Supramolecular polymerization: challenges and advantages of various methods in assessing the aggregation mechanism

Vill, Roman; Gülcher, Jochen; Khalatur, Pavel G.; Wintergerst, Pascal; Stoll, Andreas; Mourran, Ahmed; Ziener, Ulrich

doi:10.1039/c8nr08472f

Cited by 9 publications

(9 citation statements)

References 48 publications

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“…The typical crystallographic orientation is observed at the boundary among the nanoparticles. This aggregated process exactly represented the common growth mechanism of OA [20]. Similar OA mechanism took place for the ZnO nanoparticles as the temperature increases (Figure 3D).…”

Section: Influence Of the Reaction Temperaturesupporting

confidence: 67%

pH-Dependent Formation of Oriented Zinc Oxide Nanostructures in the Presence of Tannic Acid

2020

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To crucially comprehend the relaying factors behind the growth mechanism of ZnO nanostructures, the needs to understand the cause of preferences in the enhancement of desired physicochemical properties are essential. The particular oriented attachment (OA) is believed to become the cause of the classical growth pattern of ZnO nanostructures which is mainly controlled by the Ostwald ripening (OR) process. In the present work, the concerns over the systematic changes in size and the morphological surface of ZnO nanostructures upon exposure to tannic acid (TA) prepared by drop-wise method turns the particles to different surface adjustment state. Here, we assessed the TA capping ability and its tendency to influence the OA process of the ZnO nanostructures. The detailed process of the growth-based TA system via transmission electron microscopy (TEM), scanning electron microscopy (SEM), and FFT autocorrelation revealed the pH effect on their physical properties which proved the transition surface properties state of the particles from rough to smooth states due to oriented attachment. For pure ZnO nanostructures, the surface is almost smooth owing to the strong bonding particles which are then changed to coarsened surface structures upon the introduction of TA. Strong surface adsorption of Zn cations and phenol ligands mediated the agglomerated nanocrystals, surprisingly with smaller nanostructures dimension.

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Section: Influence Of the Reaction Temperaturesupporting

confidence: 67%

pH-Dependent Formation of Oriented Zinc Oxide Nanostructures in the Presence of Tannic Acid

2020

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“…In order to determine the nature of an additive and its influence on the chain length of supramolecular systems under kinetic or thermodynamic control, several analytical techniques have to be combined. 83 The two parameters to be determined for analyzing the influence of an additive are the numberaveraged degree of aggregation ϕ agg (the number of monomers in an aggregated state) and the degree of polymerization DP n ¼ X n ¼ M n /M 0 (the number average of monomers in an aggregate). Isodesmic supramolecular systems tend to have high ϕ agg but low DP n , while cooperative systems are usually highly aggregated and show high DP n .…”

Section: How To Experimentally Determine the Effect Of B On Supramolementioning

confidence: 99%

How to Determine the Role of an Additive on the Length of Supramolecular Polymers?

et al. 2020

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In polymer chemistry, modulation of sequence and control over chain length are routinely applied to alter and fine-tune the properties of covalent (co)polymers. For supramolecular polymers, the same principles underlying this control have not been fully elucidated up to this date. Particularly, rational control over molecular weight in dynamic supramolecular polymers is not trivial, especially when a cooperative mechanism is operative. We start this review by summarizing how molecular-weight control has been achieved in seminal examples in the field of supramolecular polymerizations. Following this, we propose to classify the avenues taken to control molecular weights in supramolecular polymerizations. We focus on dynamic cooperative supramolecular polymerization as this is the most challenging in terms of molecular weight control. We use a mass-balance equilibrium model to predict how the nature of the interaction of an additive B with the monomers and supramolecular polymers of component A affects the degree of aggregation and the degree of polymerization. We put forward a classification system that distinguishes between B acting as a chain capper, a sequestrator, a comonomer, or an intercalator. We also highlight the experimental methods applied to probe supramolecular polymerization processes, the type of information they provide in relation to molecular weight and degree of aggregation, and how this can be used to classify the role of B. The guidelines and classification delineated in this review to assess and control molecular weights in supramolecular polymers can serve to reevaluate exciting systems present in current literature and contribute to broaden the understanding of multicomponent systems.

