Grey High School speech night 1979
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7383 , http://hdl.handle.net/10962/d1017272
- Full Text:
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7383 , http://hdl.handle.net/10962/d1017272
- Full Text:
Grounds & gardens : adding value to the living space : "Enabling the Academic Project" : 26 years on the greenside
- Authors: Hazell, M
- Language: English
- Type: Text
- Identifier: vital:7959 , http://hdl.handle.net/10962/d1008354
- Description: [A presentation given by Mark Hazell, Manager: Grounds & Gardens at Rhodes University, to the Rhodes University Environmental Committee on the occasion of his retirement from Rhodes University]
- Full Text:
- Authors: Hazell, M
- Language: English
- Type: Text
- Identifier: vital:7959 , http://hdl.handle.net/10962/d1008354
- Description: [A presentation given by Mark Hazell, Manager: Grounds & Gardens at Rhodes University, to the Rhodes University Environmental Committee on the occasion of his retirement from Rhodes University]
- Full Text:
Group photo's of Staff and Student Collaborators
- Authors: Nyokong, Tebello
- Language: English
- Type: still image
- Identifier: vital:7231 , http://hdl.handle.net/10962/d1006061
- Description: Group photo's of Staff and Student collaborators at Rhodes University
- Full Text:
- Authors: Nyokong, Tebello
- Language: English
- Type: still image
- Identifier: vital:7231 , http://hdl.handle.net/10962/d1006061
- Description: Group photo's of Staff and Student collaborators at Rhodes University
- Full Text:
Harnessing the energy of the sun
- Authors: Matiwana, Zamuxolo
- Language: English
- Type: Article
- Identifier: vital:7207 , http://hdl.handle.net/10962/d1006410
- Description: Capturing solar energy was the theme of this year's Barker Lecture delivered by Professor Derek Sehlettwein, an expert electrochemist from Justus-Liebig University in Giessen. Germany
- Full Text:
- Authors: Matiwana, Zamuxolo
- Language: English
- Type: Article
- Identifier: vital:7207 , http://hdl.handle.net/10962/d1006410
- Description: Capturing solar energy was the theme of this year's Barker Lecture delivered by Professor Derek Sehlettwein, an expert electrochemist from Justus-Liebig University in Giessen. Germany
- Full Text:
Improved l-cysteine electrocatalysis through a sequential drop dry technique using multi-walled carbon nanotubes and cobalt tetraaminophthalocyanine conjugates
- Nyoni, Stephen, Mugadza, Tawanda, Nyokong, Tebello
- Authors: Nyoni, Stephen , Mugadza, Tawanda , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7308 , http://hdl.handle.net/10962/d1020385
- Description: Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)–cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc–MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 × 105 M−1 s−1, apparent electron transfer rate constant of 0.073 cm s−1, and a limit of detection of 2.8 × 10−7 M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc–MWCNTs modified surface. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2013.10.023
- Full Text: false
- Authors: Nyoni, Stephen , Mugadza, Tawanda , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7308 , http://hdl.handle.net/10962/d1020385
- Description: Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)–cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc–MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 × 105 M−1 s−1, apparent electron transfer rate constant of 0.073 cm s−1, and a limit of detection of 2.8 × 10−7 M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc–MWCNTs modified surface. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2013.10.023
- Full Text: false
Improved triplet state parameters for indium octacarboxy phthalocyanines when conjugated to quantum dots and magnetite nanoparticles
- Tshangana, Charmaine, Nyokong, Tebello
- Authors: Tshangana, Charmaine , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7252 , http://hdl.handle.net/10962/d1020260
- Description: Fe3O4 magnetic nanoparticles (MNPs) and glutathione (GSH) capped CdSe@ZnS quantum dots (QDs) were separately coordinated to indium octacarboxy phthalocyanine (InPc(COOH)8) to form ClInPc(COOH)8–MNPs and ClInPc(COOH)8–GSH–CdSe@ZnS, respectively. The photophysical parameters (triplet state and fluorescence quantum yields and lifetimes) were determined for the conjugates. The triplet quantum yields increased from ΦT = 0.49 for InPc(COOH)8 alone to ΦT = 0.61 and 0.56 for InPc(COOH)8 in the conjugates: ClInPc(COOH)8–MNPs and ClInPc(COOH)8–GSH–CdSe@ZnS, respectively. The lifetimes also became longer for the conjugates compared to Pc alone. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2015.02.040
- Full Text: false
- Authors: Tshangana, Charmaine , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7252 , http://hdl.handle.net/10962/d1020260
- Description: Fe3O4 magnetic nanoparticles (MNPs) and glutathione (GSH) capped CdSe@ZnS quantum dots (QDs) were separately coordinated to indium octacarboxy phthalocyanine (InPc(COOH)8) to form ClInPc(COOH)8–MNPs and ClInPc(COOH)8–GSH–CdSe@ZnS, respectively. The photophysical parameters (triplet state and fluorescence quantum yields and lifetimes) were determined for the conjugates. The triplet quantum yields increased from ΦT = 0.49 for InPc(COOH)8 alone to ΦT = 0.61 and 0.56 for InPc(COOH)8 in the conjugates: ClInPc(COOH)8–MNPs and ClInPc(COOH)8–GSH–CdSe@ZnS, respectively. The lifetimes also became longer for the conjugates compared to Pc alone. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2015.02.040
