Electrospun Nanomaterials: Biotechnology, Food, Water, Environment, and Energy

Over the past decade, electrospinning and electrospraying techniques have become affordable platform techniques for growing numbers of students, researchers, academics, and businesses around the world, producing organic and inorganic nanofibres and nanoparticles for a range of purposes. This review illustrates various advances in the science and engineering of electrospun nanomaterials and their applicability in meeting the growing needs within five crucial sectors: clean water, environment, energy, healthcare, and food. Although most of these sectors are principally dominated by synthetic polymer systems, the emergence of natural polymer and hybrid natural-synthetic electrospun polymer systems offers particular advantages. Current scientific and materials engineering advancements have resulted in highly competitive nanofibre, electrospun products, offering credible solutions to real-world applications.

Characterization of Cellulose Microfibrils Obtained from Hemp

Microfibrillated cellulose was extracted from hemp fibres using steam explosion pretreatment and high-intensity ultrasonic treatment (HIUS). The acquired results after steam explosion treatment and water and alkali treatments are discussed and interpreted by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was used to examine the microstructure of hemp fibres before and after each treatment. A fibre size analyser was used to analyse the dimensions of the untreated and treated cellulose fibrils. SEM observations show that the sizes of the different treated fibrils have a diameter range of several micrometres, but after HIUS treatment fibres are separate from microfibrils, nanofibres, and their agglomerates.

Development of Sustainable Technology to Produce Jute-Ramie Blended Textile and Its Applications

Ramie (Boehmeria nivea), commonly known as China grass, is the strongest and finest plant fibre which is considered one of the valuable textile entities. Despite its unique characteristics, ramie has received reasonably less importance specially in the Indian subcontinent due to unavailability of appropriate postharvesting and processing technologies. With increase in global environmental awareness, the alternative (to cotton) cellulosic natural fibre “ramie” is gaining importance in the international textile domain. Sustainable methods and technologies which could trigger the utilization of ramie fibre are in demand worldwide. This paper will describe the developments carried out in the areas of postharvesting and spinning process of ramie. An ecofriendly degumming technology of ramie fibre has been elaborated along with suitable fibre processing route of ramie-jute blends that will bring new avenue for manufacturing jute diversified market acceptable products.

A Mechanical Analysis of In Situ Polymerized Poly(butylene terephthalate) Flax Fiber Reinforced Composites Produced by RTM

This work addresses mechanical characterization in tension of woven flax fabric reinforced in situ polymerized poly(butylene terephthalate) composites, produced by the RTM technique. A brief description of the developed RTM set-up is made and the composite manufacturing details are presented. A morphological analysis of the mechanically characterized materials by Scanning Electronic Microscopy (SEM) is also made. The produced neat polymer (pCBT) showed a brittle behavior and mechanical properties lower than those found in the literature. Its reinforcement with woven flax fabric resulted in an enhancement of both tensile strength and stiffness. The obtained results can be significantly improved by the polymer modifying chemically , optimizing the control of the processing parameters, and subjecting flax fibers to a surface treatment compatible with the CBT 160 resin.

Polylactic Acid (PLA) Composite Films Reinforced with Wet Milled Jute Nanofibers

In the present study, waste jute fibers formed in textile industries were wet pulverized to nanoscale using high energy planetary ball milling. The rate of refinement of uncleaned jute fibers having noncellulosic contents was found slower than the cleaned jute fibers. This behavior is attributed to the strong holding of fiber bundles by noncellulosic contents which offered resistance to the defibrillation during wet milling. In addition, the pulverization of fibers in the presence of water prevents the increase in temperature of mill which subsequently avoided the sticking of material on the milling container. After three hours milling, the diameter of nanofibers was observed around 50 nm. In the further stage, obtained nanofibers were incorporated under 1 wt%, 5 wt%, and 10 wt% loading into polylactic acid composite films. The potentials of jute nanofibers were investigated for improvement in mechanical and barrier properties of films. The maximum improvement in mechanical properties was observed in case of 5 wt% composite film where Young’s modulus was increased to 3.3 GPa from 1.0 GPa as compared with neat PLA film.

Looking for Links between Natural Fibres’ Structures and Their Physical Properties

Natural fibres have excited growing attention in the last decade since they offer the potential to act as candidates substituting for man-made fibres as composite reinforcements. Their superiority over synthetic fibres is that they are environmentally friendly and biodegradable. Numerous industrial sectors are interested in such composites, including but to name a few the aeronautical and the automotive fields. However natural fibres tend to suffer from large variability in properties compared to the “traditional” man-made fibres, and the performance of their composites often does not conform to that theoretically predicted from single-fibre tests. This study investigates the properties of the single fibres. The mechanical properties of the fibres were correlated to their microstructure. There are factors that were found to contribute to the reported variability, some of which are inherent in the fibres and some are related to testing parameters.

The Effect of Fibre Composition and Washing Conditions upon Hand Properties of Knitted Materials

The behaviour of knitted plated jersey materials made from natural and man-made fibres was tested after certain washing conditions. Surface density and thickness of investigated materials differed insignificantly, from 206 g/m2 up to 222 g/m2 and from 0.56 mm up to 0.79 mm, respectively. Special device for textile materials hand evaluation based on the principle of pulling of a disc-shaped specimen through a rounded hole was used. The aim of this study was to investigate the effect of materials’ fibre composition and washing conditions upon the changes of hand properties of knitted materials. Analysis of obtained results showed that, during washing, textile materials shrink and become more dense and rough, and their rigidity increases as well. Thus, the most significant effect of 5-cycle washing was obtained for knitted material with bamboo fibres.

Influence of Hydroxyethyl Cellulose Treatment on the Mechanical Properties of Jute Fibres, Yarns, and Composites

Jute yarns were treated by tap water with and without tension at room temperature for 20 minutes and then dried. Fibre and yarn strength were measured before and after treatment. Unidirectional (UD) composites were made by both treated and untreated yarns with and without applying hydroxyethyl cellulose (HEC) as size material. Water-treated jute yarns without tension and composites made of those yarns showed decreased strength, and water treated jute yarns with tension and composites made of those yarns showed increased strength with respect to raw yarns and composites made of raw yarns. However, no specific trend was noticed for fibre tensile strength and tensile modulus. HEC sized yarns showed up to 12% higher failure load with respect to unsized yarns, and composites made of HEC sized yarns showed up to 17% and 12% increase in tensile strength and tensile modulus, respectively, compared to composites made of similar types of unsized yarns.