Book Chapters

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Carbon-metal sulfide nanomaterial photocatalysts for environmental remediation
(Elsevier, 2024) Hlekelele, Lerato; Mdlalosem, Lindani M; Nomadolo, Elizabeth N; Mtibe, Asanda; Chauke, Vongani; Makgwane, Peter R; Kumar, Naveen
The combination of transition metals and sulfides creates a class of elite semiconductor materials that are capable of forming important electrochemical reactions under reasonable conditions. These electrochemical reactions have been shown to be beneficial in environmental remediation and other applications. Some metal sulfides have been shown to have an edge over metal oxides, including their narrow band gaps and their sulfur edges with lone pairs which is suitable for photocatalytic reactions. However, metal sulfides have problems associated with photocorrosion and the short lifetime span of the photogenerated charge carriers. There are various ways scientists have implemented to increase the viability of metal sulfides as photocatalysts, in particular, using carbonaceous materials. The formation of hybrid heterostructures between metal sulfides and carbonaceous materials (graphitic carbon nitride) is one of the most studied methods of increasing the separation of charge carriers. The most studied types of heterostructures are Type-I, Type-II, and the p-n junctions, all with their advantages and disadvantages. Characterization techniques such as photoluminescence and transient photocurrent are usually used to demonstrate the usefulness of forming these types of heterojunctions. Apart from the formation of heterojunctions is compositing metal sulfides with conducting carbonaceous materials that do not have a band gap. In this instance, the carbon nanomaterials act as sinks for the photoinduced electrons. In this regard, different types of carbon nanomaterials have been shown to effectively increase the lifespan of the electron and hole pairs including carbon nanotubes, carbon nanofibers, graphene oxide (GO), reduced GO, and biochar, among others.
Development of sustainable biobased polymer and bio-nanocomposite materials using nanocellulose obtained from agricultural biomass
(Routledge, 2020-07) Mtibe, Asanda; Muniyasamy, Sudhakar; Motaung, TE; Godfrey, Linda K; Görgens, JF; Roman, H
Biobased polymer and bio-nanocomposites have provided significant improvement in material science, moving towards the development of green materials to replace petro-based materials. The present study investigated the value-added utilisation of agriculturalbiomass residues derived from sugar cane bagasse and maize stalks for the development of biobased polymer and bio-nanocomposite materials for specific applications. In this study, extraction of cellulose and nanocellulose of environmentally friendly polymeric materials and their composite peoducts were studied. The study showed that the incorporation of nanocellulose into biopolymer matrix could produce bio-nanocomposites for specific uses in various applications, mainly in the biomedical and green packaging sectors.
Durable PLA Bioplastics
(Elsevier, 2024) Sinha Roy, Jayita; Ray, Suprakas S
Bioplastics are special plastics manufactured from biobased polymers and can potentially contribute to the circular plastics economy. In this direction, polylactic acid or polylactide (both abbreviated as PLA) is the most important commercially available polymer whose monomeric unit, lactic acid, can be produced from renewable resources. PLA has good thermal plasticity and mechanical properties and can be readily molded. During the manufacturing of PLA-based plastic products, the carbon footprint is approximately 75% lower than that of conventional plastic products. In the context of life cycle assessment and the eco-profile (input and output from the manufacturing process) of PLA, benefits and drawbacks, strategies for overcoming the drawbacks, and the trend of applications, it is worthy to develop PLA-based durable products considering regenerative technical approach. Therefore, this chapter reports recent progress in developing durable PLA bioplastics for various applications. Various strategies have been critically summarized, such as plasticization, copolymerization, and melt blending with different tough polymers, rubbers, thermoplastic elastomers, and nanomaterials. Changing the processing technology, modification of PLA by chemical methods or cross-linking and grafting, and annealing can improve the properties of PLA, which are also discussed in this chapter.
Green fabrication techniques for transparent wood composites: Pioneering sustainable materials for the future
(Cambridge Scholars Publishing, 2024) Simelane, NP; Olatunji, OS; Mathew, Maya J; Andrew, Jerome E
As the world battles with environmental challenges and the need for sustainable alternatives to conventional building materials such as glass, transparent wood composites have emerged as a promising solution. Transparent wood composites, derived from renewable and abundant wood resources, offer a unique combination of strength, thermal insulation, and optical transparency. This chapter explores the latest progress in transparent wood composites, focusing on innovative and eco-friendly fabrication techniques that pave the way for widespread adoption in various applications. It highlights using sustainable wood sources, such as fast-growing trees, and reducing energy-intensive processing steps. The chapter also explores other emerging technologies, including nanocellulose reinforcements and bio-based polymers, that have the potential to revolutionize the fabrication of transparent wood composites. Through a comprehensive review of recent advancements and prospects, this chapter aims to provide researchers with valuable insights into the exciting world of transparent wood composites. Focusing on green fabrication techniques underscores the critical role transparent wood composites can play in building a more sustainable and environmentally responsible future.
