Modulating the Properties of Hybrid Nanocellulose Films.

The environmental concerns about petroleum-based polymers drive the search for sustainable alternatives. This paper investigates sustainable cellulose nanocrystal (CNC) films for packaging applications. CNC films are transparent and provide an excellent barrier against oxygen with moderate performance against water vapor.

Can pure cellulose nanofibril films replace polyolefins as water vapor barriers in packaging?

Despite significant research into cellulose nanofibril (CNF) films as substitutes to synthetic plastic materials, commercial applications remain very limited. One major hindrance is the poor water vapor barrier properties of CNF films compared to polyolefins, a critical property for product protection, such as food safety and preservation. To date, it is unknown whether full moisture barrier properties can be achieved with materials made by the assembly of nanofibers and fibrils.

Modulating the chiral nematic structure of cellulose nanocrystal suspensions with electrolytes.

Hypothesis: The iridescent optical properties of films made of cellulose nanocrystals (CNC) are controlled by the pitch and range of the chiral nematic structures. These are further tuned with the addition of electrolyte.

Experiments: Electrolyte type, valency and concentration were varied.

Self-assembly of cellulose nanocrystals of different lengths.

Hypothesis The self-assembly (SA) of cellulose nanocrystals (CNC) in suspensions is important both from the fundamental and advanced technology development perspective. CNC of different lengths self-assemble differently in suspensions by balancing attractive and repulsive interactions which depends strongly on morphology, surface chemistry and concentrations. Experiments Two different commercial CNC samples (CNC-M and CNC-C) of different lengths were dispersed in Milli-Q water at different concentrations (0.

Recent advancements, trends, fundamental challenges and opportunities in spray deposited cellulose nanofibril films for packaging applications.

Plastic packaging is causing a serious environmental concern owing to its difficulty in degrading and micro-particulates' emissions. Developing biodegradable films has gained research attention to overcome ecological and health issues associated with plastic based packaging. One alternative substitute for petroleum-based plastic is nanocellulose based films, having distinguishing characteristics such as biodegradability, renewability, and non-toxicity.

Preparation and benchmarking of novel cellulose nanopaper.

Unlabelled: Synthetic polymers and plastics which are currently used as barrier materials in packaging applications are neither renewable nor biodegradable. Nanopaper, which is obtained by breaking down cellulose fibers into nanoscale particles, have unique properties with the potential to replace synthetic packaging materials, but requires very high energy to mechanically process the fibers into nanopaper. This research investigates whether refining alone can be used to produce nanopaper with sufficient quality for packaging applications.

Rapid Detection of Gram-Positive and -Negative Bacteria in Water Samples Using Mannan-Binding Lectin-Based Visual Biosensor.

Waterborne bacterial infection is a health threat worldwide, making accurate and timely bacteria detection crucial to prevent waterborne disease outbreaks. Inspired by the intrinsic capability of mannan-binding lectin (MBL) in recognizing the pathogen-associated molecular patterns (PAMPs), a visual biosensor is developed here for the on-site detection of both Gram-positive and -negative bacteria. The biosensor was synthesized by immobilization of the MBL protein onto the blue carboxyl-functionalized polystyrene microparticles (PSM), which is then used in a two-step assay to detect bacterial cells in water samples.

One-pot treatment of cellulose using iron oxide catalysts to produce nanocellulose and water-soluble oxidised cellulose.

This research explains the one-pot process of cellulose fibrillation to procure nanocellulose fibres and water-soluble oxidised cellulose using iron oxide catalysts with hydrogen peroxide. The process involved three stages. First, cellulose underwent depolymerisation to form nanocellulose fibres.

Moulding of micropatterned nanocellulose films and their application in fluid handling.

Hypothesis: Well-controlled micropatterned nanocellulose films are able to be fabricated via spray coating onto a micropatterned impermeable moulded surface. The micropattern size is able control the directionality of wicking fluid flow.

Experiments: Using photolithography and etching techniques, silicon moulds with channel widths of 5-500 µm and depths of 6, 12 and 18 µm were fabricated.

An energy efficient production of high moisture barrier nanocellulose/carboxymethyl cellulose films via spray-deposition technique.

Nanocellulose (NC) films are considered as a prospective alternative to non-sustainable packaging materials, however, their higher embodied energy and limited moisture barrier properties are regarded as a huge constraint regarding their commercialization. This study aims to produce films with relatively low environmental impact and improved barrier performance. For this purpose, carboxymethyl cellulose (CMC) and NC were combined, and this resulted in multidimensional advantages.

Exfoliating B. mori silk into high aspect ratio nanofibrils facilitated by response surface methodology.

Silk fiber is formed by an assembly of fibrils. The fibrils can be isolated by a top-down mechanical process called microfibrillation and the fibrils are known as microfibrillated silk (MFS). The process involves chopping, milling, enzyme treatment and high-pressure homogenization.

Impact of structural changes in heteroleptic bismuth phosphinates on their antibacterial activity in Bi-nanocellulose composites.

To study and evaluate the effect of ligand choice and distribution in bismuth phosphinates on toxicity and antibacterial activity, a series of novel diphenyl mono-phosphinato bismuth complexes, [BiPh2(O(O[double bond, length as m-dash])P(H)Ph)] 1, [BiPh2(O(O[double bond, length as m-dash])PPh2)] 2, [BiPh2(O(O[double bond, length as m-dash])PMe2)] 3 and [BiPh2(O(O[double bond, length as m-dash])P(p-MeOPh)2)] 4, were synthesised, characterised and structurally authenticated by X-ray crystallography. Evaluation of their antibacterial activity towards Staphylococcus aureus (S. aureus), methicillin-resistant S.

