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Man‐made continuous fibers play an essential role in society today. With the increase in global sustainability challenges, there is a broad spectrum of societal needs where the development of advanced biobased fibers could provide means to address the challenges. Biobased regenerated fibers, produced from dissolved cellulose are widely used today for clothes, upholstery, and linens. With new developments in the area of advanced biobased fibers, it would be possible to compete with high‐performance synthetic fibers such as glass fibers and carbon fibers as well as to provide unique functionalities. One possible development is to fabricate fibers by spinning filaments from nanocellulose, Nature's nanoscale high‐performance building block, which will require detailed insights into nanoscale assembly mechanisms during spinning, as well as knowledge regarding possible functionalization. If successful, this could result in a new class of man‐made biobased fibers. This work aims to identify the progress made in the field of spinning of nanocellulose filaments, as well as outline necessary steps for efficient fabrication of such nanocellulose‐based filaments with controlled and predictable properties.

 

Membrane technology remains the most energy‐efficient process for removing contaminants (micrometer‐size particles to angstrom‐size hydrated ions) from water. However, the current membrane technology, involving relatively expensive synthetic materials, is often nonsustainable for the poorest communities in the society. In this article, perspectives are provided on the emerging nanocellulose‐enabled membrane technology based on nanoscale cellulose fibers that can be extracted from almost any biomass. It is conceivable that nanocellulose membranes developed from inexpensive, abundant, and sustainable resources (such as agriculture residues and underutilized biomass waste) can lower the cost of membrane separation, as these membranes offer the ability to remove a range of pollutants in one step, via size exclusion and/or adsorption. The nanocellulose‐enabled membrane technology not only may be suitable for tackling global drinking water challenges, but it can also provide a new low‐cost platform for various pressure‐driven filtration techniques, such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. Some relevant parameters that can control the filtration performance of nanocellulose‐enabled membranes are comprehensively discussed. A short review of the current state of development for nanocellulose membranes is also provided.

 

Fibrous materials serve as an intriguing class of 3D materials to meet the growing demands for flexible, foldable, biocompatible, biodegradable, disposable, inexpensive, and wearable sensors and the rising desires for higher sensitivity, greater miniaturization, lower cost, and better wearability. The use of such materials for the creation of a fibrous sensor substrate that interfaces with a sensing film in 3D with the transducing electronics is however difficult by conventional photolithographic methods. Here, a highly effective pathway featuring surface‐mediated interconnection (SMI) of metal nanoclusters (NCs) and nanoparticles (NPs) in fibrous materials at ambient conditions is demonstrated for fabricating fibrous sensor substrates or platforms. Bimodally distributed gold–copper alloy NCs and NPs are used as a model system to demonstrate the semiconductive‐to‐metallic conductivity transition, quantized capacitive charging, and anisotropic conductivity characteristics. Upon coupling SMI of NCs/NPs as electrically conductive microelectrodes and surface‐mediated assembly (SMA) of the NCs/NPs as chemically sensitive interfaces, the resulting fibrous chemiresistors function as sensitive and selective sensors for gaseous and vaporous analytes. This new SMI–SMA strategy has significant implications for manufacturing high‐performance fibrous platforms to meet the growing demands of the advanced multifunctional sensors and biosensors.

 

In this study, granulated activated charcoal (GAC) and bio charcoal (BC) is used as a filler in P3 biosand bag filter to study their filtration performance against a range of fluoride impurities from 1–1400 mg/L. A set of experiments are done to analyze the filtration efficiency of the sandbag filter against fluoride impurities after incorporating different amounts (e.g., 0.2, 2 kg) and a combination of GAC and BC. A combination of filler GAC and BC (1 kg each) have exhibited excellent results with 100% fluoride removal efficiency against 5 mg/L fluoride impurities for an entire experimental time of 165 min. It is because of the synergetic effect of adsorption caused by the high surface area (739 m2/g) of GAC and hydroxyapatite groups in BC. The data from remediation experiments using individual GAC and BC are fitted into the Langmuir and Freundlich Isotherm Models to check their adsorption mechanism and determine GAC and BC’s maximum adsorption capacity (Qm). The remediation data for both GAC and BC have shown the better fitting to the Langmuir Isotherm Model with a high R2 value of 0.994 and 0.970, respectively, showing the excellent conformity with monolayer adsorption. While the GAC and BC have presented negative Kf values of −1.08 and −0.72, respectively, for Freundlich Model, showing the non-conformity to multilayer adsorption. The Qm values obtained from Langmuir Model for GAC is 6.23 mg/g, and for BC, it is 9.13 mg/g. The pH study on adsorption efficiency of individual GAC and BC against 5 mg/L of fluoride impurities indicates the decrease in removal efficiency with an increase in pH from 3 to 9. For example, BC has shown removal efficiency of 99.8% at pH 3 and 99.5% at pH 9, while GAC has exhibited removal efficiency of 96.1% at pH 3 and 95.9% at pH 9. Importantly, this study presents the significance of the synergetic application of GAC and BC in the filters, where GAC and BC are different in their origin, functionalities, and surface characteristics. 

During the past decade, cellulose nanofibrils (CNFs) have shown tremendous potential as a building block to fabricate new advanced materials that are both biocompatible and biodegradable. The excellent mechanical properties of the individual CNF can be transferred to macroscale fibers through careful control in hydrodynamic alignment and assembly processes. The optimization of such processes relies on the understanding of nanofibril dynamics during the process, which in turn requires in situ characterization. Here, we use a shear-free mixing experiment combined with scanning small-angle X-ray scattering (scanning-SAXS) to provide time-resolved nanoscale kinetics during the in situ assembly of dispersed cellulose nanofibrils (CNFs) upon mixing with a sodium chloride solution. The addition of monovalent ions led to the transition to a volume-spanning arrested (gel) state. The transition of CNFs is associated with segmental aggregation of the particles, leading to a connected network and reduced Brownian motion, whereby an aligned structure can be preserved. Furthermore, we find that the extensional flow seems to enhance the formation of these segmental aggregates, which in turn provides a comprehensible explanation for the superior material properties obtained in shear-free processes used for spinning filaments from CNFs. This observation clearly highlights the need for different assembly strategies depending on morphology and interactions of the dispersed nanoparticles, where this work can be used as a guide for improved nanomaterial processes.