Ethyl cellulose composite membranes containing a 2D material (MoS2) and helical carbon nanotubes for efficient solar steam generation and desalination

Fabrication of advanced cellulose-based devices for solar desalination: A review

Materials derived from cellulose have attracted considerable attention as affordable substrates for solar desalination, contributing to the solution of the worldwide water crisis. These substances allow for exact control of structural features and improve light absorption in photothermal processes, promoting specific interactions between light scattering and reflection within their porous structure. Moreover, cellulose can be readily transformed into nano- and microporous forms, which enhances water transportation due to its inherent three-dimensional properties. This review examines the design and utilization of cellulose-based solar evaporators for desalination purposes. With benefits such as biocompatibility, environmental friendliness, economic viability, renewable nature, sustainability, and versatility for diverse designs, cellulose-derived materials are set to play a vital role in addressing global water issues.

Floatable and magnetic MoS2/NiFe2O4/chitosan nanocomposite integrated melamine sponges with hybrid photothermal and photocatalytic enhancement for pollutant removal

Magnetic chitosan-based materials with good adsorption-photocatalysis and magnetic properties have great prospect in wastewater treatment. In this paper, a floating magnetic molybdenum disulfide/NiFe2O4/chitosan integrated melamine sponges (m-MoS2/CS@MS) was fabricated using chitosan as absorbent and adhesive, MoS2 and NiFe2O4 as photocatalysts, and melamine sponge as support material. The m-MoS2/CS@MS has a rich light-water-air-material interaction interface and can float on the water surface. The light absorbance of m-MoS2/CS@MS had dramatically increased by 55.77 % with the introduction of MoS2 and NiFe2O4 nanoparticles. The m-MoS2/CS@MS can effectively remove Congo red dye at pH = 2-10 under different coexisting inorganic salts (Cl-, SO42-) and water matrices (ultrapure water, tap water, Lake water, and mineral water). The m-MoS2/CS@MS had excellent photocatalytic degradation ability, reaching a degradation rate of 98.88 % under simulated solar light irradiation. Furthermore, the m-MoS2/CS@MS composite exhibited excellent stability, convenient magnetic recycling performance, reusability and its suitability for dye wastewater treatment under different conditions. This research provided a new insight into the practical application of sustainable and clean chitosan-based materials.

Electrospun composite membranes of ethyl cellulose and MXene (Ti3C2Tx): Biocompatible platforms for enhanced drug delivery and antibacterial wound healing

Ethyl cellulose (EC), a degradable cellulose derivative, served as a primary component in membranes fabricated by electrospinning for in vitro drug delivery applications. An effective strategy to enhance drug release was incorporating high-surface-area nanomaterials into polymeric drug carriers, which facilitated drug attachment to both the polymer matrix and additive surfaces, promoting release. MXene (Ti3C2Tx) demonstrated promising potential in improving tensile mechanical properties, antibacterial activity, and curcumin (Cur) release performance of EC membrane. Compared to Cur-loaded EC/MXene membranes, the toughness of Cur-loaded EC-based carriers significantly increased by 53.58 %, reaching 3.821 kJ/m3. This composite membrane exhibited exceptional antibacterial efficacy, notably reducing Staphylococcus aureus colonies by 52.4 × 107 CFU/mL after 168 h, through the dilution spread plate method. Using MTT assay, the composite membrane demonstrated biocompatibility, as evidenced by >70 % viability of mouse fibroblast L929 cells with observable cell attachment after 168 h. Importantly, the EC/MXene membrane achieved a Cur release amount of 69.82 % compared to 7.11 % from Cur-loaded EC membranes within 168 h, representing a 62.71 % enhancement in Cur release. The EC/MXene composite membrane is a promising drug delivery candidate, particularly for Cur, by utilizing the sustainability of EC as the primary drug carrier component.

A MAX phase (Ti3AlC2) as a performance enhancer for poly(lactic acid) electrospun membranes in steam generation and solar desalination

Clean water and sanitation issues motivate researchers to develop water evaporators for freshwater generation. The composite membrane evaporator was electrospun herein based on poly(lactic acid) (PLA) and Ti3AlC2 MAX phase as a property enhancer. As a precursor for the MXenes synthesis, the MAX phase has never been explored with PLA for water evaporator potential. Alternative use of the MAX phase can reduce the production cost arising from chemical synthesis. This work explored the potential of the MAX phase as an additive to enhance PLA membrane performance for steam generation and desalination applications. Under the infrared irradiation (∼1.0 kW/m2), the mechanically-improved PLA/MAX phase membrane showed an enhanced water evaporation rate of 1.70 kg/m2 h (93.93 % efficiency), with an approximately 52 % rate increment relative to the PLA membrane. Based on the artificial seawater (3.5 % w/w), the membrane exhibited an evaporation rate of 1.60 kg/m2 h (87.57 % efficiency). The membrane showed self-floating ability at the air-water interface, excellent thermal stability over the entire operating temperatures, and reusability after repeated cycles. Moreover, the generated freshwater contained exceptionally low cations concentrations, as low as those in potable water. The developed composite membrane also had proved its potential for solar desalination in the water generation field.