Marine microbial pharmacognosy: Prospects and perspectives
(Springer, 2020-11) Mohanrasu, K; Guru Raj Rao, R; Sudhakar, Muniyasamy; Raja, R; Jeyakanthan, J; Arun, A; Nathani, NM; Mootapally, C; Gadhvi, IR; Maitreya, B; Joshi, CG
Modern scientific advancements and research on marine microbes has revealed their significance as producers of therapeutic products useful in treating various human diseases. Microbes in marine habitat have evolved to adapt to the harsh condition that prevails in the ocean. Their struggle to compete for space and nutrients has paved way for the synthesis of different novel enzymes possessing distinctive characteristics. Thus, marine habitat hosts many remarkable microorganisms that offer unique biologically active compounds, enzymes endowed with astonishing properties, and mechanism to survive in extreme environmental conditions. The utilization of marine biotic resources grows at an extraordinary growth rate of 12% per annum and is evident from about 4900 patents filed connected with marine genetic resources and 18,000 natural compounds. This concern has boosted research all over the world to explore the untapped potential hidden in marine microbes, which has lot of biotechnological applications that includes bioactive compounds (metabolites) for therapeutics, novel enzymes, cosmetics, and nutraceuticals. This book chapter will meticulously deliberate the utilization of marine resources by biotechnological applications for therapeutics like antibiotics, chemical compounds, biopolymer, enzymes, and various microbial biomedical purposes such as drug delivery and tissue engineering from marine biota (bacteria, fungi, and algae).
Metal oxide nanocomposites for adsorption and photoelectrochemical degradation of pharmaceutical pollutants in aqueous solution
(Springer, 2020-04) Mdlalose, Lindani M; Chauke, Vongani P; Nomadolo, Elizabeth N; Msomi, P; Setshedi, Katlego Z; Chimuka, L; Chetty, Ashlen; Ama, OM; Ray, Suprakas S
The global deterioration of water quality which is associated with industrialisation, urbanisation, and a growing population is reaching critical levels and thus needs to be addressed urgently. Common pollutants that are discharged from industries and sewage plants include unknown toxic chemicals, heavy-metals and micro-organisms; these are well known and thoroughly studied. Of growing and great concern to both human and animal health is the new emerging class of pollutants known as endocrine disruptor chemicals (EDCs) or emerging organic compounds (EOCs); these are frequently associated with residues from pharmaceutical industries, i.e. they comprise of common drugs such as antibiotics, medication for chronic illnesses, pain killers. Regrettably, the traditional water purification systems cannot fully remove these pollutants, thus they are found in various water systems in minute concentrations. The danger is in the long run accumulative exposure to humans, animals and the environment. There are several methods that have been developed, reported and used for the removal of these pollutants. Several removal or remediation technologies have been studied and reported for the mineralisation of these emerging organic pollutants and of interest to this work is photocatalysis using light harvesting materials such TiO2 (i.e. semiconductors) and electrochemistry. The drawbacks associated with semiconductors are low quantum yields that emanate from rapid recombination of photo-generated electrons and holes with very low lifetimes. To overcome these drawbacks and to enhance degradation, an electrical external field can be applied across the catalyst or semiconductor to induce special separation of photo-generated electron hole pair to allow a sink for the electrons in a process called photoelectrochemistry. This chapter highlights the reported mineralisation of organic pollutants photoelectrochemistry using semiconductors; it also highlights the efficiency of photoelectrocatalysis when compared with photocatalysis alone.
An overview of nanotoxicological effects towards plants, animals, microorganisms and environment
(Springer, 2020-03) Ananthi, V; Mohanrasu, K; Boobalan, T; Anand, K; Chuturgoon, A; Balasubramanian, V; Yuvakkumar, R; Arun, A; Sudhakar, Muniyasamy; Krishnan, A; Chuturgoon, A
In recent years, nanotechnology has reached the limelight of research in applications of medicine and technology. Due to its onset, huge varieties of nanoparticles possessing significant characters are synthesized with broad application fields. Even though these particles are infesting our present life; conflictual views regarding their medical and biological effects are debatable. The non biodegradable nature and nanosize are the alarming features of the nanoparticles that confront potential threats to both environment and biomedical field on its expanding usage. NPs synthesized from heavy metals like lead, mercury and tin are proclaimed as stringent and stable compounds for degradation, hence results in environmental biohazards. The extensive applications of silver nanoparticles in biosensing, cosmetics, medical devices, food and clothing products inflates its human exposure and obviously resulted in toxicity (short and long term). In vitro studies revealed various cytotoxic effects in the cells of mammals such as brain, liver, lung, skin, reproductive organs and vascular system. Furthermore, ingestion, inhalation or injection of nanoparticles in intraperitoneal region resulted in toxic effect of multiple organs inclusively brain. Accounting the metal nanoparticles biohazardous effects like ROS (Reactive oxygen species) generation, DNA damage, protein denaturation and lipid peroxidation has been proved on carbon based nanoparticles, organic lipid based nanoparticles, mineral based nanoparticles, nano diamonds, nano composites, etc. Although, nanotechnology has become an advent field of research nowadays, it is importing significant environmental and health hazards thus couldn’t be beneficial to both society and economy.
