With increasing environmental and ecological concerns due to the use of petroleum-based chemicals and products, the synthesis of fine chemicals and functional materials from natural resources is of great public value. Nanocellulose may prove to be one of the most promising green materials of modern times due to its intrinsic properties, renewability, and abundance. In this review, we present nanocellulose-based materials from sourcing, synthesis, and surface modification of nanocellulose, to materials formation and applications. Nanocellulose can be sourced from biomass, plants, or bacteria, relying on fairly simple, scalable, and efficient isolation techniques. Mechanical, chemical, and enzymatic treatments, or a combination of these, can be used to extract nanocellulose from natural sources. The properties of nanocellulose are dependent on the source, the isolation technique, and potential subsequent surface transformations. Nanocellulose surface modification techniques are typically used to introduce e...

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Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

Tremendous efforts have been dedicated to developing effective and eco-friendly approaches for separation of oil–water mixtures Challenges remain in terms of complex processing, high material cost, low efficiency, and scale-up problems Inspired by the tubular porosity and hierarchical organization of wood, a strong, mesoporous, and hydrophobic three-dimensional wood structure is created for selective oil/water separation A delignified wood template with hydrophilic characteristics is obtained by removal of lignin The delignified wood template is further functionalized by a reactive epoxy–amine system This wood/epoxy biocomposite reveals hydrophobic/oleophilic functionality and shows oil absorption as high as 15 g/g The wood/epoxy biocomposite has a compression yield strength and modulus up to 18 and 263 MPa, respectively, at a solid volume fraction of only 12% This is more than 20 times that of cellulose-based foams/aerogels reconstructed from cellulose nanofibrils The favorable performance is asc

Wood Nanotechnology for Strong, Mesoporous, and Hydrophobic Biocomposites for Selective Separation of Oil/Water Mixtures

Functionalized Cellulose for Water Purification, Antimicrobial Applications, and Sensors

Nature has endowed many of its living systems with functional structures with highly tuned wettability. Inspired by nature, scientists began to mimic these natural templates and as a result a wide spectrum of biomimetic superhydrophobic surfaces are fabricated. Fluorinated synthetic materials are currently used on an industrial scale to produce superhydrophobic surfaces. The negative impact of fluorinated substances on human health together with growing environmental concerns has prompted researchers to adopt safer routes with minimal use of fluorinated compounds. This has led to increased focus on bio-inspired studies. Current research on the fabrication and characterisation of superhydrophobic materials aims to use fluorine-free reagents such as siloxane polymers and long-chain fatty acids. In this context, this review attempts to highlight the recent progress in fluorine-free superhydrophobic surfaces and important features of their design, synthesis and fabrication that would potentially broaden their application in various fields. This review also aims to provide insights into technical breakthroughs in manufacturing of these materials with the aid of easy-to-understand illustrations. The current challenges regarding scale up, industrial production and marketing of these novel and natural polymer based superhydrophobic materials are also highlighted.

Bio-inspired sustainable and durable superhydrophobic materials: from nature to market

Nanocellulose, as a promising natural material, has recently received much attention because of its remarkable features including recyclability, biocompatibility, low risk of toxicity, and tunable ...

Production of Nanocellulose and Its Applications in Drug Delivery: A Critical Review

Nanocellulose is gaining evident interest from researchers and engineers because of its renewability, biocompatibility, biodegradability, high mechanical strength, abundant hydroxyl groups for potential functionality, and extensive raw materials. Versatile sources are accordingly explored like harvested wood, annual plants, and agricultural residues. However, an abundant shrub plant, Amorpha fruticosa Linn., has not yet been reported for isolating nanocellulose. We accordingly propose a green method with low energy consumption to extract nanocellulose from the vast shrub source via combined grinding and successive homogenization treatments. The derived nanocellulose possesses a fine structure with a diameter of ∼10 nm and an aspect ratio over 1000, high thermal stability with a maximum decomposition temperature of 337 °C, and similar composition with a hydroxyl group and a crystal I structure to that of natural cellulose. The demonstrated nanopaper presents visible light transmittance over 90% and haze be...

Nanocellulose Mechanically Isolated from Amorpha fruticosa Linn.

Solid wood materials and wood–plastic composites as two kinds of lightweight materials are attracting great interest from academia and industry due to their green and recycling nature. However, the relatively lower specific strength limits their wider applications. In particular, solid wood is vulnerable to moisture and decay fungi in nature, resulting in its poor durability for effectively long-term utilization. Inspired from the porous structure of wood, we propose a new design to build a wood-based nanocomposite with higher specific strength and satisfactory durability by in situ generation of organic–inorganic hybrid polymer within wood via a sol–gel method. The derived composite has 50–1200% improvement of impact toughness, 56–192% improvement of tensile strength, and 110–291% improvement of flexural strength over those of typical wood–plastic composites, respectively; and even 34% improvement of specific tensile strength than that of 36A steel; 208% enhancement of hardness; and 156% enhancement of c...

