Synthesis and Characterization of Cellulose Acetate Membranes with Self-Indicating Properties by Changing the Membrane Surface Color for Separation of Gd(III)

Abstract

This study presents a new, revolutionary, and easy method for evaluating the separation process through a membrane that is based on changing the color of the membrane surface during the separation process. For this purpose, a cellulose acetate membrane surface was modified in several steps: initially with amino propyl triethoxysilane, followed by glutaraldehyde reaction and calmagite immobilization. Calmagite was chosen for its dual role as a molecule that will complex and retain Gd(III) and also as an indicator for Gd(III). At the contact with the membrane surface, calmagite will actively complex and retain Gd(III), and it will change the color of the membrane surface during the complexation process, showing that the separation occurred. The synthesized materials were characterized by Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA-DTA), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, demonstrating the synthesis of membrane material with self-indicating properties. In addition, in the separation of the Gd(III) process, in which a solution of gadolinium nitrate was used as a source and as a moderator in nuclear reactors, the membrane changed its color from blue to pink. The membrane performances were tested by Induced Coupled Plasma–Mass Spectrometry (ICP-MS) analyses showing a separation process efficiency of 86% relative to the initial feed solution.

One-Step Synthesis of Eu3+-Modified Cellulose Acetate Film and Light Conversion Mechanism

“…The C1s and O1s chemical bonds in the pure CA film, CA-Eu, and CA–Eu–Tb light conversion films were analyzed by peak fitting method. Figure 2 b is the C1s spectrum of CA, containing three peaks positioned at 284.8, 286.774, and 289.002 eV, which were respectively assigned to C–C or C–H in the molecular chain skeleton, C–OH and C–O–C bond in the pyranose ring, and O=C–O in the acetyl group, respectively [ 19 , 20 , 21 ]. As shown in Figure 2 c,d, the spectral shapes changed and the O–C=O bond of CA–Eu and CA–Eu–Tb light-converting films had moved 0.163 eV and 0.269 eV to the lower binding energy position compared with CA film, respectively.…”

Activated Carbon Loaded Mixed Matrix Membranes Extracted from Oil Palm Empty Fruit Bunches for Vehicle Exhaust Gas Adsorbers

“…Functional group analysis was carried out to determine the compounds after the acetylation reaction by identifying the typical absorbance values and functional groups contained in the CA by using FTIR 21) . Fig.…”

Photocatalytic Degradation of Methylene Blue Using Polymeric Membranes Based on Cellulose Acetate Impregnated with ZnO Nanostructures

“…The application of nanocomposite (hybrid) materials as catalysts or adsorbents to remove toxic substances from wastewater has received great attention in the last decade. The adsorbents may be of mineral, organic, or biological origin, such as clay, zeolites, activated carbons, silica beads, polymeric materials, and metal oxides [ 17 , 18 , 19 , 20 , 21 , 22 ].…”

“…Among metal oxides, zinc oxide (ZnO) in its nanostructured form is a favorable semiconducting oxide for application as a nanocomposite polymeric material due to its large variety of low dimensional nanostructures, effective adsorption, high surface reactivity, adsorption capacity, and destructive sorbent ion capacity [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. ZnO nanostructures (such as nanoparticles, nanowires, nanoflowers, and nanosheets) as multifunctional inorganic nanomaterials have been widely applied in the polymeric membrane modification process [ 24 , 25 , 26 , 27 , 28 ].…”