Volume 12 Issue 1

A multistage process was employed to obtain value-added products from brewer’s spent grain (BSG). This paper is focused on the production and characterisation of cellulose nano-fibres (CNF) as one of the products obtained during the complete process. In the first stage, protein-rich liquor was separated via the alkaline (NaOH) treatment of dried BSG and stored for further utilisation. In the second stage, bleaching treatments were conducted to separate cellulose, which was later converted to CNF by high-pressure homogenisation. The lignocellulosic product from each step was analysed for its chemical composition by means of alkaline hydrolysis combined with the HPEAC method. The thermal properties were measured using thermogravimetric analysis (TGA). The morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray diffraction (XRD) was done to observe changes in crystallinity. The nano-cellulose produced can be regarded as a value-added material from the bio-refinery of BSG along with numerous already-reported products.

Wood that is used in outdoor applications is frequently exposed to weathering and is thus prone to fungal degradation. Ways to prevent fungal degradation include keeping the wood dry. The majority of hydrophobic and wood modification systems have been tested only on freshly treated wood. Little information is available on how various wood-based materials perform after a certain period of weathering. To elucidate this question, 17 wood samples were tested from the following species: oak (Quercus), sweet chestnut (Castanea sativa), European larch (Larix decidua), Scots pine heartwood and sapwood (Pinus sylvestris), Norway spruce (Picea abies), and beech (Fagus sylvatica). Moisture performance of the wood samples was improved with thermal modification, wax, oil, and biocide treatment. Specimens were exposed to various degradation-aging factors (blue stain fungi, decay fungi, artificial weathering, and natural weathering). Various moisture performance tests were applied before and after aging: short-term water uptake (tensiometer), long-term water uptake, water vapor tests, drying tests, etc. The water exclusion efficacy of wood was decreased after aging. Aging factors were found to act synergistically and to have a more prominent influence on less durable wood compared to durable or preservative-treated wood. Wax-treated wood performed best, regardless of which moisture performance test was applied.

Thermal spray technology was used to apply a thin layer of copper (Cu metal as an antimicrobial coating) on the surfaces of a number of different solid woods and medium-density fiberboard (MDF) wood composites. The adhesion of a Cu coating to Swietenia macrophylla (mahogany), Quercus (oak), Acer saccharinum (silver maple), Picea (spruce), Pinus strobus (white pine), and MDF was evaluated by a pull-off adhesion test. The resistance of Cu-coated samples to mildew, decay fungi, and water uptake was assessed in the lab. Also, the weathering performance of Cu-coated untreated and heat-treated spruce was evaluated. After proper surface preparation, the adhesion of Cu coatings to hardwood and softwood samples was considered very good, and the adhesion of the Cu coating to MDF was much stronger than the internal bond strength of MDF itself. The Cu coating effectively protected the wood from decay fungi and mildew, while it had no effect on the rate of water absorption and desorption from the wood. After one year of natural weathering in Toronto, Canada, the Cu-coated heat-treated spruce samples had significantly fewer checks than coated, untreated wood. Thermal spray copper coating proved to have the potential to protect wood from biological degradation while also serving as an antimicrobial coating.

Waste cassava tuber fibers (wCTF), derived from the ethanolic fermentation of cassava tubers, have potential use as anatural adsorption immobilization carrier. Ethanol fermentation was conducted using 15% (w/v) glucose-containing mediumat 40 °C for 48 h by Saccharomyces cerevisiae G6-2-2 (1.3 x 1010cells). Ethanol concentration produced by free, wCTF (1.2 g dry weight) adsorbed, wCTFadsorbed-calcium alginate entrapped,and calcium alginate entrapped cellswere 42.10 ± 0.61, 67.35 ± 0.53, 52.10 ± 0.40, and 46.45 ± 0.18 g/L (0.34, 0.45, 0.35, and 0.31 g ethanol/g reducing sugar), respectively. The wCTF adsorbed cells produced a maximum ethanol yield of 82.15 ± 0.48 g/L (0.43 g ethanol/g total sugar) from molasses (20% w/v initial total sugar) after 48 h, compared to 74 g/L to 76 g/L and 48 h to 100 h for the free suspension cells. The increase in ethanol produced by the wCTF adsorbed cells compared to free cells reflected that the cells were protected from environmental stresses and received amino nitrogen from the wCTF that supported growth and ethanol tolerance.

