41. Covalent polymer thin films for biosensor applicationsTina Skorjanc, Andraž Mavrič, Mads Nybo Sorensen, Gregor Mali, Changzhu Wu, Matjaž Valant, 2022, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: bacteria, sensing, electrochemical impedance spectroscopy, electrophoresis, electrode preparation, Menshutkin reaction
Objavljeno v RUNG: 26.09.2022; Ogledov: 1189; Prenosov: 0
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42. Deposition of porphyrin thin films by electrophoresisAndraž Mavrič, Tina Škorjanc, Mads Nybo Sørensen, Changzhu Wu, Matjaž Valant, 2022, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Porphyrins are heterocyclic macrocycles consisting of interconnected pyrrole subunits acting as ligands for metal ions. Metallised metalloporphyrins naturally occur as cofactors in a series of enzymes, acting as active sites for biochemical transformations. Mimicking nature, a variety of functionalized porphyrins have been prepared for different catalytic purposes [1]. These organometallic complexes have isolated metal centers in tailored coordination environments to drive catalytic reactions in homogeneous solutions. The activity and selectivity of isolated metal ions acting as single-atom catalysts are defined by the coordination environment.
Depending on the porphyrin structure, the solubility of these macrocycles and their processability in solutions can be altered. While such adjustments to the structure might ease the processability, the catalytic properties might also be altered. Because homogenous catalysis presents challenges with the separation and recyclability of the catalyst, it is common to fix metalloporphyrins into molecular organic frameworks or deposit them onto a substrate. Commonly used deposition techniques face several challenges. For instance, thermal evaporation can cause partial or complete degradation of some thermally-labile functional groups attached to the porphyrins. Similarly, spin coating commonly results in an uneven thickness and uneven morphology of the deposited films.
To overcome these difficulties, we present an alternative method for the deposition of porphyrin thin films that is suitable for a wide range of functionalized porphyrins. The electrophoresis can force the molecules to deposit on a conductive substrate such as a metal foil or transparent conductive oxide by applying the electric field generated by a DC power supply. The film thickness can be precisely controlled by changing the voltage value, deposition time, or solution concentration using even a small amount of material [2, 3]. Six different functionalized porphyrin molecules have been successfully deposited onto the copper foil substrate by optimizing key parameters, including applied electric field, the duration of electrophoresis, the size of the copper electrodes, and solvent polarity. To demonstrate the generality of our approach, we have selected a broad range of porphyrins that incorporate the following functional groups: phenyl rings, carboxylic acids, pyridyl rings, methyl benzyl ethers, methyl benzoyl esters, and cobalt (II) metalized macrocycle. The impact of this study extends above catalysis to various applications of porphyrins thin films on conductive substrates such as optoelectronics and sensors.
Ključne besede: porphyrin, thin film, electrophoresis
Objavljeno v RUNG: 26.09.2022; Ogledov: 1116; Prenosov: 0
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43. Covalent Organic Framework Based on Azacalix[4]arene for the Efficient Capture of Dialysis Waste ProductsTina Škorjanc, Dinesh Shetty, Felipe Gándara, Pascal Simon, Nawavi Naleem, Salma Abubakar, Liaqat Ali, Abdul Khayum Mohammed, Jesus Raya, Serdal Kirmizialtin, 2022, izvirni znanstveni članek Ključne besede: azacalixarene, covalent organic frameworks, dialysis, uric acid, creatinine, adsorption
Objavljeno v RUNG: 08.09.2022; Ogledov: 1539; Prenosov: 0
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44. Polythiacalixarene-embedded gold nanoparticles for visible-light-driven photocatalytic CO [sub] 2 reductionTina Škorjanc, Kamal Khaja Mohaideen, Ayesha Alkhoori, Gregor Mali, Abdul Khayum Mohammed, Zouhair Asfari, Kyriaki Polychronopoulou, Blaž Likozar, Ali Trabolsi, Dinesh Shetty, 2022, izvirni znanstveni članek Ključne besede: Gold, Materials, Metal nanoparticles, Photocatalysis, Polymers
Objavljeno v RUNG: 13.07.2022; Ogledov: 1452; Prenosov: 0
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46. Covalent Organic Polymers and Frameworks for Fluorescence-Based SensorsTina Škorjanc, Dinesh Shetty, Matjaž Valant, 2021, pregledni znanstveni članek Ključne besede: fluorescence, sensors, covalent organic polymers, covalent organic frameworks, quenching, ions, explosives
Objavljeno v RUNG: 05.05.2021; Ogledov: 2273; Prenosov: 221
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47. Porous polycalix[n]arenes as environmental pollutant removersSalma Abubakar, Tina Škorjanc, Dinesh Shetty, Ali Trabolsi, 2021, pregledni znanstveni članek Opis: A new and innovative class of calixarene-based polymers emerged as adsorbents for a variety of compounds and ions in solution and vapor media. These materials take advantage of the modifiable rims and hydrophobic cavities of the calixarene monomers, in addition to the porous nature of the polymeric matrix. With main-chain calixarenes’ function as supramolecular hosts and the polymers’ high surface areas, polycalixarenes can effectively encapsulate target analytes. This feature is particularly useful for environmental remediation as dangerous and toxic molecules reversibly bind to the macrocyclic cavity, which facilitates their removal and enables repeated use of the polymeric sorbent. This Spotlight touches on the unique characteristics of the calixarene monomers and discusses the synthetic methods of our reported calixarene-based porous polymers, including Sonogashira–Hagihara coupling, and diazo and imine bond formation. It then discusses the promising applications of these materials in adsorbing dyes, micropollutants, iodine, mercury, paraquat, and perfluorooctanoic acid (PFOA) from water. In most cases, these reports cover materials that outperform others in terms of recyclability, rates of adsorption, or uptake capacities of specific pollutants. Finally, this Spotlight addresses the current challenges and future aspects of utilizing porous polymers in pollution treatment.