- Full Text: false
Influence of nanoparticle materials on the photophysical behavior of phthalocyanines
- Nyokong, Tebello, Antunes, Edith M
- Authors: Nyokong, Tebello , Antunes, Edith M
- Language: English
- Type: Article
- Identifier: vital:7327 , http://hdl.handle.net/10962/d1020577
- Description: This review presents recent data on the photophysical behavior of phthalocyanines when conjugated to quantum dots, gold and magnetic nanoparticles. In some cases such conjugates offer the possibility of being used in “combination therapy”, where two or more substances may be used for treating one disease. The review focuses on the effect that the presence of nanoparticles has on the excited and triplet state parameters of the phthalocyanines. Five tables listing these parameters are presented. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2013.03.016
- Full Text: false
- Authors: Nyokong, Tebello , Antunes, Edith M
- Language: English
- Type: Article
- Identifier: vital:7327 , http://hdl.handle.net/10962/d1020577
- Description: This review presents recent data on the photophysical behavior of phthalocyanines when conjugated to quantum dots, gold and magnetic nanoparticles. In some cases such conjugates offer the possibility of being used in “combination therapy”, where two or more substances may be used for treating one disease. The review focuses on the effect that the presence of nanoparticles has on the excited and triplet state parameters of the phthalocyanines. Five tables listing these parameters are presented. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2013.03.016
- Full Text: false
Internal Memo re staff address 1976
- Authors: Henderson, Derek Scott
- Subjects: Rhodes University
- Language: English
- Type: Text
- Identifier: vital:7341 , http://hdl.handle.net/10962/d1017070
- Full Text:
- Authors: Henderson, Derek Scott
- Subjects: Rhodes University
- Language: English
- Type: Text
- Identifier: vital:7341 , http://hdl.handle.net/10962/d1017070
- Full Text:
Iodine-Doped Cobalt Phthalocyanine Supported on Multiwalled Carbon Nanotubes for Electrocatalysis of Oxygen Reduction Reaction
- Nyoni, Stephen, Mashazi, Philani N, Nyokong, Tebello
- Authors: Nyoni, Stephen , Mashazi, Philani N , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7242 , http://hdl.handle.net/10962/d1020246
- Description: 4-(4,6-Diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II) (CoPyPc) was iodine doped, and its electrocatalytic properties explored. Physical characterization techniques such as UV-vis, X-ray photoelectron, electron paramagnetic resonance and infra-red spectroscopy were used. Cyclic voltammetry, electrochemical impedance spectroscopy and rotating disk electrode were used for electrochemical characterization of electrodes modified with the prepared phthalocyanine and its nanocomposites. The electrocatalytic effect of a new iodine-doped cobalt phthalocyanine derivative supported on multiwalled carbon nanotubes was then investigated towards oxygen reduction reaction. The electrocatalytic activity of the iodine-doped cobalt phthalocyanine was found to be superior in terms of current over the undoped phthalocyanine nanocomposite. , Original publication is available at http://dx.doi.org/10.1002/elan.201400499
- Full Text: false
- Authors: Nyoni, Stephen , Mashazi, Philani N , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7242 , http://hdl.handle.net/10962/d1020246
- Description: 4-(4,6-Diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II) (CoPyPc) was iodine doped, and its electrocatalytic properties explored. Physical characterization techniques such as UV-vis, X-ray photoelectron, electron paramagnetic resonance and infra-red spectroscopy were used. Cyclic voltammetry, electrochemical impedance spectroscopy and rotating disk electrode were used for electrochemical characterization of electrodes modified with the prepared phthalocyanine and its nanocomposites. The electrocatalytic effect of a new iodine-doped cobalt phthalocyanine derivative supported on multiwalled carbon nanotubes was then investigated towards oxygen reduction reaction. The electrocatalytic activity of the iodine-doped cobalt phthalocyanine was found to be superior in terms of current over the undoped phthalocyanine nanocomposite. , Original publication is available at http://dx.doi.org/10.1002/elan.201400499
- Full Text: false
Kingswood College Speech Day address, 3 October 1977
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7358 , http://hdl.handle.net/10962/d1017087
- Full Text:
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7358 , http://hdl.handle.net/10962/d1017087
- Full Text:
Life-giving light
- Authors: Burnett, Mary
- Language: English
- Type: Article
- Identifier: vital:7204 , http://hdl.handle.net/10962/d1006403
- Description: Professor Tebello Nyokong of the Department of Chemistry, at Rhodes University, Grahamstown, is collaborating with Professor David Phillips of the Imperial College, London, as part of the Atlantic Alliance which also involves Emory University, Atlanta and the Georgia Institute of Technology, both in Atlanta, SA.
