Browsing by Author "Wanyama, Aaron"

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3 - Advanced biopolymer-based green composites: their processing and damage mechanism
(ScienceDirect, 2021-09) Mwesigwa, Ronald; Nkomo, Nkosilathi Zinti; Mwasiagi, Josphat Igadwa; Wanyama, Aaron
Composites are constructions of lightweight bearing high toughness and custom-made properties for precise use, globally. In addition, bio-based composites are constructions made from natural and/or synthetic fibers and petroleum-based polymers and/or biodegradable polymers. Furthermore, green composites are constructions obtained from biopolymers and agricultural/natural or biofibers that are more environmentally friendly hence highly sought after worldwide. Currently, green composites are offering enormous benefits that are promoting them in the automotive, packaging, construction, electrical and insulation, furniture, consumer, and household industries among others. This chapter therefore presents advanced biopolymer-based green composites in relation to their processing and damage mechanism. Subtopics covered include processing and characterization of biopolymers, agricultural/natural fibers, and green composites. Various failure and damage mechanisms pertaining to green composites are also covered.
Advanced biopolymer-based green composites: their processing and damage mechanism
(Sustainable Biopolymer Composites : Woodhead Publishing, 2021-09-17) Mwesigwa, Ronald; Nkomo, Nkosilathi Zinti; Mwasiagi, Josphat Igadwa; Wanyama, Aaron
Composites are constructions of lightweight bearing high toughness and custom-made properties for precise use, globally. In addition, bio-based composites are constructions made from natural and/or synthetic fibers and petroleum-based polymers and/or biodegradable polymers. Furthermore, green composites are constructions obtained from biopolymers and agricultural/natural or biofibers that are more environmentally friendly hence highly sought after worldwide. Currently, green composites are offering enormous benefits that are promoting them in the automotive, packaging, construction, electrical and insulation, furniture, consumer, and household industries among others. This chapter therefore presents advanced biopolymer-based green composites in relation to their processing and damage mechanism. Subtopics covered include processing and characterization of biopolymers, agricultural/natural fibers, and green composites. Various failure and damage mechanisms pertaining to green composites are also covered.
Antimicrobial activity of cotton and silk fabrics dyed with Datura stramonium (Jimson weed) plant leaf extracts
(African Journal of Microbiology Research, 2019-11) Musinguzi, Alex; Mwasiagi, Josphat Igadwa; Wanyama, Aaron; Gumisiriza, Onesmas
Functional finishes are agents that are applied to fabrics to make them suitable for specific uses and contribute a specific attribute to a fabric without altering its appearance. In this context, the present study reveals the importance of dyed fabrics with Datura stramonium plant leaf extracts to control antibiotic-resistant bacteria, which have been a threat to human health and posed noticeable challenges confronted with medical physicians in the treatment of many infectious diseases. More still, the importance of using natural dye is not limited to its antimicrobial and other medicine values but also to its wide range of advantages via elimination of environmental pollution due to the usage of synthetic dyes. 100% plain woven, desized, scoured and bleached cotton fabric samples and 100% degummed and bleached hand knitted silk fabric samples were dyed with aqueous extracts from D. stramonium plant leaves in combination with Alum and Iron Sulphate as mordants using post-mordanting method and then tested against two strains of Staphylococus aureus (Gram-positive bacteria) and Pseudomonas aeruginosa (Gram-negative bacteria) using Agar diffusion method as per SN195920-1992 standard. The fastness properties (wash fastness, light fastness and rubbing fastness) of the dyed fabrics were assessed following guidelines from The American Association of Textile Chemists and Colorists (AATCC) and International Organization for Standardisation (ISO) testing methods. Spectrophotometric experiments were employed to evaluate the colour strength (K/S) of the dyed samples. The antimicrobial activity results showed that for both cotton and silk dyed fabric samples; there was an interruption of the microbial growth beneath the fabric and a clear zone of inhibition around the fabric. Dye ability and fastness results showed that dyed fabric samples with D. stramonium extracts using mordants had relatively high colour strength (K/S) values as compared to the control fabrics which were dyed without a mordant and their colorant was more stable to light, rubbing and washing, respectively.