Teboho Motsoeneng | University of South Africa (original) (raw)

Papers by Teboho Motsoeneng

Research paper thumbnail of Structure and Properties of Lignin‐Based Biopolymers in Polymer Production

Soil Microenvironment for Bioremediation and Polymer Production

Research paper thumbnail of Morphology and Properties of Electrospun PCL and Its Composites for Medical Applications: A Mini Review

Applied Sciences, 2019

Polycaprolactone (PCL) is one of the most used synthetic polymers for medical applications due to... more Polycaprolactone (PCL) is one of the most used synthetic polymers for medical applications due to its biocompatibility and slow biodegradation character. Combining the inherent properties of the PCL matrix with the characteristic of nanofibrous particles, result into promising materials that can be suitable for different applications, including the biomedical applications. The advantages of nanofibrous structures include large surface area, a small diameter of pores and a high porosity, which make them of great interest in different applications. Electrospinning, as technique, has been heavily used for the preparation of nano- and micro-sized fibers. This review discusses the different methods for the electrospinning of PCL and its composites for advanced applications. Furthermore, the steady state conditions as well as the effect of the electrospinning parameters on the resultant morphology of the electrospun fiber are also reported.

Research paper thumbnail of Cellulose Nanocrystals‐Based Composites

Research paper thumbnail of Nanomaterials: Types, Synthesis and Characterization

Nanoparticles are generally defined as particles having one or more dimensions of sizes ranging f... more Nanoparticles are generally defined as particles having one or more dimensions of sizes ranging from 1 to 100 nm. Nanoparticles can be classified into organic, inorganic and carbon-based materials. In comparison with conventional micro-size particles, nanoparticles show enhanced properties, such as high reactivity, strength, surface area, sensitivity and stability due to their nanosize. Various preparation methods, viz. physical, chemical and mechanical, have been employed to synthesize different nanoparticles. This chapter presents an overview on nanoparticles and their types, properties, synthesis methods and application in bioconversion of biomass into biofuels.

Research paper thumbnail of The effect of crystalline phase morphology on the structure and properties of polypropylene impact copolymers

Research paper thumbnail of Cellulose Nanocrystals‐Based Composites

Research paper thumbnail of Structure and Properties of Lignin‐Based Biopolymers in Polymer Production

Research paper thumbnail of Syntheses of benzhydryl 2-propanoyl-functionalized trithiocarbonates and its use as chain transfer agents in the RAFT polymerization of styrene

Research paper thumbnail of The effect of filler localization on the properties of biopolymer blends, recent advances: A review

Research paper thumbnail of RAFT polymerization of styrene mediated by oxazolyl-functionalized trithiocarbonate RAFT agents

Research paper thumbnail of Structure and properties of a β -nucleated polypropylene impact copolymer

Polymer International, 2014

The surface dielectric properties of acid-etched low-density polyethylene (LDPE) were analysed in... more The surface dielectric properties of acid-etched low-density polyethylene (LDPE) were analysed in the frequency range from 20 Hz to 200 kHz. Samples were treated with various acids for a period of one hour, at temperatures ranging from 20 to 70 ∘ C. After the treatment, the samples were analysed with Fourier transform infrared spectroscopy, revealing chemical and crystallinity changes on the surface, as a direct result of the treatment. The sample surfaces were analysed using atomic force microscopy. The micrographs show that the acid treatment increases the roughness of the samples. Compared to untreated LDPE, the etched samples may exhibit significantly different conductance values at low frequencies. It is also observed that an increase in the acid treatment temperature can result in lower values of conductance and susceptance compared to untreated samples. LDPE films with low value of surface AC conductivity after acid treatment are potentially useful substrates for high-speed electro-sensing applications. The presented results indicate that a suitable choice of acid treatment of LDPE can effect surface polarization while preserving low values of surface AC conductivity of the polymer.

Research paper thumbnail of Investigation of the crystalline phase morphology of a β-nucleated impact polypropylene copolymer

Journal of Applied Polymer Science, 2014

This study covers the preparation and the characterization of b-nucleated impact polypropylene co... more This study covers the preparation and the characterization of b-nucleated impact polypropylene copolymer (NA-IPC). Calcium stearate (CaSt), as well as pimelic (Pim) and adipic (Adi) acids, were doped into IPC as mono-or bicomponent nucleating agents (NAs) at varying mass ratios. Possible chemical interactions between the NAs and with IPC, as well as the effect of the NAs on the crystallization behavior and nonisothermal crystallization kinetics, were investigated. DSC and XRD results revealed that IPC nucleated with Pim and Pim-CaSt nucleants induced up to 90% b-crystals, whereas Adi and Adi-CaSt formed only about 17% b-crystals. This was associated with the strong nucleation efficiency of Pim. The nonisothermal crystallization kinetics showed that the crystallization of IPC and NA-IPC followed a three-dimensional growth with athermal nucleation mechanism. FTIR showed that none of the NAs chemically reacted with IPC, and the chemical structure of the polymer was thus intact during the treatment. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39923.

