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This work reports on a simple and environmentally benign route to prepare freestanding magnetic films based on cellulose derivatives through the combination of cobalt ferrite (CoFe 2 O 4 ) nanoparticles with methyl cellulose (MC), hydroxypropyl cellulose (HPC), and sodium carboxymethyl cellulose (NaCMC). Nanoparticles are able to "shield" hydrogen bonding interactions between polysaccharide chains and lower the viscosity of water-dissolved MC, HPC, and NaCMC, allowing an easy film fabrication. Crack-free films with homogeneously dispersed nanoparticles having concentrations up to 50 wt % are fabricated by mechanical agitation followed by doctor blade casting. All of the nanocomposite films keep a substantial level of flexibility with elongation at break exceeding 5%. Halpin-Tsai equations serve to provide further insights on the character of matrix-CoFe 2 O 4 interfaces. Magnetization saturation increases almost linearly with cobalt ferrite concentration up to a maximum value of ∼24-27 emu g -1 for nanocomposites containing 50 wt % of nanoparticles. The dielectric response of the films demonstrates a strong dependence on both the functional groups attached to the main cellulose chain and the ferrite nanoparticle content. The renewable character of the hosting matrices, together with the fabrication methods that solely uses water as a solvent, the decrease of the viscosity with the inclusion of fillers, particularly suitable for printable materials, and the resulting magnetic performance provide novel avenues for the replacement of traditional magnetoactive composites based on petroleum-derived polymers and avoiding the use of toxic solvents.

Novel core-shell superparamagnetic nanofluids composed of magnetic iron oxide (Fe 3 O 4 , MION) and cobalt-doped (Co x Fe 3-x O 4 , Co-MION) nanoparticles functionalized with carboxymethyl cellulose (CMC) ligands were designed and produced via green colloidal aqueous process. The effect of the degree of substitution (DS = 0.7 and 1.2) and molecular mass (M w ) of CMC and cobalt doping concentration on the physicochemical and magnetic properties of these nanoconjugates were comprehensively investigated using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction, transmission electron microscopy (TEM) with selected area electron diffraction, X-ray fluorescence, dynamic light scattering (DLS), zeta potential (ZP) analysis, vibrating sample magnetometry (VSM) and electron paramagnetic resonance spectroscopy (EPR). The results demonstrated the effect of concentration of carboxylate groups and M w of CMC on the hydrodynamic dimension, zeta potential, and generated heat by magnetic hyperthermia of MION nanoconjugates. Co-doping of MION showed significant alteration of the electrostatic balance of charges of the nanoconjugates interpreted as effect of surface interactions. Moreover, the VSM and EPR results proved the superparamagnetic properties of these nanocolloids, which were affected by the presence of CMC and Co-doping of iron oxide nanoparticles. These magnetic nanohybrids behaved as nanoheaters for killing brain cancer cells in vitro with prospective future applications in oncology and nanomedicine., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Nowadays the development of natural biomaterials as promising building polymers for flexible, biodegradable, biocompatible and environmentally friendly electronic devices is of great interest. As the most common natural polymers, cellulose and its derivatives have the potential to be applied in the devices owing to the easy processing, nontoxicity and biodegradability. Here, write-once-read-many-times resistive switching devices based on biodegradable carboxymethyl cellulose-graphene oxide (CMC-GO) nanocomposite are demonstrated for the first time. The hybridization sites formed by the gelation of CMC and GO molecules contribute to the excellent memory behaviors. When compared with devices base on pure GO and CMC, the device with the Al/CMC-GO/Al/SiO 2 structure exhibits brilliant write-once-read-many-times (WORM) switching characteristics such as high ON/OFF current ratio of ˜10 5 , low switching voltage of 2.22 V, excellent stability and durability. What's more, the device shows high flexibility and good resistive switching behaviors even with soft PET substrate (Al/CMC-GO/Al/PET structure). This newly designed cellulose-graphene oxide-based polymer nanocomposites are quite cheap and easy processed for large scale manufacturing of memory devices and can further contribute to future biodegradable data storage applications such as portable stretchable displays, wearable electronics and electronic skins in the coming age of artificial intelligence., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Significant efforts have been made to develop composite membranes with high adsorption efficiencies for water treatment. In this study, a carboxymethyl cellulose-graft-poly(acrylic acid) membrane was synthesized in the presence of silica gel, which was used as an inorganic support. Then, different amounts of bentonite were introduced to the carboxymethyl cellulose (CMC) grafted networks as a multifunctional crosslinker, and nanocomposite membranes were prepared. The nanocomposite membranes were characterized using Fourier transform infrared spectroscopy, and scanning electron microscopy, which revealed their compositions and surface morphologies. The novel synthesized nanocomposite membranes were utilized as adsorbents for the removal of crystal violet (CV) and cadmium (Cd (II)) ions, which were selected as representatives of a dye and a heavy metal, respectively. We explored the effects of various parameters, such as time, pH, temperature, initial concentration of adsorbate solution and amount of adsorbent, on membrane adsorption capacity. Furthermore, the kinetic, adsorption isotherm models and thermodynamic were employed for the description of adsorption processes. The maximum adsorption capacities of membranes for CV and Cd (II) ions were found to be 546 and 781 mg g(-1), respectively. The adsorption of adsorbate ions by all types of nanocomposite membranes followed pseudo-second-order kinetic model and was best fit with the Freundlich adsorption isotherm. The results indicated that the synthesized nanocomposite membrane is an efficient adsorbent for the removal of cationic dye and metal contaminants from aqueous solution during water treatment., (Copyright © 2015 Elsevier Ltd. All rights reserved.)