Ključne besede: calixarene, polycalixarenes, porous polymers, pollutant removal, water purification
Objavljeno v RUNG: 09.04.2021; Ogledov: 2247; Prenosov: 0
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48. Pollutant removal with organic macrocycle-based covalent organic polymers and frameworksTina Škorjanc, Dinesh Shetty, Ali Trabolsi, 2021, pregledni znanstveni članek Opis: Air, water, and soil pollution devastate countless ecosystems and deteriorate human health. Adsorption has commonly been used as a pollutant removal technique, but ongoing materials science research is still searching for more efficient, cheaper, and scalable sorbent materials. Herein, we discuss the synthesis and pollutant-capturing abilities of covalent polymeric structures, including covalent organic polymers and covalent organic frameworks that contain organic macrocycles in the backbone of their structures. These organic macrocycles (cyclodextrin, calixarene, cucurbituril, pillararene, and porphyrin) possess cavities and functional groups that can sequester pollutants by forming supramolecular interactions. The insolubility of these materials prominently aids in their regeneration and recyclability potentials. Following a discussion on the synthetic strategies used in the polymerization of each type of macrocycle, environmental applications of these materials are presented. Here, we focus on the removal of micropollutants, charged species, metal ions, oils and organic solvents, perfluorinated substances, iodine, and volatile organic compounds.
Ključne besede: supramolecular interactions, host-guest chemistry, organic macrocycles, covalent polymers, covalent organic frameworks, environmental remediation, adsorption
Objavljeno v RUNG: 09.04.2021; Ogledov: 2205; Prenosov: 65
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49. Taming the topology of calix[4]arene-based 2D-covalent organic frameworks : interpenetrated vs noninterpenetrated frameworks and their selective removal of cationic dyesBikash Garai, Dinesh Shetty, Tina Škorjanc, Felipe Gándara, Nawavi Naleem, Sabu Varghese, Sudhir Kumar Sharma, Maria Baias, Ramesh Jagannathan, Mark Anthony Olson, 2021, izvirni znanstveni članek Opis: A bowl-shaped calix[4]arene with its exciting host–guest chemistry is a versatile supramolecular building block for the synthesis of distinct coordination cages or metal–organic frameworks. However, its utility in the synthesis of crystalline covalent organic frameworks (COFs) remains challenging, presumably due to its conformational flexibility. Here, we report the synthesis of a periodic 2D extended organic network of calix[4]arenes joined by a linear benzidine linker via dynamic imine bonds. By tuning the interaction among neighboring calixarene units through varying the concentration in the reaction mixture, we show the selective formation of interpenetrated (CX4-BD-1) and non-interpenetrated (CX4-BD-2) frameworks. The cone-shaped calixarene moiety in the structural backbone allows for the interweaving of two neighboring layers in CX4-BD-1, making it a unique example of interpenetrated 2D layers. Due to the high negative surface charge from calixarene units, both COFs have shown high performance in charge-selective dye removal and an exceptional selectivity for cationic dyes irrespective of their molecular size. The charge distribution of the COFs and the resulting selectivity for the cationic dyes were further investigated using computational methods.
Ključne besede: dyes and pigments, covalent organic frameworks, adsorption, layers, chemical structure
Objavljeno v RUNG: 16.03.2021; Ogledov: 2213; Prenosov: 0
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