Mercaptopyridine-substituted indium, zinc, and metal-free phthalocyanines: nonlinear optical studies in solution and on polymer matrices
- Bankole, Owolabi M, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7278 , http://hdl.handle.net/10962/d1020313
- Description: In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl3, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10−9 esu and 7.74 × 10−10 esu) and hyperpolarizability (2.13 × 10−28 and 8.37 × 10−29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1077237
- Full Text: false
- Date Issued: 2015
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7278 , http://hdl.handle.net/10962/d1020313
- Description: In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl3, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10−9 esu and 7.74 × 10−10 esu) and hyperpolarizability (2.13 × 10−28 and 8.37 × 10−29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1077237
- Full Text: false
- Date Issued: 2015
Public foetal images and the regulation of middle-class pregnancy in the online media : a view from South Africa
- Macleod, Catriona I, Howell, Simon
- Authors: Macleod, Catriona I , Howell, Simon
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6307 , http://hdl.handle.net/10962/d1018803 , http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Description: Ultrasonography images and their derivatives have been taken up in a range of ‘public’ spaces, including medical textbooks, the media, anti-abortion material, advertising, the Internet and public health facilities. Feminists have critiqued the personification of the foetus, the bifurcation of the woman’s body and the reduction of the pregnant woman to a disembodied womb. What has received less attention is how these images frequently intersect with race, class, gender and heteronormativity in the creation of idealised and normative understandings of pregnancy. This paper focuses on the discursive positioning of pregnant women as ‘mothers’ and foetuses as ‘babies’ in online media targeted at a South African audience, where race and class continue to intersect in complex ways. We show how the ontologically specific understandings of ‘mummies’ and ‘babies’ emerge through the use of foetal images to construct specific understandings of the ‘ideal’ pregnancy. In the process, pregnant women are made responsible for ensuring that their pregnancy conforms to these ideals, which includes the purchasing of the various goods advertised by the websites. Not only does this point to a commodification of pregnancy, but also serves to reinforce a cultural understanding of White, middle-class pregnancy as constituting the normative ‘correct’ form of pregnancy. , Full text access on publisher website: http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Full Text: false
- Date Issued: 2015
- Authors: Macleod, Catriona I , Howell, Simon
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6307 , http://hdl.handle.net/10962/d1018803 , http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Description: Ultrasonography images and their derivatives have been taken up in a range of ‘public’ spaces, including medical textbooks, the media, anti-abortion material, advertising, the Internet and public health facilities. Feminists have critiqued the personification of the foetus, the bifurcation of the woman’s body and the reduction of the pregnant woman to a disembodied womb. What has received less attention is how these images frequently intersect with race, class, gender and heteronormativity in the creation of idealised and normative understandings of pregnancy. This paper focuses on the discursive positioning of pregnant women as ‘mothers’ and foetuses as ‘babies’ in online media targeted at a South African audience, where race and class continue to intersect in complex ways. We show how the ontologically specific understandings of ‘mummies’ and ‘babies’ emerge through the use of foetal images to construct specific understandings of the ‘ideal’ pregnancy. In the process, pregnant women are made responsible for ensuring that their pregnancy conforms to these ideals, which includes the purchasing of the various goods advertised by the websites. Not only does this point to a commodification of pregnancy, but also serves to reinforce a cultural understanding of White, middle-class pregnancy as constituting the normative ‘correct’ form of pregnancy. , Full text access on publisher website: http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Full Text: false
- Date Issued: 2015
The development of Palladium(II)-specific amine-functionalized silica-based microparticles : adsorption and column separation studies
- Fayemi, Omolola E, Ogunlaja, Adeniyi S, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7270 , http://hdl.handle.net/10962/d1020285
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7270 , http://hdl.handle.net/10962/d1020285
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
The Development of Palladium(II)-Specific Amine-Functionalized Silica-Based Microparticles: Adsorption and Column Separation Studies
- Fayemi, Omolola E, Ogunlaja, Adeniyi S, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7269 , http://hdl.handle.net/10962/d1020278
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7269 , http://hdl.handle.net/10962/d1020278
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
Transformation, job creation and subsidies to creative industries: the case of South Africa’s film and television sector
- Collins, Alan, Snowball, Jeanette D
- Authors: Collins, Alan , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67433 , vital:29087 , https://doi.org/10.1080/10286632.2013.874418
- Description: Pre-print , Many governments have tried to stimulate economic growth via policy on the creative industries. South Africa is no different but additionally has an overarching aim of achieving social and labour market ‘transformation’ to move away from the legacy of the apartheid era. The effectiveness of incentives provided to the film and television sector in South Africa are considered in terms of their stated objectives of job creation, skills and knowledge transfer and the attraction of foreign direct investment. Informed by empirical analysis of incentive scheme data and supplemented by elite interviews with key informants, some specific policy revisions are proposed.
- Full Text:
- Date Issued: 2015
- Authors: Collins, Alan , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67433 , vital:29087 , https://doi.org/10.1080/10286632.2013.874418
- Description: Pre-print , Many governments have tried to stimulate economic growth via policy on the creative industries. South Africa is no different but additionally has an overarching aim of achieving social and labour market ‘transformation’ to move away from the legacy of the apartheid era. The effectiveness of incentives provided to the film and television sector in South Africa are considered in terms of their stated objectives of job creation, skills and knowledge transfer and the attraction of foreign direct investment. Informed by empirical analysis of incentive scheme data and supplemented by elite interviews with key informants, some specific policy revisions are proposed.
- Full Text:
- Date Issued: 2015
Visible light transformation of Rhodamine 6G using tetracarbazole zinc phthalocyanine when embedded in electrospun fibers and in the presence of ZnO and Ag particles
- Khoza, Phindile, Nyokong, Tebello
- Authors: Khoza, Phindile , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7246 , http://hdl.handle.net/10962/d1020251
- Description: Herein, we report the photocatalytic transformation of Rhodamine 6G (Rh 6G) using tetracarbazole zinc phthalocyanine (TCbZnPc) when alone or when conjugated with ZnO macroparticles (ZnOMPs) and silver nanoparticles (AgNPs), represented as TCbZnPc–ZnOMPs and TCbZnPc–AgNPs, respectively. The photocatalysts were supported onto electrospun polystyrene fibers. The efficiency of TCbZnPc was improved by the presence of both ZnOMPs and AgNPs. HPLC equipped with UV–vis was used to study phototransformation products. The mechanism of transformation was via the N-de-ethylation of Rh 6G. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1013944
- Full Text: false
- Date Issued: 2015
- Authors: Khoza, Phindile , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7246 , http://hdl.handle.net/10962/d1020251
- Description: Herein, we report the photocatalytic transformation of Rhodamine 6G (Rh 6G) using tetracarbazole zinc phthalocyanine (TCbZnPc) when alone or when conjugated with ZnO macroparticles (ZnOMPs) and silver nanoparticles (AgNPs), represented as TCbZnPc–ZnOMPs and TCbZnPc–AgNPs, respectively. The photocatalysts were supported onto electrospun polystyrene fibers. The efficiency of TCbZnPc was improved by the presence of both ZnOMPs and AgNPs. HPLC equipped with UV–vis was used to study phototransformation products. The mechanism of transformation was via the N-de-ethylation of Rh 6G. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1013944
- Full Text: false
- Date Issued: 2015
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