An attempt at the treatment of the waste fiber (WF) from the wind turbine blade (WTB) was made through the modifier of dopamine hydrochloride and the compound modifier of dopamine hydrochloride and 2,5-dihydroxy terephthalic acid or 3,4-dihydroxy cinnamic acid or 3,4-dihydroxy benzonitrile, corresponding to obtain four modified waste fibers (MWF1, MWF2, MWF3, and MWF4). The MWFs samples’ microstructure properties were characterized using SEM, EDS, XPS, FTIR analyses, and water contact angle tests. The results revealed that all the MWF surfaces were wrapped by a distinct coating layer and had different elemental compositions and chemical groups, demonstrating the significant effect of the four modifications on the WF surfaces. The hydroxyl, amino, or nitrile groups were grafted onto the WF surfaces causing improvement of the hydrophilicity and reactivity. Furthermore, all the MWFs as the reinforced materials were incorporated into the industrial waste phosphogypsum (PG) to manufacture the phosphorous-building gypsum composites (PBGC). The effects on the micro-morphology and mechanical properties of the PBGC were evaluated. The results also show the improvement in flexural and compressive strength with the addition of MWFs into the PBGC, due to the enhancement of the compactness between the MWF and phosphogypsum matrix. In particular, the effects of three compound modifiers on the flexural and compressive strength are more significant. The highest flexural and compressive strength was contributed by the PBGC-MWF4 with 2% dosage using a compound modifier of dopamine hydrochloride and 3,4-dihydroxy benzonitrile, which were enhanced 61.04% and 25.97% compared with the PBG.

Nanostructured magnetic particles are promising candidate materials for oil/water separation, demulsification, and detoxification. A nanometer-sized magnetic composites with superhydrophobicity and superoleophilicity surface is produced via self-assembly synthesis using Sol-Gel method. The oil/water separation performances of as prepared Methyltrimethoxysilane (MTMS)/Diethoxymethylsilane (DEMS)-Fe3O4 nanocomposite particles (MTMS/DEMS-Fe3O4 NCPs) nanocomposites as demulsifications were investigated for oil removal. The properties of the composite were characterized using AFM, SEM, FTIR, XRD, Raman, TGA VSM and Interfacial Tension Analysis. The results show that MTMS/DEMS-Fe3O4 NCPs are composed of Fe3O4-SiO2-CH3. More interestingly, the MTMS/DEMS-Fe3O4 NCPs samples showed higher saturation magnetization values (Ms = 78.9 emu/g) compared to the pure Fe3O4 NPs (Ms = 69.6 emu/g). The demulsification efficiency of the MTMS/DEMS-Fe3O4 particles was found to be higher to that of Fe3O4 particles under magnetic control. The effects of Fe3O4 nanoparticles concentration on demulsification, oil absorbency, and oil/water selectivity were also investigated. The materials have good superhydrophobicity/superoleophilicity (CAwater ≈ 160° and CAoil ≈ 0°) and excellent magnetic responsivity. It also show very high efficiency demulsification to oil-in-water emulsions and could quickly absorb floating oils on the surface and heavy oils on the bottom driven by magnet. In particular, the demulsification efficiency could reach about 97.5% at room temperature. Moreover, the preparation process of Superhydrophobic-superoleophilic particles is completely fluoropolymer-free. More importantly, the mixture of oil and demulsifiers could be seperated by ethanol and magnet, which is beneficial to the recycle. With great demulsification and recyclability performance, the superhydrophobic and superoleophilic micro/nano Fe3O4 particles display great promise to achieve industrial applications in the future.