Wood-Based Nanocomposite Derived by in Situ Formation of Organic-Inorganic Hybrid Polymer within Wood via a Sol-Gel Method.

Cellulose-based materials are vulnerable to moisture and microorganisms and thus lose their original mechanical properties and durability; meanwhile, self-cleaning technique as a disruptive nanotechnology of waterproofing is attracting tremendous interest. Here, we develop a facile, cheap, and scalable “top-down” strategy to fabricate a transparent self-cleaning surface for cellulose-based materials by spray-coating a stable emulsion of nano-SiO2 particles. The nanoparticles are precisely synthesized at an average diameter of ∼110 nm via a sol–gel way and finely tailored with hydrophobic function by successive modification of poly(dimethylsiloxane) (PDMS) and (heptadecafluoro-1,1,2,2-tetradecyl)trimethoxysilane (17F). The modified nano-SiO2 particles well-distributed on the microscale rough surface of the cellulose-based materials by spray-coating to form a micro/nano two-tier structure to entrap air for water resistance, and thus build a superhydrophobic surface with static water contact angle (WCA) over...

Facile, Scalable Spray Coating of Stable Emulsion for Transparent Self-cleaning Surface of Cellulose-based Materials

Nanocellulose has many advantages, such as a wide range of sources of raw materials, renewability, biodegradability, high aspect ratio and large specific surface area. It can be potentially used in medicine, electronics, information technology, energy industry, aerospace and some other high-technological fields.  For preparation of nanocellulose, it is particularly important to separate nanocellulose from  raw materials by an environment-friendly method with environmental protection awareness. Consequently, we here report an effective and environmental friendly method to isolate nanocellulose from a shrub plant, i.e.,  Amorpha fruticosa Linn. Firstly, the plant fiber is pretreated with chemicals to remove lignin and hemicellulose; then the derived purified cellulose is pretreated with enzyme hydrolysis, followed by slight treatment of high-pressure homogenization. The results showed that with the assistance of enzyme pretreatment, effective isolation of nanocellulose could be achieved,  resulting in materials with a uniform diameter distribution and an average value of about 10 nm.  The aspect ratio of the derived nanocellulose is greater than 1000. Such results showed that the method was green and effective for nanocellulose isolation, and the derived biomaterial as a unique biocompatible and high-strength biomass nanomaterial could be used in biomedical, environmental protection and other fields.

https://www.udspub.com/ajj/public/index.php/aeb/article/download/420/pdf_1

Nanocellulose isolation from Amorpha fruticosa by an enzyme-assisted pretreatment

In order to improve the decay resistance of wood, we propose a novel method by in-situ hybridization of reactive monomers and nano-SiO 2 within wood porous structure to modify wood structure and chemical components. Glycidyl methacrylate (GMA), and polyethylene glycol-200 dimethacrylate (PEGDMA) were first mixed and then penetrated into poplar wood cell lumen by vacuum/pressure treatments, followed by in-situ hybridization under an initiation condition. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and transmission electron microscopy (TEM) observations described that the polymer-inorganic hybrid nanocomposite filled up cavities and tightly contacted the wood cell wall. Nano-SiO 2 particles were uniformly dispersed into the formed polymer within wood pores. Fourier transform infrared spectroscopy (FTIR) analysis suggested that the nano-SiO 2 probably chemical bonded to the polymer during the monomer polymerization. The derived wood-based polymer-inorganic hybrid nanocomposite exhibited remarkably improvement in decay resistance over the untreated wood as controls. Such treatment could potentially widen the wood applications with outstanding decay resistance.

https://www.udspub.com/ajj/public/index.php/aeb/article/download/168/128

Xiao Zhuo

Papers

Nanocellulose Mechanically Isolated from Amorpha fruticosa Linn.

Wood-Based Nanocomposite Derived by in Situ Formation of Organic-Inorganic Hybrid Polymer within Wood via a Sol-Gel Method.

Facile, Scalable Spray Coating of Stable Emulsion for Transparent Self-cleaning Surface of Cellulose-based Materials

Nanocellulose isolation from Amorpha fruticosa by an enzyme-assisted pretreatment

Improvement of decay resistance of wood by in-situ hybridization of reactive monomers and nano-SiO 2 within wood