Tissue engineering scaffolds have been dedicated to regenerating damaged tissue by serving as host biomaterials for cell adhesion, growth, differentiation, and proliferation to develop new tissue. In this work, the design and fabrication of a biodegradable bilayer scaffold consisting of a ternary PLLA/PCL/CAB blend film layer and a PLGA/curcumin (CC) electrospun fiber layer were studied and discussed in terms of surface morphology, tensile mechanical properties, and molecular interactions. Three different compositions of PLLA/PCL/CAB—60/15/25 (TBF1), 75/10/15 (TBF2), and 85/5/10 (TBF3)—were fabricated using the solvent casting method. The electrospun fibers of PLGA/CC were fabricated using chloroform (CF) and dimethylformamide (DMF) co-solvents in 50:50 and 60:40 volume ratios. Spherical patterns of varying sizes were observed on the surfaces of all blend films—TBF1 (17–21 µm) > TBF2 (5–9 µm) > TBF3 (1–5 µm)—caused by heterogeneous surfaces inducing bubble nucleation. The TBF1, TBF2, and TBF3 films showed tensile elongation at break values of approximately 170%, 94%, and 43%, respectively. The PLGA/CC electrospun fibers fabricated using 50:50 CF:DMF had diameters ranging from 100 to 400 nm, which were larger than those of the PLGA fibers (50–200 nm). In contrast, the PLGA/CC electrospun fibers fabricated using 60:40 CF:DMF had diameters mostly ranging from 200 to 700 nm, which were larger than those of PLGA fibers (200–500 nm). Molecular interactions via hydrogen bonding were observed between PLGA and CC. The surface morphology of the bilayer scaffold demonstrated adhesion between these two solid surfaces resembling “thread stitches” promoted by hydrophobic interactions, hydrogen bonding, and surface roughness.

This study presents the development of biocompatible antistatic nanofibrous composite yarns via a scalable AC electrospinning method, incorporating ultrasonicated expanded graphite (uEG) and PEDOT:PSS into polyamide (PA), polyvinyl butyral (PVB), and polyvinyl alcohol (PVA) matrices. TGA confirmed high filler retention during electrospinning. Electrical measurements showed that the addition of uEG and micrographite reduced single-yarn resistance by up to two orders of magnitude compared with neat polymers, yielding normalised resistivities as low as ~10⁵–10⁶ Ω·m and conductivities in the 10⁻⁷–10⁻⁵ S/m range, suitable for antistatic and sensing applications. However, the large filler–fibre size mismatch and highly porous yarn architecture limited the formation of continuous conductive networks, and mechanical tests revealed strength reductions of up to 70–80% at the highest PVB filler loadings. XRD confirmed a reduction in crystallinity with filler addition, PEDOT:PSS enhanced polymer chain nucleation and thus mechanical properties. Cytotoxicity assays demonstrated that uEG, micrographite, and PEDOT:PSS significantly improved cell viability compared with non-crosslinked PVA, with several PVB-based and PVA/uEG composites showing viability statistically comparable to the DMEM control (>70%) while remaining significantly higher than the Triton positive control. Overall, this work establishes an AC-electrospun route to antistatic nanofibrous yarns that combine high filler retention with enhanced biocompatibility.

Polyester resin composites containing expanded graphite often exhibit reduced mechanical strength due to the porous structure of the filler. The aim of this study was to enhance mechanical performance without compromising electrical behaviour. Although carbon fibre and expanded graphite are chemically identical carbon allotropes, their distinct morphologies motivated the use of carbon fibre to reinforce expanded graphite-filled polyester composites. To examine the role of expanded graphite porosity, ultrasonicated EG was used to produce exfoliated, lower-porosity particles, while vacuum processing was applied to remove entrapped air prior to curing. Adding 0.5–5 wt% milled carbon fibre increased electrical conductivity by up to three orders of magnitude relative to neat polyester while maintaining 70–80% of the original specific strength at moderate fibre contents. Ultrasonicated EG reduced tensile strength by more than 50% at 5 wt% loading and decreased conductivity due to additional grain boundary formation. Vacuum-processed EG not only provided slight mechanical enhancements but also significantly improved electrical properties by lowering surface resistance by 6–10 orders of magnitude, reaching the tens-of-Ω range at 3–5 wt% EG. This performance is comparable to previously reported conductive EG/polymer systems, which exhibit surface resistances of 10–10² Ω at 5 wt% EG. This systematic comparison offers practical guidelines for balancing conductive percolation and mechanical reinforcement in expanded graphite polyester composites.