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Amino-functionalized polypropylene nonwoven/graphene oxide (GO) hybrid material (PP-g-DMAEMA/GO) with dual-scale channels structure was fabricated via irradiation polymerization and self-assembly method for rapid removal of 7 kinds of organic pollutants from water. The GO sheets tethered to grafted branches of dimethylaminoethyl methacrylate (DMAEMA) on PP fiber surface could form nanochannels between GO and fiber. Meanwhile, polypropylene nonwoven could provide the backbone for building micron-channels. The overlapped and intertwined structure of PP-g-DMAEMA/GO with many channels assures water permeating fluently, and the GO could capture quickly the organic pollutants carried by water both in batch and filtration process. The obtained PP-g-DMAEMA/GO could keep 74.3% of the adsorption performance of GO, which demonstrated two sides of GO could afford accessible binding sites. While the flow rate reach 40 mL/min, the PP-g-DMAEMA/GO was able to effectively remove Bisphenol A (BPA) with the contact time of 3.4 s. Moreover, the PP-g-DMAEMA/GO could simply be recovered by washing with ethanol solution. We conclude the paper that the facile synthesis of PP-g-DMAEMA/GO exploiting inexpensive PP nonwoven offer high water permeability, solving the separation problem of GO, and promising potential for applications of GO for water applications.

A novel dual-layer composite membrane, which has integrated filtration and adsorption, was prepared from polyvinylidene fluoride (PVDF) membrane and functionalized polypropylene (PP) non-woven fabric (or PP-g-SA-HEA) support. Stearyl acrylate (SA) and hydroxyethyl acrylate (HEA) were first grafted onto the original PP non-woven fabric using ultraviolet (UV) irradiation graft polymerization. The resulting functionalized PP non-woven fabric was then coated with PVDF membrane via phase inversion. The characterization showed that the surface density and wettability of PP-g-SA-HEA varied with total amount and proportion of the grafted SA and HEA. At appropriate degree of grafting, the composite membrane formed a clear dual layers structure without any delamination and had enhanced mechanical properties. The dual-layer composite membrane was applied in filtration to remove low-concentration endocrine disrupting compounds (EDCs) from water. The results showed that the membrane was able to effectively remove bisphenol A (BPA) and other EDCs by adsorbing onto the PP-g-SA-HEA support layer. Compared to the single layer PVDF membrane, the filtration performance of the dual-layer composite membrane was not affected. In addition, the used membranes could be simply recovered by washing with mixed deionized water–ethanol solution.

In this study, a novel adsorbent (PP-g-GMA-(n-OA)) was designed and synthesized via grafting polymerization of glycidyl methacrylate (GMA), and subsequent amination modification of 4-n-Octylaniline (n-OA) on the surface of polypropylene nonwoven. The morphological structure, composition and wettability of the PP-g-GMA-(n-OA) were thoroughly characterized by SEM, FT-IR, XPS, water contact angle. Results elucidated that the hydrophilic hydroxyl/amino groups and hydrophobic aromatic rings were successfully introduced onto the surface of PP-g-GMA-(n-OA), which could be selectively bind similar functional groups of phthalic acid esters (PAEs) by different adsorption interactions to achieve more satisfactory adsorption efficiently. Compared to unmodified PP nonwoven and several other reported adsorbents, PP-g-GMA-(n-OA) exhibited relatively high adsorption capacity for dioctyl phthalate (DOP) and dibutyl phthalate (DBP) (272.4 mg/g and 184.9 mg/g, respectively). The Freundlich isotherm model can be satisfactorily fitted the isotherm data, elucidating that it was a multilayer heterogeneous adsorption. The thermodynamic parameters confirmed the adsorption was spontaneous and exothermic process. In additional, the adsorbent still exhibited excellent adsorption capacity after multiple desorption/adsorption cycles. Adsorption mechanism was also investigated using the results of adsorption behavior and spectrum analyses after adsorption, which demonstrated that synergistic effect of π-π interaction, hydrophobic interaction and hydrogen bonds, especially π-π interaction played a dominated role in DOP and DBP adsorption. The current study provided a strategy for design and fabrication of high effective and low-cost adsorbents for remove of target contaminants from wastewater.