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Scheme 1 The schematic illustration for preparing PES/CS, PES/CSTr and SI-PES/CSTr particles using Method 1 and Method 2, respectively.
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The application of chitosan (CS) as adsorbent was limited by its poor acidic resistance, solubility in organic solvents and miscibility with synthetic polymers. In this study, an effective way was utilized to increase the amount of CS in hybrid particles together with good acid-alkali resistance and mechanical strength. CS was chemically modified a...
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Context 1
... FTIR spectra of CS, PACS, and CSTr are shown in Fig. 1(a). Compared with the spectrum of CS, the spectrum of the PACS showed new peaks at 1715 and 1287 cm À1 , which were attributed to the C]O bonds from the imide groups and the ester bonds from a low amount of the O-phthaloyl groups, respectively. The spectrum of CSTr showed new peaks at 1659, 1597, and 1491 cm À1 , which were assigned to ...Context 2
... The spectrum of CSTr showed new peaks at 1659, 1597, and 1491 cm À1 , which were assigned to the benzene ring from triphenylmethane groups; while the peak at 1715 cm À1 for the phthaloyl groups disappeared, which indicated that the phthaloyl groups were successfully dissociated. The 1 H NMR (DMSO-d 6 ) spectra of PACS and CSTr are shown in Fig. 1(b). The peaks at 2.0 to 4.5 ppm were assigned to the hydrogens of chitosan. The peaks at 7.78 and 7.43 ppm in the spectrum of PACS were attributed to the hydrogens of the benzene ring from the phthaloyl groups; while the peaks at 7.39 and 7.26 ppm in the CSTr spectrum were assigned to the hydrogens of the benzene ring from the ...Context 3
... N-substitution or O-substitution also affected the crys- tallinity of the CS derivatives. The images of X-ray diffraction diagrams (XRD, see Fig. S1 †) showed that pristine CS had crystallinity; while the PACS was amorphous due to N-substi- tution and partial O-substitution, 23 and CSTr had partial crys- tallinity. Thus, the solubility of PACS and CSTr in organic solvents could be improved compared with CS (see Table S1 †), which provided the possibility for blending with other ...Context 4
... q e is the mass of BPA adsorbed by the unit mass aer the adsorption reaches equilibrium (mg g À1 ); C e is the equilibrium concentration of BPA (mg L À1 ); q max is the maximal adsorbed amount of the particles (mg g À1 ); and k L is the Langmuir adsorption constant. As shown in Fig. 10(a), a plot of C e /q e versus C e gives a straight line with the slope of 1/q max and the intercept C e /(q max ). All the correlation coefficient (r 2 ) were higher than 0.98 (see Table S4 †), which indicated that the adsorption of PBA on the PES/CSTr and SI-PES/CSTr particles followed the Langmuir adsorption isotherm. The Freundlich ...Context 5
... linear plot was obtained when ln q e was plotted against ln C e , as shown in Fig. 10(b), and then the parameters could be obtained (see Table S4 †). The values of the correlation coeffi- cient were higher than 0.95, and some of them reached 0.99. This indicated that the adsorption process also t this model. The above results suggested that both the monolayer Langmuir adsorption isotherm and Freundlich isotherm were ...Context 6
... Cu 2+ desorption experiments were carried out in EDTA aqueous solution (0.01 M) and hydrochloric acid aqueous solution (pH 2) using the SI-PES/CSTr-50 particles. The des- orbed ratios for three replicate times are shown in Fig. 11(a). As shown in the gure, the desorbed ratios for each time in EDTA and HCl were similar, and the total desorbed ratios were higher than 0.95. With good acid-base resistance, it suggested that the SI-PES/CSTr-50 particles aer Cu 2+ adsorption could be regen- erated easily using EDTA or HCl ...Context 7
... CR and BPA desorption experiments were carried out in ethanol solution and hydrochloric acid aqueous solution (pH 2), and the results are shown in Fig. 11(b) and (c). As shown in the gures, the rst desorbed ratios in EtOH were higher than that in HCl for both CR and BPA, since EtOH is a good solvent for CR and BPA. The total desorbed ratios could be over 0.95 in both EtOH and HCl solution, which indicated that the hybrid parti- cles aer BPA or CR adsorption could be regenerated easily ...Citations
... We afterwards compared the maximum adsorption capacity towards creatinine, uric acid and bilirubin among various adsorbents in the blood perfusion ( Fig. 3g and Table S4). It is clear that B-PES-4 microspheres displayed larger adsorption amounts than not only pure SPES microspheres, but also reported GO, rGO, carbon nanotubes (CNTs), activated carbons (ACs) based composites and natural resins, i.e. collagen, etc [13,16,[35][36][37][38][39][40][41][42][43][44]. The superior adsorption performances were also visibly illustrated in Fig. 3h. ...
