https://commons.ru.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:45268 Wed 16 Mar 2022 10:18:30 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:26996 Wed 12 May 2021 22:53:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29926 Wed 12 May 2021 19:50:04 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34529 Wed 12 May 2021 19:30:43 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29928 Wed 12 May 2021 19:14:28 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29116 Wed 12 May 2021 19:14:06 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29118 Wed 12 May 2021 18:23:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29122 90% cell survival. The photodynamic activity of water insoluble porphyrins improved when encapsulated into the micelles. Novel asymmetrical phthalocyanines were also synthesised for nonlinear optics (NLO) studies in solution and thin films.]]> Wed 12 May 2021 16:05:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41337 Wed 12 May 2021 15:02:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42174 Wed 12 May 2021 15:00:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41489 50% cell viability) at concentrations ≤100 μg/mL, however the conjugates showed < 45% cell viability at concentrations ≤ 100 μg/mL, probably due to the small micellar size and EPR effect. The findings from this work show the importance of incorporating photosensitizers such as phthalocyanines into Pluronic polymers micelles and making them water soluble and ultimately improving their photodynamic effect.]]> Wed 12 May 2021 14:58:28 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41377 Wed 12 May 2021 14:34:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42052 Wed 12 May 2021 14:30:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41328 Wed 12 May 2021 14:19:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41163 Wed 12 May 2021 13:49:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42108 3.76 × 10 − 10 ( 4a ) > 3.52 × 10 − 10 ( 4c ) > 2.29 × 10 − 10 ( 3c ) > 1.68 × 10 − 10 ( 3a ) > 1.65 × 10 − 10 ( 3b ) mW - 1 . The 휷 values trend of synthesized Pc complexes show that the asymmetrical A 3 B type metal free, cobalt and zinc Pc complexes ( 4a , 4b and 4c ) have larger 휷 values as compared to the octa - substituted symmetrical metal free, cobalt and zinc Pc complexes ( 3a , 3b and 3c ) which is attributed to the low symmetry of the Pc complexes. The five - level model rate equations were used to determine the two photon absorption, excited state absorption and ground state absorption cross sections of the synthesized complexes. The z inc A 3 B type asymmetrical Pc complexes gave the largest two photon absorption and 휎 푒 / 휎 푔 ratio values. This Pc complex could be used in future work to enhance the nonlinear response further by introducing nanomaterials and converting the Pc complex to a binuclear Pc. This work also reports on the density functional theory (DFT) calculations o f dipolar/octupolar contributions in order to study the first order hyperpolarizability of the synthesized Pc complexes.]]> Wed 12 May 2021 13:45:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57240 Tue 25 Oct 2022 12:53:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28695 CoTPrOPhOPc > MnTPrOPhOPc. According to the trend observed, the H2TPrOPhOPc was an excellent nonlinear optical limiter when compared to the CoTPrOPhOPc and MnTPrOPhOPc. All the investigated complexes exhibited optical limiting properties comparable to the phthalocyanine complexes reported in the literature. The MTPrOPhOPc complexes were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. For the electrocatalytic studies, the synthesized complexes were immobilized onto gold electrode surfaces pre-functionalized with phenylazide (Au-PAz) monolayer. Copper (I) catalyzed alkynyl-azide cycloaddition reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs modified gold surfaces (Au-PAz-MTPrOPhOPc) exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and surface characterisation of the functionalised gold electrode surfaces confirmed the presence of the MTPrOPhOPcs and their electroanalysis was excellent towards electrocatalytic reduction of H2O2, with the limit of detection (LoD) and limit of quantification (LoQ) in the ^M range. The electrocatalytic reduction peaks for H2O2 were observed at -0.37 V for Au-PAz-MnTPrOPhOPc and -0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-MnTPrOPhOPc and Au- PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution.]]> Thu 20 Apr 2023 09:37:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45021 1.21×10−32(C4h) > 1.05×10−32 (C2v) esu, respectively, in chloroform. Symmetry was seen to have an effect on the observed reverse saturable absorption (RSA) response. Based on the five level model rate equation nonlinear fit of the RSA response curves and Real Time Time Dependant Density Functional Theory (RT-TDDFT) results, the singlet excited state population dynamics was found to play a significant role in producing the observed Im[γ] trend.]]> Thu 17 Feb 2022 15:40:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29119 Thu 13 May 2021 16:04:33 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:31404 Thu 13 May 2021 12:43:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30589 50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.]]> Thu 13 May 2021 08:10:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:35406 Thu 13 May 2021 06:50:34 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29121 Thu 13 May 2021 01:46:43 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27821 Thu 13 May 2021 01:17:53 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42772 Sun 14 Nov 2021 09:23:22 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57238 Mon 24 Oct 2022 15:47:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:44750 22% cell viability at concentrations ≤ 50 μg/mL relative to conjugates with <22% cell viability at concentrations ≤ 50 μg/mL. There was no direct relationship between PDT and singlet oxygen quantum yields. Nonlinear optical characteristics of complexes was improved upon conjugation of DNDs. Absorbance, input energy, percentage loading, central metal, substituent of Pc and nature of interaction (covalent, noncovalent) are amongst some of the factors that influence nonlinear absorption properties of materials used in this study. All materials followed reverse saturable absorption through two photon absorption mechanism at the excitation wavelength of 532 nm. Aggregates reduce excited state lifetime and Beff under high concentrations/absorbance. A direct relationship between absorbance and Beff of DNDs nanoconjugated systems at low concentrations result in increased optical limiting characteristics of materials. The findings from this work show the importance of linking (nonlinear optics and photodynamic therapy) and doping (photodynamic therapy) photosensitisers such as phthalocyanines and sometimes boron dipyrromethenes onto carbon based nanoparticles for the enhanced characteristics in variable applications.]]> Mon 15 Nov 2021 16:13:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:50035 Mon 10 Oct 2022 08:41:01 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27038 Fri 17 Sep 2021 10:11:50 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65804 S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-Vis spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO-1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states.]]> Fri 17 May 2024 16:29:44 SAST ]]>