- Full Text:
- Authors: Burnett, Mary
- Language: English
- Type: Article
- Identifier: vital:7204 , http://hdl.handle.net/10962/d1006403
- Description: Professor Tebello Nyokong of the Department of Chemistry, at Rhodes University, Grahamstown, is collaborating with Professor David Phillips of the Imperial College, London, as part of the Atlantic Alliance which also involves Emory University, Atlanta and the Georgia Institute of Technology, both in Atlanta, SA.
- Full Text:
Message from the Vice-Chancellor
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7387 , http://hdl.handle.net/10962/d1017276
- Full Text:
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7387 , http://hdl.handle.net/10962/d1017276
- Full Text:
Message from the Vice-Chancellor
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7388 , http://hdl.handle.net/10962/d1017277
- Full Text:
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7388 , http://hdl.handle.net/10962/d1017277
- Full Text:
Metalworkers! Engineer your future! VOTE ANC!
- NUMSA
- Authors: NUMSA
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110650 , vital:33318
- Description: NUMSA as part of COSATU has helped draw up the ANC’s Reconstruction and Development Programme. It is our plan. It is the ANC’s plan. It is a plan to: • create jobs • build houses • provide basic services • improve education and training • get rid of discrimination • get the economy growing • put an end to violence • bring democracy to all in society. Comrades, we need a strong new government to get rid of the problems apartheid has left us. If we don’t vote for a strong party, the same people that control us now - the big bosses like Anglo American, Barlow Rand - will still control us. Workers will still suffer.
- Full Text:
- Authors: NUMSA
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110650 , vital:33318
- Description: NUMSA as part of COSATU has helped draw up the ANC’s Reconstruction and Development Programme. It is our plan. It is the ANC’s plan. It is a plan to: • create jobs • build houses • provide basic services • improve education and training • get rid of discrimination • get the economy growing • put an end to violence • bring democracy to all in society. Comrades, we need a strong new government to get rid of the problems apartheid has left us. If we don’t vote for a strong party, the same people that control us now - the big bosses like Anglo American, Barlow Rand - will still control us. Workers will still suffer.
- Full Text:
Moving forward
- FEDUSA
- Authors: FEDUSA
- Subjects: FEDUSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175625 , vital:42600
- Description: The democratic South Africa was birthed through negotiation and dialogue, and a range of socio-economic policy matters continue to be determined on this basis. Social dialogue that focuses on policy, legislation and generally advancing the best interests of society takes place between organised labour, business and government on regular basis in a range of statutory and non-statutory tripartite forums.
- Full Text:
- Authors: FEDUSA
- Subjects: FEDUSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175625 , vital:42600
- Description: The democratic South Africa was birthed through negotiation and dialogue, and a range of socio-economic policy matters continue to be determined on this basis. Social dialogue that focuses on policy, legislation and generally advancing the best interests of society takes place between organised labour, business and government on regular basis in a range of statutory and non-statutory tripartite forums.