Research paper thumbnail of Structure and Properties of Lignin‐Based Biopolymers in Polymer Production

Soil Microenvironment for Bioremediation and Polymer Production

Research paper thumbnail of Morphology and Properties of Electrospun PCL and Its Composites for Medical Applications: A Mini Review

Applied Sciences, 2019

Polycaprolactone (PCL) is one of the most used synthetic polymers for medical applications due to... more Polycaprolactone (PCL) is one of the most used synthetic polymers for medical applications due to its biocompatibility and slow biodegradation character. Combining the inherent properties of the PCL matrix with the characteristic of nanofibrous particles, result into promising materials that can be suitable for different applications, including the biomedical applications. The advantages of nanofibrous structures include large surface area, a small diameter of pores and a high porosity, which make them of great interest in different applications. Electrospinning, as technique, has been heavily used for the preparation of nano- and micro-sized fibers. This review discusses the different methods for the electrospinning of PCL and its composites for advanced applications. Furthermore, the steady state conditions as well as the effect of the electrospinning parameters on the resultant morphology of the electrospun fiber are also reported.

Research paper thumbnail of Cellulose Nanocrystals‐Based Composites

Research paper thumbnail of Nanomaterials: Types, Synthesis and Characterization

Nanoparticles are generally defined as particles having one or more dimensions of sizes ranging f... more Nanoparticles are generally defined as particles having one or more dimensions of sizes ranging from 1 to 100 nm. Nanoparticles can be classified into organic, inorganic and carbon-based materials. In comparison with conventional micro-size particles, nanoparticles show enhanced properties, such as high reactivity, strength, surface area, sensitivity and stability due to their nanosize. Various preparation methods, viz. physical, chemical and mechanical, have been employed to synthesize different nanoparticles. This chapter presents an overview on nanoparticles and their types, properties, synthesis methods and application in bioconversion of biomass into biofuels.

Research paper thumbnail of The effect of crystalline phase morphology on the structure and properties of polypropylene impact copolymers

Research paper thumbnail of Cellulose Nanocrystals‐Based Composites

Research paper thumbnail of Structure and Properties of Lignin‐Based Biopolymers in Polymer Production

Research paper thumbnail of Syntheses of benzhydryl 2-propanoyl-functionalized trithiocarbonates and its use as chain transfer agents in the RAFT polymerization of styrene

Research paper thumbnail of The effect of filler localization on the properties of biopolymer blends, recent advances: A review

Research paper thumbnail of RAFT polymerization of styrene mediated by oxazolyl-functionalized trithiocarbonate RAFT agents

Research paper thumbnail of Structure and properties of a β -nucleated polypropylene impact copolymer

Polymer International, 2014

The surface dielectric properties of acid-etched low-density polyethylene (LDPE) were analysed in... more The surface dielectric properties of acid-etched low-density polyethylene (LDPE) were analysed in the frequency range from 20 Hz to 200 kHz. Samples were treated with various acids for a period of one hour, at temperatures ranging from 20 to 70 ∘ C. After the treatment, the samples were analysed with Fourier transform infrared spectroscopy, revealing chemical and crystallinity changes on the surface, as a direct result of the treatment. The sample surfaces were analysed using atomic force microscopy. The micrographs show that the acid treatment increases the roughness of the samples. Compared to untreated LDPE, the etched samples may exhibit significantly different conductance values at low frequencies. It is also observed that an increase in the acid treatment temperature can result in lower values of conductance and susceptance compared to untreated samples. LDPE films with low value of surface AC conductivity after acid treatment are potentially useful substrates for high-speed electro-sensing applications. The presented results indicate that a suitable choice of acid treatment of LDPE can effect surface polarization while preserving low values of surface AC conductivity of the polymer.

Research paper thumbnail of Investigation of the crystalline phase morphology of a β-nucleated impact polypropylene copolymer

Journal of Applied Polymer Science, 2014

This study covers the preparation and the characterization of b-nucleated impact polypropylene co... more This study covers the preparation and the characterization of b-nucleated impact polypropylene copolymer (NA-IPC). Calcium stearate (CaSt), as well as pimelic (Pim) and adipic (Adi) acids, were doped into IPC as mono-or bicomponent nucleating agents (NAs) at varying mass ratios. Possible chemical interactions between the NAs and with IPC, as well as the effect of the NAs on the crystallization behavior and nonisothermal crystallization kinetics, were investigated. DSC and XRD results revealed that IPC nucleated with Pim and Pim-CaSt nucleants induced up to 90% b-crystals, whereas Adi and Adi-CaSt formed only about 17% b-crystals. This was associated with the strong nucleation efficiency of Pim. The nonisothermal crystallization kinetics showed that the crystallization of IPC and NA-IPC followed a three-dimensional growth with athermal nucleation mechanism. FTIR showed that none of the NAs chemically reacted with IPC, and the chemical structure of the polymer was thus intact during the treatment. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39923.