Preparation and formation mechanism study of the long-term stable foamed sodium carboxymethyl cellulose loaded material
Abstract
A foamed sodium carboxymethyl cellulose (CMC) material was prepared under nitric acid conditions. Unlike traditional CMC materials, this foaming method is straightforward and does not require additional foaming agents. Due to its high stability and load capacity, the foam can realize long-term quantitative storage and load a variety of metal ions, therefore, it has broad application prospects in the field of loaded materials for metal ions. In this work, infrared spectroscopy and nuclear magnetic resonance (NMR) spectroscopy were used to explore the interaction between CMC and nitric acid in the foam under these conditions. The mechanism of foam formation was reasonably explained. Infrared spectra reveal the hydrolysis of the cellulose framework by nitric acid. Based on experimental observations during preparation and NMR analysis, it is explained that nitric acid activates glucose units’ C1 (No.1 carbon in glucose unit) in CMC, leading to the formation of reducible terminal groups. Additionally, as the concentration of nitric acid increases during solution evaporation, a fraction of these reducible terminal groups undergo oxidation by nitric acid, resulting in gas production and subsequent expansion of the system, ultimately forming a foamed structure upon complete drying.
https://doi.org/10.5061/dryad.vmcvdnd28
Description of the data and file structure
500 M Superconducting Nuclear Magnetic Resonance Spectrometer was used to collect the H/C-NMR data.
Fourier Transform Infrared Spectrometer was used to collect the IR data.
Files and variables
File: DATA.zip
Description: The file IR data in this compressed archive include IR spectra of the raw material and different foams in different acidity (named as raw material.SPA, 2M HNO3.SPA, 3M HNO3.SPA, 4M HNO3.SPA, raw material.CSV, 2M HNO3.CSV, 3M HNO3.CSV, and 4M HNO3.CSV ).
The file C-NMR data in this compressed archive include 13C-NMR spectra of the raw material and different foams in different acidity (named as raw material, 2M HNO3, 3M HNO3, and 4M HNO3), only the files named as fid in the subfolders show the C-NMR spectra. Other files are files that are necessary for the software to run or files that record fid file details.
The file H-NMR data in this compressed archive include 1H-NMR spectra of the raw material and different foams in different acidity (named as raw material, 2M HNO3, 3M HNO,3 and 4M HNO3), only the files named as fid in the subfolders show the H-NMR spectra. Other files are files that are necessary for the software to run or files that record fid file details.
Code/software
The IR data files named raw material.SPA, 2M HNO3.SPA, 3M HNO3.SPA, and 4M HNO3.SPA should be opened using the OMNIC software. If OMNIC is not available, the corresponding CSV files (raw material.CSV, 2M HNO3.CSV, 3M HNO3.CSV, and 4M HNO3.CSV) can also be used to access IR data. These CSV files are compatible with Origin 2019b (and other versions) and can also be viewed in Microsoft Excel, as they contain the same valid information as the SPA files.
For C-NMR data, the files named fid within the subfolders of the C-NMR data directory should be opened using MestReNova (version 14.0.0-23239 or later) to obtain the C-NMR spectra. This software is freely available for processing NMR data.
Similarly, for H-NMR data, the fid files within the subfolders of the H-NMR data directory should also be opened using MestReNova (version 14.0.0-23239 or later) to obtain the H-NMR spectra.
Access information
Other publicly accessible locations of the data:
- The standard infrared spectrum of sodium carboxymethyl cellulose (https://sdbs.db.aist.go.jp/CompoundLanding.aspx?sdbsno=2754)
IR data of CMC raw material and foams were collected with the KBr pellet method by Fourier Transform Infrared Spectrometer, Nicolet iS50, Thermo Fisher Scientific Inc. it was processed by the software OMNIC.
NMR data of CMC raw materials and foams were collected by a 500 M Superconducting Nuclear Magnetic Resonance Spectrometer, Avance Ⅲ 500, Brulcer CO, and processed using the software MestReNova.
The standard infrared spectrum of CMC was provided in the database of the National Institute of Advanced Industrial Science and Technology (AIST), an open compound spectral database, without processing.(URL: https://sdbs.db.aist.go.jp/CompoundLanding.aspx?sdbsno=2754)