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“…Therefore, the normalized curve of the temperature dependent intensity of the emission has an S‐shape (Figure 5b) [22] . In this case, the dependence of the luminescence maximum on the temperature was used to make the curve.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the normalized curve of the temperature dependent intensity of the emission has an S-shape (Figure 5b). [22] In this case, the dependence of the luminescence maximum on the temperature was used to make the curve. The point of inflection of this line defines the temperature of dissociation of aggregates forming in the solution.…”

Section: Optical Propertiesmentioning

confidence: 99%

“…1 H NMR (CDCl 3 , 250 MHz, δ ppm): 0.07 (s, 6H, AlkÀ SiÀ CH 3 ), 0.17 (d, 6H, J = 2.4 Hz, HÀ SiÀ CH 3 ), 0.62 (m, 2H, J = 8.6 Hz, À SiÀ CH 2 ), 1.71 (m, 2H, À CH 2 À CH 2 À CH 2 À ), 2.80 (t, 2H, J = 7.3 Hz, ThÀ CH 2 À ), 4.68 (m, 1H, J = 5.5 Hz, À SiÀ H), 6.68 (d, 1H, J = 3.7 Hz, ThÀ HÀ CH 2 À ), 6.97-7.05 (overlapped peaks, 4H), 7.15 (dd, 1H, J 1 = 3.7 Hz, J 2 = 1.2 Hz, ThÀ H), 7.195 (dd, 1H, J 1 = 4.9 Hz, J 2 = 1.2 Hz, ThÀ H). 13 1,3-bis[3-(2,2':5',2''-terthien-5-yl)propyl]-1,1,3,3-tetramethyldisiloxane (22). 5-allyl-2,2':5',2''-terthiophene 18 (0.90 g, 3.1 mmol) and compound 20 (1.43 g, 3.1 mmol) was dissolved in toluene (30 mL) under argon, then Karstedt's catalyst (25 mkl) was added.…”

Section: 3-bis[3-(5''-bromo-22':5'2''-terthien-5-yl)propyl]-1133tetra...mentioning

confidence: 99%

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Synthesis and Aggregation Behavior of Novel Linear and Branched Oligothiophene‐Containing Organosilicon Multipods

et al. 2022

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The synthesis of novel oligothiophene‐containing carbosilane‐siloxanes of linear or branched structure with conjugation lengths of 4–7 thiophene rings, flexible aliphatic spacers varying from C3 to C11, and various degrees of branching of end‐capping solubilizing groups is reported. The investigation of their phase behavior by differential scanning calorimetry and polarizing optical microscopy showed that although some of them can form liquid‐crystalline phases, the majority of the linear molecules exhibits a high degree of crystallinity, which decreases with increasing degree of branching. Aggregation studies in dilute solutions in toluene at different temperatures allowed determination of the temperature and concentration dependence of their dissociation. The investigation of thin films prepared from dilute solutions revealed the formation of fibril domains confirming aggregation of the molecules.

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Supramolecular polymerization: challenges and advantages of various methods in assessing the aggregation mechanism

Abstract: Caution must be exercised when evaluating data of supramolecular polymerization at high concentrations and various methods should be employed.

Cited by 9 publications

References 48 publications

pH-Dependent Formation of Oriented Zinc Oxide Nanostructures in the Presence of Tannic Acid

pH-Dependent Formation of Oriented Zinc Oxide Nanostructures in the Presence of Tannic Acid

How to Determine the Role of an Additive on the Length of Supramolecular Polymers?

Synthesis and Aggregation Behavior of Novel Linear and Branched Oligothiophene‐Containing Organosilicon Multipods

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