An ethyl cellulose novel biodegradable flexible substrate material for sustainable screen-printing

We introduce an innovative solution to reduce plastic dependence in flexible electronics: a biodegradable, water-resistant, and flexible cellulose-based substrate for crafting electrochemical printed platforms. This sustainable material based on ethyl cellulose (EC) serves as an eco-friendly alternative to PET in screen printing, boasting superior water resistance compared to other biodegradable options. Our study evaluates the performance of carbon-based screen-printed electrodes (SPEs) fabricated on conventional PET, recycled PET (r-PET), and (EC)-based materials. Electrochemical characterization reveals that EC-SPEs exhibit comparable analytical performance to both P-SPEs and rP-SPEs, as evidenced by similar limits of detection (LOD), limits of quantification (LOQ), and reproducibility values for all the analytes tested (ferro-ferricyanide, hexaammineruthenium chloride, uric acid, and hydroquinone). This finding underscores the potential of our cellulose-based substrate to match the performance of conventional PET-based electrodes. Moreover, the scalability and low-energy requirements of our fabrication process highlight the potential of this material to revolutionize eco-conscious manufacturing. By offering a sustainable alternative without compromising performance, our cellulose-based substrate paves the way for greener practices in flexible electronics production.

Distribution-according-to-work: Enhancing solar vapor generation of photothermal sponge by using cellulose-based water storage platform

Interfacial solar vapor generation (ISVG) has shown extraordinary promise in achieving high-efficiency water purification. However, the rapid water supply often leads to excessive water in the solar absorber, resulting in undesired heat loss and a decrease in evaporation rate. To tackle this issue, we developed a bio-based solar evaporator comprising cellulose-based water retention resin (CRR) and straw-derived photothermal sponge. CRR serves as an effective water storage platform with a high binding capacity for water molecules, preventing water from entering the absorber and reducing the water evaporation enthalpy. The water management of CRR confines the solar-to-vapor conversion to the interface between CRR and the photothermal sponge, thereby eliminating the adverse effects of excess water. Additionally, the ISVG process operates based on the principle of Distribution-according-to-work, meaning that the quantity of generated vapor depends on the evolution of the sponge structure. Optimal sponge configuration enables evaporation rates of 2.28 and 1.53 kg/m2/h under solar irradiation of 1.0 and 0.5 kW/m2, respectively. Additionally, the obtained evaporator is capable of producing 7.1 kg/m2/day of freshwater in outdoor experiment. This report proposes a novel approach to designing an ISVG device that incorporates effective water management strategy for achieving high-efficiency water purification in real-world scenarios.

Enhanced mechanical properties and biocompatibility of bacterial cellulose composite films with inclusion of 2D MoS2 and helical carbon nanotubes for use as antimicrobial drug carriers

Bacterial cellulose (BC) is a biomaterial being investigated for a range of applications. Herein, BC films derived from nata de coco pieces are reinforced by two-dimensional molybdenum disulfide (MoS2) and helical carbon nanotubes (HCNTs) to enhance their tensile mechanical properties, and the biocompatibility of the BC composite films is demonstrated. A simple preparation is presented using a kitchen blender to disperse and blend the BC fibers and additives in a common fabrication medium, followed by vacuum filtration. The mechanical properties of the BC/MoS2/HCNTs composite films are enhanced due to the synergistic effect of MoS2 and HCNTs embedded in the BC films. The MoS2/HCNTs binary additive (1 phr) is capable of increasing the strength and Young's modulus by 148 % and 333 %, respectively, relative to the BC films. The cell cytotoxicity of the BC/MoS2/HCNTs films was assessed using an MTT assay. The composite films are biocompatible with a cell viability of L929 fibroblast cells >70 %, coupled with observations of direct cell attachment on the films. The composite films also exhibited good performance in absorbing and releasing gentamicin antibiotics to inhibit the growth of Escherichia coli and Staphylococcus aureus. The BC/MoS2/HCNTs films are thus potential BC-based candidates as biocompatible robust antibiotic carriers.