Polyamide-amine-epichlorohydrin (PAE) induced TiO nanoparticles assembly in cellulose network.

Hypothesis: TiO-NPs-Cellulose composites functionality depends on the retention and dispersion of NPs in the composites. SAXS and SEM can be combined to reveal the effect PAE has on the NPs aggregation, retention and interaction mechanisms in the composites.

Experiments: TiO-NPs-Cellulose sheets were made by first preparing PAE-cellulose suspensions of different PAE dosages (10 and 50 mg of PAE/g fibres).

Development of a Paper-Based Microfluidic System for a Continuous High-Flow-Rate Fluid Manipulation.

The current study describes the development of a disposable paper-based microfluidic system, which unlike its predecessors that are only capable of processing a small amount of fluid, can continuously process the fluid at a high flow rate of up to 1.5 mL/min. The fabrication procedure was clean-room-free and robust, involving the use of a CO laser to engrave the microchannels on a paper substrate, followed by alkenyl ketene dimer treatment to hydrophobize the paper and lamination.

Cellulose nanofibers from recycled and virgin wood pulp: A comparative study of fiber development.

The global abundance of recycled pulp has introduced opportunities for cellulose nanofiber (CNF) production at lower energy due to the partially fibrillated nature of recycled pulp. This study investigated the potential of recycled pulp as a feedstock for CNF production, comparing recycled bleached de-inked pulp (DIP) predominantly from eucalyptus fibers with virgin bleached eucalyptus kraft (BEK) pulp. The specific energy consumption for CNF production with 10,000 PFI refiner revolutions and 1 homogenization pass was 7 % lower with recycled pulp.

Protein Paper from Exfoliated Eri Silk Nanofibers.

The exfoliation of silk fiber is an attractive method to produce silk micro- and nanofibers that retain the secondary structure of native silk. However, most fibrillation methods used to date require the use of toxic and/or expensive solvents and the use of high energy. This study describes a low cost, scalable method to produce microfibrillated silk nanofibers without the use of toxic chemicals by controlling the application of shear using commercially scalable milling and homogenization equipment.

Characterizing highly fibrillated nanocellulose by modifying the gel point methodology.

The characterization of nanocellulose fibres (NC) length is a difficult and indirect measurement which relies on aspect ratio calculation and fibre diameter analysis. The aspect ratio can be directly calculated from the gel point, a parameter obtained from sedimentation experiments. The gel point has been used with macroscopic fibres and microfibrillated cellulose, that easily sediment by gravity.

Nanocellulose for gel electrophoresis.

Hypothesis: Cellulose nanofibres produced by TEMPO-mediated oxidation can form gels. This study presents a proof-of-concept for gel electrophoresis with nanocellulose (NC).

Experiments: TEMPO-oxidised cellulose nanofibre dispersion is chemically cross-linked by inducing amide linkages to produce gel slabs for electrophoretic separation.

Carboxylated nanocellulose foams as superabsorbents.

Hypothesis: Carboxylated nanocellulose fibres formed into foam structures can demonstrate superabsorption capacity. Their performance can be engineered by changing process variables.

Experiments: TEMPO-oxidised cellulose nanofibres of varying concentration and surface charge are produced from hardwood kraft pulp.

Pickering Emulsions Electrostatically Stabilized by Cellulose Nanocrystals.

Cellulose Nanocrystals (CNC) are explored to stabilize oil/water emulsions for their ability to adsorb at the oil/water interface. In this work, the role of electrostatic forces in the CNC ability to stabilize oil/water emulsions is explored using canola oil/water and hexadecane/water as model systems. Canola oil/water and Hexadecane/ water (20/80, v/v) emulsions were stabilized with the addition of CNCs using ultrasonication.

Multi-Layer Filters: Adsorption and Filtration Mechanisms for Improved Separation.

Filters made of cellulose fiber and perlite particles were prepared using a wet laying papermaking technique. Polyamide-amine-epichlorohydrin (PAE) was added to provide wet strength. Filters were prepared at two different total basis weights of 200 and 400 grams per square meter (gsm).

Novel In-situ Precipitation Process to Engineer Low Permeability Porous Composite.

Inspired by the natural precipitation of minerals in soil and rocks, a novel, simple and industrially scalable in-situ precipitation process to produce low permeability porous composites is presented. This process relies on capillary flow in wettable porous composites to absorb and store liquid. In this process, a porous composite first absorbs a salt solution, after which the composite is dipped in a second salt solution.

Bismuth Phosphinates in Bi-Nanocellulose Composites and their Efficacy towards Multi-Drug Resistant Bacteria.

A series of poorly soluble phenyl bis-phosphinato bismuth(III) complexes [BiPh(OP(=O)R R ) ] (R =R =Ph; R =R =p-OMePh; R =R =m-NO Ph; R =Ph, R =H; R =R =Me) have been synthesised and characterised, and shown to have effective antibacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE).

Cationic polyacrylamide induced nanoparticles assembly in a cellulose nanofiber network.

Polyacrylamides of different molecular weight, charges and dosages allow to control the retention and distribution of nanoparticles (NPs) in composites, and optimise composite properties and functionality. Our aim is to evaluate the effect of high molecular weight (13 MDa) cationic polyacrylamide (CPAM) charge and dosage on SiO (74 nm) NP's assembly in cellulose nanofibers composites. Engineered cellulose/SiO composites were investigated by SEM, SAXS and DLS.