RESUMEN
The effective purification of aqueous solutions of methylene blue dye was tested using polymer inclusion membranes (PIMs) that contained cellulose triacetate (CTA) as a polymer base, o-nitrophenyl octyl ether (o-NPOE) as a plasticizer, and meso-tetra methyl tetrakis-[methyl-2-(4-acetlphenoxy)] calix[4]pyrrole (KP) as a carrier. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy were used to define the microstructure and surface of PIMs. Experimental results showed that, with an increased concentration of methylene blue in an aqueous solution, the removal percentage also increased. Further observation showed that the flux increased with the rise in the source phase pH values from 3 to 10. The carrier and plasticizer content in the membrane significantly influenced the membrane's transport properties. The optimal composition of the membrane in percent by weight for KP was 74% plasticizer; 18% support, and 8% carrier. The maximum MB removal (93.10%) was achieved at 0.10 M HCl solution as the receiving phase. It was shown that the membrane with optimal composition showed good reusability and enabled the easy and spontaneous separation of methylene blue from aqueous solutions.
RESUMEN
Production wastewater has evolved with dye and printing technology to become one of the major sources of soil and water contamination. The majority of dyes are carcinogenic, teratogenic, and mutagenic compounds. As a result, dealing with the dye in the wastewater is a critical issue. Insoluble polymers of ß-cyclodextrin (ß-CD), an inexpensive, sustainably produced macrocycle of glucose, have potential to remove dyes from water/wastewater via sorption due to formation of well-defined host-guest complexes. A novel polymeric sorbent based on cyclodextrin was successfully synthesized in a one-step reaction with few reagents. The polymer is characterized by multifunctionality and cross-linked network structure. The sorption studies aimed at the removal of methylene blue (MB) from aqueous solutions. The dominant model was Langmuir isotherm which indicated a sorption capacity of 96.15 mg/g. The rapid removal has already been obtained after 1 min, around 84 % of efficiency. The molecular mechanism of MB sorption by poly(ß-CD-BPDA) network is found mostly on the electrostatic interactions and partially on the inclusion of complexation inside supramolecular pores based on cyclodextrins' cavities, hydrogen bonding and slightly π-stacking. The presented polymer seems to be a promising sorbent for the removal of hazardous organic pollutants from water/wastewater.
RESUMEN
Polymer membranes with immobilized ligands are encouraging alternatives for the removal of toxic metal ions from aquatic waste streams, including industrial wastewater, in view of their high selectivity, stability, removal efficacy and low energy demands. In this study, polymer inclusion membranes (PIMs) based on cellulose triacetate, with a calix[4]pyrrole derivative as an ion carrier, were tested for their capability to dispose mercury (Hg(II)) ions from industrial wastewater. The impacts were assessed relative to carrier content, the quantity of plasticizer in the membrane, the hydrocholoric acid concentration in the source phase, and the character of the receiving phase on the performance of Hg(II) elimination. Optimally designed PIMs could be an interesting option for the industrial wastewater treatment due to the high removal efficiency of Hg(II) and great repeatability.
RESUMEN
The aim of this paper is to investigate the interactions between polysaccharides with different electrical charges (anionic and neutral starches) and proteins and fats in food ingredients. Another objective is to understand the mechanisms of these systems and the interdependence between their properties and intermolecular interactions. At present, there are not many studies on ternary blends composed of natural food polymers: polysaccharides of different electrical charge (anionic and neutral starches), proteins and lipids. Additionally, there are no reports concerning what type of interactions between polysaccharide, proteins and lipids exist simultaneously when the components are mixed in different orders. This paper intends to fill this gap. It also presents the application of natural biopolymers in the food and non-food industries.
RESUMEN
Cyclodextrins (CDs) are a family of macrocyclic oligosaccharides mostly composed of six, seven, or eight α-D-glucopyranose units with α-1,4-glycosidic bonds to form toroidal structures. The CDs possess a hydrophilic exterior and hydrophobic interior with the ability to form an inclusion complex, especially with hydrophobic molecules. However, most existing studies are about conjugation CDs with peptide/protein focusing on the formation of new systems. The CD-peptide/protein can possess new abilities; particularly, the cavity can be applied in modulation properties of more complexed proteins. Most studies are focused on drug delivery, such as targeted delivery in cell-penetrating peptides or co-delivery. The co-delivery is based mostly on polylysine systems; on the other hand, the CD-peptide allows us to understand biomolecular mechanisms such as fibryllation or stem cell behaviour. Moreover, the CD-proteins are more complexed systems with a focus on targeted therapy; these conjugates might be controllable with various properties due to changes in their stability. Finally, the studies of CD-peptide/protein are promising in biomedical application and provide new possibilities for the conjugation of simple molecules to biomolecules.
RESUMEN
New water soluble amino ß-cyclodextrin-based polymer was synthesized by reaction between amino cyclodextrin derivatives and pyromellitic anhydride. This experiment presents amino derivatives, which were synthesized by attaching amino groups to ß-cyclodextrins (ß-CDs) used mono-6-azido-6-deoxy-ß-cyclodextrin (ß-CD-N3) and triphenylphosphine (Ph3P) in anhydrous N,N-dimethylformamide (DMF). An amino blocking reaction was conducted. The obtained polymer was purified by ultrafiltration. In addition, an attempt was made to create nanospheres by encapsulating the polymer with chitosan (CT) in an acidic condition. For the first time, nanospheres were obtained in the reaction between an amino ß-cyclodextrin polymer and chitosan. Scanning electron microscopy (SEM). 1H NMR and ESI-MS methods for confirmation of reaction product and for structural characterization were employed. The differential scanning calorimetry (DSC) studies of polymers were also carried out.