... Chitosan dissolves in weak acids so chemical modifications such as cross-linking or grafting are employed to enhances its stability [16]. Researchers have extensively studied the removal of different dyes by chitosan [17], crosslinked chitosan [18], chitosan nanocomposite and chitosan blend with another polymer [13]. ...
... Chang and Juang (2004) reported that the addition of activated clay into chitosan could improve its mechanical strength, specific gravity, and adsorption capacity compared with chitosan alone. Chitosan-derivative/polyethersulfone hybrid particles with semi-interpenetrating network structures for versatile adsorption have been investigated by Wang et al. (2015). The results showed that compared with the chitosan particles, chitosan-based hybrid particles exhibited better acid-alkali resistance and mechanical properties. ...
Chitosan-based adsorbents have attracted increasing attention in water and wastewater treatment in recent years due to its abundance and low price, as well as rich amino and hydroxyl groups. However, there are some drawbacks hindering its practical use, such as low mechanical strength, low solubility in acidic mediums, low adsorption capacity, and lack of selectivity. Therefore, a variety of modification methods, including physical and chemical modifications, have been investigated to improve the physicochemical properties of chitosan. This review provides a summary of (a) the intrinsic nature of chitosan associated with its structure and physicochemical properties; (b) the preparation strategies for modified chitosan together with its characterization; (c) the application of chitosan-based adsorbents for the removal of both organic pollutants (e.g., dyes, PPCPs, PFOS, and humus) and inorganic pollutants (e.g., heavy metal ions, nitrate, phosphate, borate, and fluoride). Recent advances in the fabrication and application of chitosan-based adsorbents involving the intrinsic nature of pollutants are highlighted in this review, as well as the effects of process variables (e.g., pH, contact time, ionic strength, competitive ions, temperature), modeling (kinetics and isotherm), adsorption mechanisms, and regeneration.
... However, the applications of the adsorbent were sometimes limited by low mechanical strength, low oxidation and heat resistance. Since polyethersulfone (PES) shows outstanding oxidative, thermal and hydrolytic stabilities as well as good mechanical strength and chemical resistance [14], we have prepared various modified PES particles for versatile adsorptions such as the removal of organic dyes, heavy metal ions, bilirubin and creatinine [15][16][17][18]. Since the adsorption process usually occurred on the external surface and pore surface of particle and the impact on the inherent properties of the substrates could be minimized by surface modification, we attempt to use aqueous surface modification to fabricate adsorbents directly by mussel-inspired method [19]. ...
... Anionic and cationic dyes could harm human health by entering into the food chain [3]. In the present study, CR and MB were chosen as model anionic and cationic dyes, respectively [16]. The CR and MB adsorption amounts per unit mass of particles are shown in Fig. 6(a) and the characterization of the particles before and after adsorption are shown in Fig. S1. ...
