Monofunctional (methacrylolsobutyl) and multifunctional (methacryl) polyhedral oligomeric silsesquioxane (POSS) were successfully grafted on a carbon fiber (CF) surface to enhance the interfacial strength of CF reinforced unsaturated polyester resin (UPR) composites. The silicon containing functional groups were obviously increased on the CFs after the successful grafting of POSS onto the CF surface. Both kinds of POSS were uniformly grafted on the CF surface and the surface roughness of the CFs grafted with methacryl POSS and methacrylolsobutyl POSS was almost the same (131.6 and 129.6 nm) but much higher than that of the as-received CFs (57.9 nm). Dynamic contact angle analysis of the CFs grafted with both POSS showed almost the same surface energy but higher than that of the as-received CFs. After being grafted with methacrylolsobutyl POSS, the interlaminar shear strength of the composites was 62 MPa, increased by 31.9%, however, in terms of methacryl POSS the value was 67 MPa, increased by 42.6% compared with that of the as-received CFs (47 MPa). The interfacial shear strength (IFSS) of the composites with methacryl POSS grafted CFs (93 MPa) was significantly increased by 102.2% compared with the composites with the as-received CFs (46 MPa) and is even higher than that of the composites with methacrylolsobutyl POSS grafted CFs (87 MPa). The impact energy of 1.72 J for the composites with methacryl POSS grafted CFs is higher than that of the composites with as-received CFs (1.00 J) and methacrylolsobutyl POSS grafted CFs (1.43 J).

Industrial wastewater containing dyes has led to global water scarcity and been severely damaging to human health. The demand for the exploration of practical and cost-effective dye removal treatment is exploding. Here, we developed an ultrahigh-capacity adsorbent for dye removal, especially for Congo red. We synthesized a polyamide amine dendrimer aerogel based on aramid nanofibers (ANFs) through an effective method, which showed a specific area larger than the ANF aerogel by 38.1% due to the formation of polyamide amine dendrimer nanofibers bridging between ANFs. Moreover, the key mechanism of CR adsorption is changed from π–π stacking to H-bond interactions because of abundant N and O atoms in polyamide amine molecules, which make full use of the adsorbent surface space. As a result, the maximum of the CR adsorption capacity is 1957.881 mg g⁻¹ and this value is still as high as 1567.063 mg g⁻¹ even after five adsorption–desorption cycles. As we know, there are few reported adsorbents showing such high adsorption capacity for CR. And in a real wastewater system, the adsorption performance of CR changed slightly. Therefore, as an effective adsorbent, this composite nanofiber aerogel is very promising in the field of wastewater treatment.