Phytic acid: A novel phosphate bio-Based flame retardant
(Springer Nature, 2024-11) Sikhosana, ST; Mochane, MJ; Malebo, NJ; Mokhena, TC; Mofokeng, Tladi G; Sadiku, ER; Mokhena, TC; Mochane, MJ; Sadiku, ER; Ray, SS
The development and application of sustainable flame-retardant agents have become a research hotspot due to the urgent need for eco-friendly materials and the demand for a sustainable environmental protection. Phytic acid has gained popularity as a natural substance that is present in plant seeds with the potential to be a bio-based flame retardant. Its distinct structure, which consists of six phosphate groups, connected to a myoinositol core, confers inherent flame retardancy, making it a suitable candidate for fire safety in polymeric materials. Phytic acid can be added to polymer matrices through physical mixing, chemical grafting, or covalent bonding. This alters the thermal and mechanical properties of the resulting flame-retardant composite, as well as its fire performance. Ongoing research aims to maximize the potential of phytic acid in different polymeric systems, with the goal of creating safe, eco-friendly, and sustainable materials for fire safety applications in fields, such as: construction, automotive, electronics, and textiles.
Recent advances on the use of chitin and its derivatives as flame retardants for different polymeric materials
(Springer, 2024-11) Mtibe, Asanda; Hlekelele, Lerato; Mathew, Maya J; Khumalo, VM; Mokhena, TC; Mokhena, Teboho Clement; Mochane, Mokgaotsa Jonas; Sadiku, Emmanuel Rotimi; Ray, Suprakas S
There is an increase in the usage of plastic materials in various applications and due to their potential risk to burn easy and widespread the flames, there is a necessity the use of flame retardants to reduce the risk of fire hazard. Conventional flame retardancy such as halogenated flame retardants have been used but showed drawbacks. Due to environmental awareness and health concerns the use of halogenated flame retardants have been outlawed in most developed countries which opened an opportunity for development of ecofriendly flame retardancy. This present study highlights the use of chitin and chitin derivatives as flame retardants. The modification of chitin and chitin derivatives is discussed. The mechanism of flame retardants is also thoroughly discussed in this study. In addition, current status and new developments of chitin-based flame retardants are also discussed.
Synthetic, natural derived lipid nanoparticles and polymeric nanoparticles drug delivery applications
(Springer, 2020-01) Mohanrasu, K; Siva Prakash, G; Boobalan, T; Ananthi, V; Dinesh, GH; Anand, K; Muniyasamy, Sudhakar; Chuturgoon, A; Arun, A; Krishnan, A; Chuturgoon, A
In modern therapeutic field, the delivery to the desired site is a crucial bottleneck that needs to be addressed for efficacy and potency of the administrated drug. The recent advancements in the field of nanotechnology has enabled researchers to deliver the drug and other diagnostic agents without unfavourabel effect in huma. Though drug delivery system (DDS) is highly advanatageous, the clinical success rate depends on the appropriate carrier molecules which precisely recognise the target site for the release of drug and its biocompatibility. To overcome this concern both synthetic and naturally derived liip-based nano carriers are the preeminent option as it is biocompatible, non-toxic, enhances the bioavailabity of poorly absorbed drugs, drug release modulation flexibility, improved drug loading capacity and stability.
The use of plastic waste in road construction
(Alive2green, 2021-12) Mturi, George AJ; O’Connell, Johan S; Akhalwaya, Imraan; Ojijo, Vincent O; Mofokeng, Tladi G; Ncolosi, Nonzwakazi; Smit, Michelle A; De Jager, Peta
Recycled plastics are being investigated worldwide not only as a green investment, but also for improved pavement durability (Milad et al., 2020). The objectives of the study were to screen, evaluate and implement existing international technologies in line with South African design standards and specifications for materials in road construction. The main research question was whether low value waste plastics can be optimised as alternative road construction materials in South Africa.

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