The removal of toxins is important due to the damage to aquatic environment. In this work, a facile and green approach based on mussel-inspired coatings was used to fabricate amino-coated particles via the reaction between amine and catechol, using hexanediamine as the representative amine. The particles were characterized by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), thermo gravimetric analysis (TGA), and scanning electron microscopy (SEM). The particles showed selective adsorption capability to Congo red (CR) and the adsorption process fitted the pseudo-second-order model, the intraparticle diffusion model, the Langmuir isotherm, the Freundlich isotherm and the Sips isotherm well. Furthermore, this approach was verified to have applicability to various amines such as diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA), and the amino-coated particles exhibited diverse adsorption capacities to CR, Cu²⁺ and bilirubin. Considering that the approach is easy to operate and the whole preparation process is in an aqueous solution, it is believed that the facile, green and economical approach has great potential to prepare particles for wastewater treatment.
... Chitosan comes from shellfish, and is abundant natural biopolymer. It has many applications in drug delivery [20][21][22][23][24], biomimetic nanocomposite [25], cancer diagnosis [26], selective adsorption and separation of guest molecules [27], versatile adsorptions of toxins [28], heavy metal ions removal from aqueous solution [29][30][31], antimicrobial [32][33][34][35], nanocatalyst [36], biosensor [37], multifunctional films [38], et al. ...
Since graphene was discovered, the biomimetic materials with laminated structure (such as, shellfish) had become one of the research-hot fields. Chitosan comes from shellfish, and was considered as a very promising abundant natural biopolymer. It holds not only outstanding mechanical properties, film-forming technology and low cost, but also has good applications in environmental fields due to its excellent adsorption properties to a broad range of organic pollutants and some heavy metal ions. Preparation of biomimetic materials with laminated structure utilizing chitosan have many advantages, however, to improve functional properties of chitosan based biomimetic materials is still a great challenge. Graphene has various applications, including storage energy devices, hydrogen production with photo-catalysts, and environmental fields because of its high charge mobility and good mechanical properties. However, graphene and its oxide have difficult re-dispersion properties in fabrication of nanocomposite. In this paper, the nanosheets stacking of metal oxide and grapheme oxide with aid of chitosan was carried out. Several characterizations were examined by SEM (scanning electron microscopy), XRD (X-ray diffraction), ultraviolet-visible spectroscopy (UV-Vis), and Fourier-Transform Infrared (FTIR) spectra. Photocatalytic tests were examined by selecting typical organic pollutants. The photoconductivity response of nanocomposite film to visible light and 808 nm laser with low-power were investigated based on interdigital electrodes of Au on flexible PET (polyethylene terephthalate) film substrate. The results indicated that the organic-inorganic film not only had wide visible light and NIR (near-infrared) responses, but also had good removal ability to organic pollutants. The nanocomposite film also exhibited clearly photo-response to visible light and 808 nm laser. It would be potential good applications in self-cleaning film, nanocoating, et al.
... PES, the matrix material of the particles, showed excellent cytocompatibility and blood compatibility as mentioned in early reports [44][45][46], In addition, the membranes containing PGMA and the particles with amino groups had been prepared and showed good blood compatibility in our previous studies [22,47]. So we predict that inflammatory reaction of our functional PES particles is supposed to be at acceptable level when they are used for extracorporeal hemoperfusion. ...
In this study, polyethersulfone/poly (glycidyl methacrylate) particles are prepared via in situ cross-linked polymerization coupled with a phase inversion technique. The surfaces of these particles are then further modified by grafting amino groups using tetraethylenepentamine, dethylenetriamine, ethylenediamine, or 1,6-hexanediamine for the removal of bilirubin. The particles are characterized by Flourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Batch adsorption experiments are performed to verify the adsorption capability, and the effect of bilirubin initial concentration, bovine serum albumin concentration, and solution ionic strength on the adsorption is also investigated. In addition, both adsorption kinetic and isotherm models are applied to analyze the adsorption process of bilirubin, and a particle column is used to further study the bilirubin removal ability.To prove that the method was a universal portal to prepare functional particles, polysulfone, polystyrene, and poly(vinylidene fluoride) based functional particles were also prepared and used for the removal of bilirubin. This study and the results indicated that the particles had a great potential to be used in hemoperfusion treatment for hyperbilirubinemia.
Graphical Abstract
A comprehensive review of research trends and prospects for interpenetrating polymer networks (IPNs) for desalination and water remediation is presented in this article.