Many environmental advantages of wood in buildings have been thoroughly documented; however, this material’s effects on occupants are not well known or fully comprehended. This research aims to study comfort parameters in a multifunctional room characterised by extensive wood surfaces in comparison with a similar room with more conventional surfaces at Laval University, Quebec, Canada. The objectives of this research focus on determining the thermal, visual, and acoustical similarities and differences between two rooms using on-site surveys. Analysis of instrumental measurements and images of each room’s indoor environment under overcast skies determined the colour and texture of the surfaces. Quantitative and qualitative analyses revealed that both rooms share similar thermal and acoustic comfort parameters, but have contrasting visual characteristics. The colour, knots, and grain of the wood contributed to producing visually warm experiences resulting in a yellowish room, whereas a mix and match of artificial finishes generates a colder, bluish ambiance in the other room. The conclusion suggests that architects and designers should consider the indoor use of wood for its unique visual ambiances that enhance comfort levels.

Residual lignin present in alkali pulps prepared from oil palm (Elaeis guineensis) empty fruit bunch was isolated using an enzymatic method and characterized successfully by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). These pulps were prepared by soda-anthraquinone (AQ) and prehydrolysis (PH) soda-AQ cooking methods (pulp yields were 45.3 and 33.9%, respectively). Py-GC/MS of the residual lignin showed that two pyrolysis products which were indole and methylindole originating from the enzyme (contents 12 to 44%), in addition to eight pyrolysis products originating from syringyl (S) and guaiacyl (G) structure of lignin. Furthermore, palmitic acid was also detected in the residual lignin (contents 0.11 to 0.28%). The residual lignin was subjected to further purification by a cellobiose treatment method, and the quantity of enzyme present in the residual lignin was found to decrease after the treatment. Residual lignin in PH-soda-AQ pulp exhibited a higher S/G ratio (0.86 to 0.98) than that in soda-AQ pulp (0.76 to 0.97). This study showed that the contents of lignin (19 to 44%) and enzyme in enzymatically isolated lignin can be estimated by the Py-GC/MS method.

In the low cost application of vacuum casting in rapid prototyping, a mould cavity with high modulus is necessary for producing plastics parts in small quantity. In this work, a silicone matrix was reinforced with natural fibers to improve the modulus of composites to mould and to reduce the cost of silicone materials. Sisal fiber with different compositions was reinforced with silicone in a compression moulding process. Mechanical properties were studied. An increase in tensile strength, tear strength, and better hardness was observed in sisal fiber composites . The silane-treated fiber improved the adhesion between fiber and matrix and enhanced the mechanical properties of the composites. The swelling method was adopted to determine the cross-linking density of composites through the Flory-Rehner equation. The flexibility of silicone composites decreased for higher fiber loading and there was an increase in cross-linking of the fiber network to improve modulus of the composites. A morphological study was conducted using X-ray tomography and scanning electron microscopy (SEM) to predict the defects, orientation, debonding, fractography, and interfacial adhesion of fiber/matrix composites.

The plant Ensete ventricosum is used in agriculture in Africa. It is a source of fibres, which can be used in the interaction with polymers. This study deals with a material utilization of these fibres with a length of 1 to 2 mm, 2 to 3 mm, and 3 to 5 mm, together with reactoplastics resin ChS Epoxy 1200/324, following requirements of developing countries. Some areas of the African continent suffer from a lack of wood, and material based on epoxy and fibres can substitute for many wood products. The aim of this experiment was to describe basic mechanical properties (tensile strength σm, strain at the break εb, modulus of the elasticity Et, and impact strength an) of the composite material reinforced with fibres of the false banana plant, Ensete ventricosum. The plant, which originated in Ethiopia, is exploitable in developing countries. Geometrical aspects and morphology of the used fibres was characterized by scanning electron microscopy (SEM). The addition of fibres increased the modulus of elasticity and the impact strength, whereas the tensile strength and the strain at break were decreased.