Evaluation of metallophthalocyanine functionalized photocatalytic asymmetric polymer membranes for pollution control and antimicrobial activity
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi
- Date: 2021
- Subjects: Photosensitizing compounds , Water -- Purification -- Photocatalysis , Phthalocyanines , Polymeric membranes , Porphyrins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/171357 , vital:42052 , 10.21504/10962/171357
- Description: The conceptualisation of photosensitizing water treatment polymer membranes using phthalocyanine based photosensitizers is reported in this thesis. The key to successful preparation of stable photoactive polymer membranes was established as the covalent anchorage of the photosensitizer to a polymer, which was proven by singlet oxygen generation by the membranes without photosensitizer deterioration. Despite this limitation, the covalent linkage-incapable unsubstituted zinc (II) phthalocyanine (complex 2) was applied as a nanoconjugate of graphene quantum dots (2π(GQDs)). 2π(GQDs) was formed through π-π stacking, and was then covalently anchored, as a proof of concept. This concept was also applied to 2-(4-carboxyphenoxy) phthalocyaninato zinc (II) (complex 3) which is capable of covalent linkage but proved to deteriorate the efficiency of singlet oxygen formation with comparison to the covalent conjugates. Singlet oxygen generation by functionalized polymer membranes rendered them photocatalytic in the degradation of organic pollutants and microorganisms in water. Organic pollutant degradation capability was exemplified by 2π(GQDs) and a porphyrin-phthalocyanine heterodyad (complex 10) functionalized membranes (2π(GQDs)-memb and 10-memb respectively), where a MPc loading of approximately 0.139 μmol MPc/g of membrane was able to achieve a 4-chlorophenol degradation rate of 3.77 × 10−6 mol L−1 min−1 in a second order reaction with an initial 4-chlorophenol concentration of 3.24 × 10−4 mol L−1 for 2π(GQDs)-memb as an example. Antibacterial studies against S.aureus using a quaternized MPc and conjugates of silver triangular nanoprisms with zinc (II) and indium (III) MPcs showed note-worthy improvements in photodynamic antimicrobial chemotherapy (PACT) activity in comparison to the unquaternized MPc precursor, and the free zinc and indium MPcs respectively. Functionalization of polymer membranes with these higher activity photosensitizers translated to the formation of potentially superior biological fouling resistant membranes. The use of porphyrin-phthalocyanine polynuclei arrays (complex 10) in polymer membrane functionalization resulted in the use of a wider wavelength range (white light). The findings from this work as a whole, thus presents the potential applicability of phthalocyanine functionalized polymer membranes in water treatment technology.
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- Date Issued: 2021
Emancipatory politics and the Mpondo revolts
- Authors: Bruchhausen, Sarah
- Date: 2017
- Subjects: Pondo Revolt, South Africa, 1960-1963 , South Africa -- History -- 20th century , South Africa -- Politics and government -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5093 , vital:20765
- Description: This thesis aims to offer a revised view of the Mpondo revolts. The central theoretical concept of the thesis is that of emancipatory politics. Drawing predominantly on archival sources the primary concern of the thesis is to expose and interrogate certain aspects of this historical moment of popular politics which can be seen as emancipatory. In particular the notions of egalitarianism and universal human dignity will be analysed in relation to the popular political subjectivities, formations and praxes of the Mpondo revolts. In so doing this thesis attempts to make a meaningful contribution to present day debates concerning alternative theories of human emancipation by showing what emancipatory politics looked like historically and in practise within the context of the Mpondo revolts.
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- Date Issued: 2017
Emotions, social transformation and education
- Authors: Delport, Aletta Catherine
- Date: 2004
- Subjects: Educational sociology -- South Africa , Education -- Philosophy , Emotions (Philosophy)
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11009 , http://hdl.handle.net/10948/318 , Educational sociology -- South Africa , Education -- Philosophy , Emotions (Philosophy)
- Description: This thesis addresses the topic of the education of the emotions in the context of a rapidly transforming South African society. It attempts to reconfigure the conceptual landscape in terms of which we think about rationality, social transformation and education, and contests the intellectual and instrumental prejudice in the currently dominant ways of thinking about education. It reclaims a sense of what it would be to think of education in terms of cultivating humanity, as a key to the profound transformation of the South African society. It argues that the emotions should be relocated in our conception of transformation and education, because without it, education will fail to assist South African society to transform into a society where most people are able to live improved quality lives. The thesis comprises three distinct parts. The first part consists of an account of a particular cognitive theory of the emotions, as developed by Martha Nussbaum in her book, Upheavals of thought. The Intelligence of Emotions (2001). This theory is then applied in Part 2 to examine the complexities of social transformation in South Africa at the more profound, personal level. This investigation is presented as a narrative and comprises the perspectives of the author, who is a white Afrikaner female, who grew up in South Africa in the heyday of Apartheid. In the final part, the concept of ‘education for transformation’ is discussed. It is argued that, in order for education to enhance the social transformation of South Africa, social transformation should be conceived according to a fundamental aspect of Rousseau’s political philosophy, namely that the ideal society comprises two reciprocally related spheres, the political and the personal sphere. Part 3 argues that ‘education for transformation’ should be conceived according to a conception of transformation, which acknowledges this double-layered texture. It further argues that ‘education for transformation’ should primarily be concerned with transformation at the personal level, since, according to Rousseau’s philosophy, this dimension is fundamental to ensuring the stability and legitimacy of the political order. However, built on the main insights of Part 2, this thesis also argues that personal transformation is only possible within a framework of rationality, which acknowledges the emotions as constitutive elements of rationality itself. Essentially, this thesis is about the conception of human being, which should be esteemed as the most fundamental and crucial element of successful social transformation.
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- Date Issued: 2004