Three different laundering procedures were prepared and performed with the aim of evaluating the washing performance and dye transfer from the laundering bath onto the textile fabric. The first laundering procedure was performed without added adsorbent for removal of dye and impurities from the laundering bath. Addition of two adsorbents, commercial colour-catcher ribbons or CNF, was the subject of the second and third investigations. The soil removal efficiency and dye uptake were evaluated for all the performed laundering processes. It was found that the use of the surface modified CNF reduced the colouring of white textiles and, thus, re-deposition of dyes and impurities (up to 50.91 %) during the washing process. The laundering in a bath of 20 °C, with addition of CNF adsorbent in the pre-washing phase and detergent CIE A* in the main washing phase, removed a higher amount of stains (5.14%) compared to the laundering without added adsorbent. From the results, it can be concluded that addition of CNF adsorbent ensured efficient washing quality and hindered re-deposition of dyes and impurities during laundering.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 21781270The contribution was presented at inter. conference and exhibition on Nanotechnology. It included different surface modification and functionalization of nano-cellulose, as well as its hybriding with other nano-bioadsorbents (as zeolites and hydroxyapatites), for specific applications in wastewater cleaning and reusing. In this frame, the native or carboxylated cellulose nanofibrils (CNFs) were prepared with in-situ synthesised hydroxyapatite (HAp) and studied for removal of phenoland Co2+ as a model heavy metal ion. On the other hands, the CNFs were surface functionalized with hexamethylenediamine or phosphoric acid groups as an alternative to ion-exchanged and surface modified zeolite-integrated CNFs, to be used in removal of dyes and heavy metal ions. The contaminants removal was investigated by batch adsorption method depending on the pH value, the dosage of adsorbent, initial contaminant concentration and the contact time of adsorption. The adsorbents were further evaluated by applying different kinetics and diffusion model theories to identify the kinetic parameters and to define the diffusion mechanism of adsorption, respectively. The morphology, crystal structure and chemical composition and activity of adsorbents were studied by SEM, XRD, EDX and potentiometric titration analysis, while their physical properties were determined by water contact angle and adsorption swelling kinetic. It was ascertained that HAp precursor leads to a surface modification of CNFs, which increases its activity by forming differently structured, sized and distributed HAp particles, influencing on the phenol and Co2+ adsorption kinetic and capacity as well as reusability. On the other hand, zeolite surface modification, content, distribution and globule-like structures in CNF matrix influencing on dye (electrostatic, physical, and hydrophobic) adsorption mechanism and removal capacity.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 21925398The contribution was presented at world conference of TAPPI's NanoDivision (a leading technical association for the use and production of renewable and sustainable nanomaterials, focusing on nano cellulose). It demonstrated a processing of new type of nanocellulose-based self-standing films acting as adsorbents or filters by integration of cellulose nanofibrils with minerals, and their relevance for removal of different ionic pollutants and Ca/Mg cations (water softening).
B.03 Paper at an international scientific conference
COBISS.SI-ID: 20384278The contribution was presented at 4th international conference on Nanostructured materials and nanocomposites (ICNM 2017) in Kottayam, India. It demonstrated a processing of new type of nanocellulose-based composite adsorbents and filters by integration of cellulose nanofibrils with zeolites or hydroxyapatite, and their relevance for removal of different pollutants as dyes, phenol and cobalt, as well as carbonates.
B.04 Guest lecture
COBISS.SI-ID: 20274966The contribution was presented at the 8th Monolith Summer School & Symposium, being organised by project partner BIA Separations between 15th-20th June 2018 in Portorož, Slovenia. The cellulose and its variants are one of the most common chromatographic supports for purifying biological molecules because of its biocompatibility, stability and easy modification with varied ligands. However, the preparation of cellulose-based chromatographic support, enabling preferentially convective mass transport, is a procedure which still based mainly on double emulsification in ionic liquids followed by chemical cross-linking or surface modifications to be converted into an anion exchanger. In this research, we provided a green approach to fabricate the cellulose membranes with macro-pores by using carboxymethyl cellulose (CMC) as weak cation-exchanging polymer and cellulose nanofibrils (CNFs) as stabilizing and structural filler, in which the macro-pores were generated by variation of their mass weigh ratio and using a freeze-casting process, while their stability was obtained by esterification of available hydroxyl groups using citric acid mediated chemistry performed in situ during the fabrication. The membrane’s charge and porosity affecting lysozyme (Lys) binding capacity and transport was evaluated by potentiometric titration and SEM imaging. Prepared membranes were packed in a chromatographic housing and tested for model protein (Lys) binding and elution at different flow rates. Due to very open structure the permeability of the membranes is very high and Lys recovery above 95% was achieved regardless the membrane tested. But Lys was partially retained by the column, what was additionally negatively influenced by flow rate increase. The membrane binding capacity, calculated from Lys elution, was in the range between 0.3 and 0.7 mg of Lys per mg of dry membrane, which is a promising result.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 21629206