- Full Text:
Nanosecond nonlinear optical limiting properties of new trinuclear lanthanide phthalocyanines in solution and as thin films
- Sekhosana, Kutloano Edward, Amuhaya, Edith, Nyokong, Tebello
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7267 , http://hdl.handle.net/10962/d1020276
- Description: 2,4,6-Tris[3-thio-9,10,16,17,23,24-hexa(4-tertbutylphenoxy) phthalocyaninato ytterbium (III) chloride]-s-triazin (3) and its lutetium counterpart (4) were synthesized. The nonlinear optical behavior of 3 and 4 were characterized in solution and when embedded in polymer as thin films. Thin films of complexes 3 and 4 in poly(bisphenol A carbonate) showed improved nonlinear optical properties when compared to solution. Complex 3 showed a lower threshold for optical limiting intensity (Ilim) than complex 4, and for phthalocyanines in general. Ilim values were even lower in films compared to solutions. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.08.047
- Full Text: false
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7267 , http://hdl.handle.net/10962/d1020276
- Description: 2,4,6-Tris[3-thio-9,10,16,17,23,24-hexa(4-tertbutylphenoxy) phthalocyaninato ytterbium (III) chloride]-s-triazin (3) and its lutetium counterpart (4) were synthesized. The nonlinear optical behavior of 3 and 4 were characterized in solution and when embedded in polymer as thin films. Thin films of complexes 3 and 4 in poly(bisphenol A carbonate) showed improved nonlinear optical properties when compared to solution. Complex 3 showed a lower threshold for optical limiting intensity (Ilim) than complex 4, and for phthalocyanines in general. Ilim values were even lower in films compared to solutions. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.08.047
- Full Text: false
Nonlinear optical behaviour of indium-phthalocyanine tethered to magnetite or silica nanoparticles
- Sanusi, Kayode, Stone, Justin M., Nyokong, Tebello
- Authors: Sanusi, Kayode , Stone, Justin M. , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7259 , http://hdl.handle.net/10962/d1020268
- Description: Nonlinear absorption and optical limiting properties of indium phthalocyanine (complex 1) tethered to magnetite (SiMNP-1) or silica (SiNP-1) nanoparticles have been investigated using 10 ns pulses at 532 nm laser excitation. The optical limiting behaviours of the nanocomposites and the bare phthalocyanine are compared. Investigation of the triplet state dynamics revealed highly efficient triplet state absorption in the SiMNP-1 dyad. A large nonlinear absorption (βeff) that increased with decrease in the peak input fluence was observed for SiMNP-1. The SiNP-1 composite showed a slight increase in βeff with decreasing peak input fluence. The nonlinear optical data obtained for the SiNP-1 are within the same range of those of the indium phthalocyanine alone. The nanosecond nonlinear absorption and the optical limiting of the nanocomposites are shown to be dominated by a strong excited state absorption from a two-photon pumped state. Nonlinear scattering effects and strong excited state absorption from a two-photon pumped state account for the enhanced optical limiting behaviour of SiMNP-1 relative to the phthalocyanine alone. , Original publication is available at http://dx.doi.org/10.1039/C4NJ01619J
- Full Text: false
- Authors: Sanusi, Kayode , Stone, Justin M. , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7259 , http://hdl.handle.net/10962/d1020268
- Description: Nonlinear absorption and optical limiting properties of indium phthalocyanine (complex 1) tethered to magnetite (SiMNP-1) or silica (SiNP-1) nanoparticles have been investigated using 10 ns pulses at 532 nm laser excitation. The optical limiting behaviours of the nanocomposites and the bare phthalocyanine are compared. Investigation of the triplet state dynamics revealed highly efficient triplet state absorption in the SiMNP-1 dyad. A large nonlinear absorption (βeff) that increased with decrease in the peak input fluence was observed for SiMNP-1. The SiNP-1 composite showed a slight increase in βeff with decreasing peak input fluence. The nonlinear optical data obtained for the SiNP-1 are within the same range of those of the indium phthalocyanine alone. The nanosecond nonlinear absorption and the optical limiting of the nanocomposites are shown to be dominated by a strong excited state absorption from a two-photon pumped state. Nonlinear scattering effects and strong excited state absorption from a two-photon pumped state account for the enhanced optical limiting behaviour of SiMNP-1 relative to the phthalocyanine alone. , Original publication is available at http://dx.doi.org/10.1039/C4NJ01619J
- Full Text: false
Novel, soluble, FluXoro functional substituted zinc phthalocyanines; synthesis, characterization and photophysicochemical properties
- Erdoğmuş, Ali, Nyokong, Tebello
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7235 , http://hdl.handle.net/10962/d1019686
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041 , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2010.01.001
- Full Text: false
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7235 , http://hdl.handle.net/10962/d1019686
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041 , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2010.01.001
- Full Text: false