Cladophora Cellulose: Unique Biopolymer Nanofibrils for Emerging Energy, Environmental, and Life Science Applications

Abstract

Because of its natural abundance, hierarchical fibrous structure, mechanical flexibility, potential for chemical modification, biocompatibility, renewability, and abundance, cellulose is one of the most promising green materials for a bio-based future and sustainable economy. Cellulose derived from wood or bacteria has dominated the industrial cellulose market and has been developed to produce a number of advanced materials for applications in energy storage, environmental, and biotechnology areas. However, Cladophora cellulose (CC) extracted from green algae has unprecedented advantages over those celluloses because of its high crystallinity (>95%), low moisture adsorption capacity, excellent solution processability, high porosity in the mesoporous range, and associated high specific surface area. The unique physical and chemical properties of CC can add new features to and enhance the performance of nanocellulose-based materials, and these attributes have attracted a great deal of research interest over the past decade. This Account summarizes our recent research on the preparation, characterization, functionalization, and versatile applications of CC. Our aim is to provide a comprehensive overview of the uniqueness of CC with respect to material structure, properties, and emerging applications. We discuss the potential of CC in energy storage, environmental science, and life science, with emphasis on applications in which its properties are superior to those of other nanocellulose forms. Specifically, we discuss the production of the first-ever paper battery based on CC. This battery has initiated a rising interest in the development of sustainable paper-based energy storage devices, where cellulose is used as a combined building block and binder for paper electrodes of various types in combination with carbon, conducting polymers, and other electroactive materials. High-activemass and high-mass-loading paper electrodes can be made in which the CC acts as a high-surface-area and porous substrate while a thin layer of electroactive material is coated on individual nanofibrils. We have shown that CC membranes can be used directly as battery separators because of their low moisture content, high mesoporosity, high thermal stability, and good electrolyte wettability. The safety, stability, and capacity of lithium-ion batteries can be enhanced simply by using CC-based separators. Moreover, the high chemical modifiability and adjustable porosity of dried CC papers allow them to be used as advanced membranes for environmental science (water and air purification, pollutant adsorption) and life science (virus isolation, protein recovery, hemodialysis, DNA extraction, bioactive substrates). Finally, we outline some concluding perspectives on the challenges and future directions of CC research with the aim to open up yet unexplored fields of use for this interesting material.

Elastic Aerogels of Cellulose Nanofibers@Metal–Organic Frameworks for Thermal Insulation and Fire Retardancy

“…Cladophora cellulose, a type of natural CNFs extracted from green algae, and Al-MIL-53, an aluminum-based MOF, were used to fabricate CAM nanofibers and aerogels. The extensive mesoporosity and mechanical strength of Cladophora cellulose were expected to result in aerogels with low thermal conductivity and good mechanical properties (e.g., superelasticity, high compressive modulus), respectively [34]. Similarly, the thermal stability and hydrophobicity of Al-MIL-53 were expected to give the aerogels good fire retardancy and moisture resistance, respectively [40][41][42].…”

“…There are several advantages in developing CNF-based composites as thermal insulation materials: (1) The naturally abundant and biodegradable CNFs offer a low-cost, sustainable source of materials for manufacturing; (2) CNFs exhibit intrinsically low thermal conductivity; (3) the nanofibrous structure of CNFs results in large interfacial surface areas which act as phonon barriers with potential to hamper heat conduction; (4) CNFs containing organic functional groups on the surface are ideal substrates for modification or hybridization through surface nanoengineering, offering opportunities to overcome the longstanding problems of moisture sensitivity, flammability, and poor mechanical properties associated with CNF-based materials. We have recently developed a range of hybrid nanocomposites based on CNFs for use in energy and environmental applications [12,[34][35][36][37][38][39]. In this study, we describe the interfacial synthesis and stepwise assembly approach for the design of a hybrid aerogel based on CNFs and an aluminum-based MOF (CNF@ Al-MIL-53; CAM).…”

On the Capacities of Freestanding Vanadium Pentoxide–Carbon Nanotube–Nanocellulose Paper Electrodes for Charge Storage Applications

“…As the latter electrodes are porous, high specific capacities as well as fast charge and discharge rates can be obtained when the thickness of the electroactive coating on the cellulose fibers and CNT fibers is thin enough (e.g., <50 nm). [5,[53][54][55] Recently, this approach was also used in the manufacturing of nanostructured reduced molybdenum trioxide MoO 3-x -CNT-nanocellulose paper electrodes, which were found to show fast charge and discharge rates in supercapacitor applications (e.g., exhibiting the capacities of 30 C g À1 at a current density of 78 A g À1 ). [56] As it is reasonable to assume that this synthesis approach can also be used together with other solution-processable nanostructured materials, this possibility should, consequently, be further investigated.…”

Flexible Freestanding MoO3−x–Carbon Nanotubes–Nanocellulose Paper Electrodes for Charge‐Storage Applications

“…Cellulose is a sustainable and biodegradable material, as well as the most abundant natural polymer, and it can be extracted from wood, algae, and bacteria . Cellulose can be used in many applications, including water purification, fire‐retardants, and paper manufacturing .…”

“…[10,11] Cellulose is as ustainable and biodegradable material, as well as the most abundant natural polymer,a nd it can be extracted fromw ood, algae, and bacteria. [10,[12][13][14][15][16] Cellulose can be used in many applications,i ncludingw ater purification, fire-retardants,a nd paper manufacturing. [13,14] In the last few years, nanocellulose has been used to fabricate paper-basedf lexible electrodes for energy-storagea pplications, owing to its resource abundance,high mechanical flexibility,and excellent solution processability.…”