Search Results (2)

Due to the non-polar and chemically inert nature of carbon fiber surfaces, the interfacial bonding strength between carbon fibers and norbornene-polyimide (PI-NA) resin matrix is relatively weak. To address this issue, this study constructed a composite coating on the carbon fiber surface and proposed a novel method to build robust interfaces based on multiple interfacial interactions, thereby effectively enhancing the interfacial properties between carbon fibers and PI-NA resin. Inspired by mussel adhesive proteins, this study established a multi-level synergistic interfacial reinforcement system by sequentially constructing a C-PEI@OPDA coating, in situ growing zinc oxide nanorods (ZW) arrays, and grafting 3-mercaptopropyltrimethoxysilane (MPS) onto carbon fiber surfaces. The C-PEI@OPDA coating, rich in amino (–NH₂) and hydroxyl groups (–OH), enhanced adhesion to carbon fibers and adsorbed Zn²⁺ via coordination interactions to provide nucleation sites for ZW growth. Meanwhile, the active hydrogen in the coating promoted the crosslinking of PI-NA resin, thereby increasing the resin crosslinking density in the interfacial region. The vertically aligned ZW significantly increased surface roughness, enhanced mechanical interlocking effects, and provided secondary reaction sites for MPS grafting. The thiol groups (–SH) in MPS formed covalent bonds with PI-NA resin through thiol-ene click reactions, further strengthening interfacial bonding. The results showed that the ILSS, IFSS, and flexural strength of C-PEI@OPDA/ZW/MPS modified carbon fiber composites reached 75.15 MPa, 102.93 MPa, and 1735.56 MPa, representing improvements of 39.09%, 48.79%, and 31.16%, respectively. This study effectively enhanced the carbon fiber-reinforced polymer composites interfacial bonding strength through the synergistic effects of hydrogen bonding, mechanical interlocking, chemical bonding, and increased resin crosslinking density. Full article

In case of an incident in the nuclear industry or an act of war or terrorism, the dissemination of plutonium could contaminate the environment and, hence, humans. Human contamination mainly occurs via inhalation and/or wounding (and, less likely, ingestion). In such cases, plutonium, if soluble, reaches circulation, whereas the poorly soluble fraction (such as small colloids) is trapped in alveolar macrophages or remains at the site of wounding. Once in the blood, the plutonium is delivered to the liver and/or to the bone, particularly into its mineral part, mostly composed of hydroxyapatite. Countermeasures against plutonium exist and consist of intravenous injections or inhalation of diethylenetetraminepentaacetate salts. Their effectiveness is, however, mainly confined to the circulating soluble forms of plutonium. Furthermore, the short bioavailability of diethylenetetraminepentaacetate results in its rapid elimination. To overcome these limitations and to provide a complementary approach to this common therapy, we developed polymeric analogs to indirectly target the problematic retention sites. We present herein a first study regarding the decontamination abilities of polyethyleneimine methylcarboxylate (structural diethylenetetraminepentaacetate polymer analog) and polyethyleneimine methylphosphonate (phosphonate polymeric analog) directed against Th(IV), used here as a Pu(IV) surrogate, which was incorporated into hydroxyapatite used as a bone model. Our results suggest that polyethylenimine methylphosphonate could be a good candidate for powerful bone decontamination action. Full article