Polyetherimide (PEI) is a widely applied as engineering plastic in the electronics, aerospace, and automotive industries but the disadvantages of extremely low conductivity, atmospheric moisture absorption, and poor fluidity at high temperature limits its application. Herein, commercial multi-walled carbon nanotubes (MWCNTs) were modified with a long alkyl chain molecule, octadecylamine (ODA), to produce a uniform dispersion in commercial PEI matrices. Both covalent and noncovalent modification of MWCNTs with ODA, were prepared and compared. Modified MWCNTs were incorporated in PEI matrices to fabricate nanocomposite membranes by a simple casting method. Investigating mechanical properties, thermal stability, and conductivity of the polyetherimide (PEI)/MWCNT composites showed a unique combination of properties, such as high electrical conductivity, high mechanical properties, and high thermal stability at a low content of 1.0 wt % loading of ODA modified MWCNTs. Moreover, electrical resistivity decreased around 10 orders of magnitude with only 0.5 wt % of modified MWCNTs.

We present a detailed experimental study on how magnetic and electronic properties of Rb,K-intercalated C₆₀ encapsulated inside carbon nanotubes called peapods can be derived from ¹³C nuclear magnetic resonance investigations. Ring currents do play a basic role in those systems; in particular, the inner cavities of nanotubes offer an ideal environment to investigate the magnetism at the nanoscale. We report the largest diamagnetic shifts down to −68.3 ppm ever observed in carbon allotropes, which is connected to the enhancement of the aromaticity of the nanotube envelope upon intercalation. The metallization of intercalated peapods is evidenced from the chemical shift anisotropy and spin-lattice relaxation (T₁) measurements. The observed relaxation curves signal a three-component model with two slow and one fast relaxing components. We assigned the fast component to the unpaired electrons charged C₆₀ that show a phase transition near 100 K. The two slow components can be rationalized by the two types of charged C₆₀ at two different positions with a linear regime following Korringa behavior, which is typical for metallic system and allow us to estimate the density of sate at Fermi level n(E_F).

On the road to developing more sustainable and cost-efficient carbon fibres (CFs), replacing the conventional polyacrylonitrile (PAN) precursor with polyethylene (PE) is a promising alternative. Yet most PE-CF studies focus on fibre properties at laboratory or pilot scale and largely overlook scalability—especially in melt-spinning, where precursor filament counts have typically been limited to 32–100, far below industrial CF tows (1000–48,000). This study addresses that gap by (i) modifying a staple-fibre melt-spinning line (MSFP) to directly produce a 10,000-filament PE precursor and (ii) demonstrating inline filament merging on an industrial yarn (IDY) plant at Institut für Textiltechnik (ITA) as a pragmatic scale-up route. Direct 10 k spinning proved technically feasible but did not meet convertibility targets owing to inhomogeneous extrusion and quench: the MSFP precursor showed 18.1 ± 2.0 µm filament diameter, 21.9 ± 3.8 cN/tex tenacity and 130.8 ± 40.8% elongation (total solid draw ratio 2.02). In contrast, the IDY route delivered a fine and uniform precursor with a 9.43 ± 0.02 µm filament diameter, 38.42 ± 0.43 cN/tex tenacity, 15.91 ± 0.76% elongation, and 15.32 ± 1.16% shrinkage at 120 °C (total solid draw ratio 4.55). After discontinuous sulfonation, TGA indicated superior cross-linking of the IDY precursor (≈15% mass loss at 400–600 °C) versus MSFP (≈18%). Inline merging doubled filament count inline and small-scale plying enabled a 6 k tow. Transferring the IDY precursor into continuous sulfonation and carbonisation yielded PE-based CF with a filament diameter < 8.5 µm, tensile strength up to 2.0 GPa, tensile modulus up to 170 GPa, and elongation at break up to 1.75%, without surface defects. The results establish a clear scale-up roadmap: prioritise homogeneous fine-filament extrusion at low throughputs, co-develop segmented quench, and use a stepwise strategy (1–2 k filaments → inline merging → ≥6 k) to enable industrially relevant, cost-effective PE-based CF production.

In this paper, hydrophilic silica particles (250 nm and 800 nm) were synthesized using the well-established Stöber method. The particles and their mixtures were chemically treated to achieve hydrophobic properties, confirmed using the sessile drop technique. Mild steel sheets were prepared, sand blasted and cleaned to the required surface roughness and cleanliness, verified by established quantitative methods. Two resins, Jotamastic 80 and Penguard FC, were applied as primer and topcoat to the required thickness. The resulting films were evaluated qualitatively and by optical interferometry and micrograph analysis. Samples were then coated with selected combinations of hydrophobic particles to form homogeneous coatings, and their hydrophobicity was assessed. The highest contact angle was obtained for a mixture of 75% 250 nm and 25% 800 nm particles, with other combinations showing contact angles between 130° and 140°. Optimal adhesion and hydrophobic performance were achieved when particle/ethanol suspensions were sprayed 2.5 h after topcoat application. The hydrophobic structure was best developed after 24–48 h of drying. Surface morphology was examined using Scanning Electron Microscopy, and the results are discussed.