Fast sensing ammonia at room temperature with proline ionic liquid incorporated cellulose acetate membranes

High efficient removal of lead(II) and cadmium(II) ions from multi-component aqueous solutions using polyacrylic acid acrylonitrile talc nanocomposite

This study is interested in the removal of Pb(II), Cd(II), Co(II), Zn(II), and Sr(II) onto polyacrylic acid acrylonitrile talc P(AA-AN)-talc nanocomposite. P(AA-AN)-talc was fabricated using γ-irradiation-initiated polymerization at 50 kGy. Different analytical tools were used to investigate the functional groups, morphology, particle size, and structure of this composite. The ability of P(AA-AN)-talc to capture (Pb²⁺, Cd²⁺, Co²⁺, Zn²⁺, and Sr²⁺) as multi-component aqueous solutions was performed by a batch method. Saturation capacity and the effect of (agitating time, pH, initial metal concentrations, and temperature) were investigated. The distribution coefficients at different pHs have order: Pb²⁺  > Cd²⁺  > Co²⁺  > Zn²⁺  > Sr²⁺. The saturation capacity decreases by increasing heating temperatures. Reaction kinetic obeys the pseudo-second-order model. Sorption isotherms are more relevant to a Langmuir isotherm, and the monolayer sorption capacity is closed to saturation capacity. Thermodynamic parameters (∆G˚, ∆H˚, and ∆S˚) were endothermic and spontaneous. P(AA-AN)-talc is used for loading and recovery of studied cations in the column system. The study confirms that P(AA-AN)-talc is a promised composite for the sorption of the studied ions from aqueous solutions and should be considered as potential material for decontaminating these ions.

Cellulose acetate in fabrication of polymeric membranes: A review

Developing biodegradable polymers to fabricate filtration membranes is one of the main challenges of membrane science and technology. Cellulose acetate (CA) membranes, due to their excellent film-forming property, high chemical and mechanical stability, high hydrophilicity, eco-friendly, and suitable cost, are extensively used in water and wastewater treatment, gas separation, and energy generation purposes. The CA is one of the first materials used to fabricate filtration membranes. However, in the last decade, the possibility of modification of CA to improve permeability and stability has attracted the researcher's attention again. This review is focused on the properties of cellulose derivatives and especially CA membranes in the fabrication of polymeric separation membranes in various applications such as filtration, gas separation, adsorption, and ion exchange membranes. Firstly, a brief introduction of CA properties and used molecular weights in the fabrication of membranes will be presented. After that, different configurations of CA membranes will be outlined, and the performance of CA membranes in several applications and configurations as the main polymer and as an additive in the fabrication of other polymer-based membranes will be discussed.

Preparation, characterization, and applications of polyacrylonitrile/ball clay nanocomposite synthesized by gamma radiation

Elimination of hazardous metals is of extreme worry for their toxicity at trace levels and accumulation in the biosystem. Polyacrylonitrile ball clay nanocomposite was prepared by gamma irradiation at 20 kGy. Different analytical tools were applied to prove morphology, functional groups, and chemical structure for prepared composite; SEM, TEM, IR, XRD, and XRF. From TEM and XRD data expose the studied composite has nanoscale and crystalline. The adsorption of Cs⁺, Co²⁺ and Fe³⁺ onto studied material took place after 24 h. Second order was preceded by the kinetic system. The capacity and effect of pH on k_d reflect selectivity sequence; Co²⁺  > Fe³⁺  >  > Cs⁺. Both Freundlich and Langmuir are applicable for investigated material. Finally, PAN/BC nanocomposite is suitable for the column technique.

Rice Husk-Derived Cellulose Nanofibers: A Potential Sensor for Water-Soluble Gases

Cellulose and its derivatives have evoked much attention in sensor technology as host-matrices for conducting materials because of their versatility, renewability, and biocompatibility. However, only a few studies have dealt with the potential utilization of cellulose as a sensing material without a composite structure. In this study, cellulose nanofibers (CNF) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOCNF) extracted from rice husks by using ultrasonic-assisted methods are introduced as a potential gas sensing material with highly sensitive performance. To fabricate nanocellulose-based films, CNF, TOCNF, and TOCNF with glycerol (TOCNF/G) were dispersed in water and applied on polyimide substrate with digital electrodes to form self-standing thin films by a drop-casting method. A transparent coating layer on the surface of the plate after drying is used for the detection of water-soluble gases such as acetone, ammonia, methane, and hydrogen sulfide gases at room temperature at 52% relative humidity. The sensor prototypes exhibited high sensitivity, and the detection limit was between 1 ppm and 5 ppm, with less than 10 min response and recovery time. The results indicate that both the CNF- and the TOCNF-coated sensors show good sensitivity toward ammonia and acetone, compared to other gases. A TOCNF/G-coated sensor exhibited minimum time in regard to response/recovery time, compared to a CNF-coated sensor. In this study, nanocellulose-based sensors were successfully fabricated using a low-cost process and a bio-based platform. They showed good sensitivity for the detection of various gases under ambient conditions. Therefore, our study results should further propel in-depth research regarding various applications of cellulose-based sensors in the future.

Recent advances in cellulose-based membranes for their sensing applications

ABSTRACT

In recent years, sensing applications have played a very important role in various fields. As a novel natural material, cellulose-based membranes with many merits can be served as all kinds of sensors. This review summarizes the recent progress of cellulose membranes as sensors, mainly focusing on their preparation processes and sensing properties. In addition, the opportunities and challenges of cellulose membrane-based sensors are also prospected. This review provides some references for the design of cellulose membrane materials for sensing applications in the future.