrolyzed polyacrylamide (HPAM). These limitations, which reduce the effectiveness of polymer flooding for enhanced oil recovery, include poor shear resistance, sensitivity to salinity, chemical degradation such as polymer chain scission, and hydrolysis of acrylamide groups. In this study, the HMPAM samples are characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and oscillatory strain measurements. The results indicate that HMPAM containing a higher concentration of hydrophobic monomer (1.5 mol%) demonstrates improved shear resistance and greater thermal stability.
