Hydrophobicity Control in Adaptive Crystalline Assemblies

Cohen, Erez; Soffer, Yahel; Weissman, Haim; Bendikov, Tatyana; Schilt, Yaelle; Raviv, Uri; Rybtchinski, Boris

doi:10.1002/anie.201801912

Cited by 14 publications

(9 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Small molecules give rise to weaker, less predictable interactions than block copolymers. , Therefore, their utilization in the rational design of complex ordered polymer-like materials is challenging. ,, In this respect, self-assembly in aqueous medium, imposing strong hydrophobic interactions between molecular moieties and enhanced self-sorting, can be advantageous. , For this purpose, we designed a simplified molecular version of common triblock copolymers, − PPF , in which two different hydrophobic molecular units are attached to the termini of a hydrophilic polymer (Figure a) …”

Section: Materials Based On Organic Nanocrystalsmentioning

confidence: 99%

Noncovalent Aqua Materials Based on Perylene Diimides

et al. 2019

Self Cite

View full text Add to dashboard Cite

CONSPECTUS: Most robust functional organic materials are currently based on polymers. These materials exhibit high stability, but once formed they are difficult to modify, adapt to their environment, and recycle. Materials based on small molecules that are held together by noncovalent interactions can offer an alternative to conventional polymer materials for applications that require adaptive and stimuli-responsive features. However, it is challenging to engineer macroscopic noncovalent materials that are sufficiently robust for practical applications. This Account summarizes progress made by our group towards the development of noncovalent "aqua materials" based on well-defined organic molecules. These materials are uniquely assembled in aqueous media, where they harness the strength of hydrophobic and π−π interactions between large aromatic groups to achieve robustness. Despite their high stability, these supramolecular systems can dynamically respond to external stimuli. We discuss design principles, fundamental properties, and applications of two classes of aqua materials: (1) supramolecular gels and (2) nanocrystalline arrays. The materials were characterized by a combination of steady-state and time-resolved spectroscopic techniques, electrical measurements, molecular modeling, and high-resolution microscopic imaging, in particular cryogenic transmission electron microscopy (cryo-TEM) and cryogenic scanning electron microscopy (cryo-SEM). All investigated aqua materials are based on one key building block, perylene diimide (PDI). PDI exhibits remarkably stable intermolecular bonds, together with useful chemical and optoelectronic properties. PDI-based amphiphiles carrying poly(ethylene glycol) (PEG) were designed to form linear supramolecular polymers in aqueous media. These one-dimensional arrays of noncovalently linked molecules can entangle and form three-dimensional supramolecular networks, leading to soft gellike materials. Tuning the strength of interactions between fibers enables dynamic adjustment of viscoelastic properties and functional characteristics. Besides supramolecular gels, we show that simple PDI-based molecules can self-assemble in aqueous medium to form robust organic nanocrystals (ONCs). The mechanical and optoelectronic properties of ONCs are distinctly different from gel-phase materials. ONCs are excellent building blocks for macroscopic free-standing materials that can be used in dry state, unlike hydrogels. Being constructed from small molecules, ONC materials are easy to fabricate and recycle. High thermal robustness, good mechanical properties, and modular design render ONC materials versatile and suitable for a variety of applications. In the future, noncovalent aqua materials can become a sustainable alternative to conventional polymer materials. Examples from our research include stimuli-responsive and recyclable filtration membranes for preparative nanoparticle separation, water purification and catalysis, light-harvesting hydrogels for solar energy conversion, and nanocryst...

show abstract

Section: Materials Based On Organic Nanocrystalsmentioning

confidence: 99%

Noncovalent Aqua Materials Based on Perylene Diimides

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…This understanding is particularly relevant in aqueous media, considering the important implications of amphiphilic systems as mimics of biological systems and their potential applications in various fields, including bioimaging, − photodynamic therapy, and tissue engineering. − However, the understanding gained from molecular design approaches in organic solvents cannot be merely extrapolated to aqueous media, as the competitive binding of hydrogen bonding donors and acceptors with water, as well as hydrophobic interactions, can result in unpredictable self-assembly outcomes. − Typically, control over self-assembly pathways in aqueous media is achieved by exploiting aromatic and hydrophobic interactions as the main driving force, − as they can offer a higher robustness and predictability than hydrogen bonding under these conditions. , Common structural features of most of these examples are poly-/oligoethylene glycol chains, which ensure suitable solubility in aqueous solvent systems. − These solubilizing chains have been observed to undergo folding and chain-enwrapping effects in the molecularly dissolved state − and in self-assembled architectures, , particularly if they are attached to hydrophobic π-scaffolds. These detailed studies have garnered a significant understanding of chain solvation and associated entropically driven and heat-induced self-assembly processes under thermodynamic control. − ,, …”

Section: Introductionmentioning

confidence: 99%

Pathway-Controlled Aqueous Supramolecular Polymerization via Solvent-Dependent Chain Conformation Effects

et al. 2023

View full text Add to dashboard Cite

Solute−solvent interactions play a critical role in multiple fields, including biology, materials science, and (physical) organic, polymer, and supramolecular chemistry. Within the growing field of supramolecular polymer science, these interactions have been recognized as an important driving force for (entropically driven) intermolecular association, particularly in aqueous media. However, to date, solute−solvent effects remain poorly understood in the context of complex self-assembly energy landscapes and pathway complexity. Herein, we unravel the role of solute−solvent interactions in controlling chain conformation effects, allowing energy landscape modulation and pathway selection in aqueous supramolecular polymerization. To this end, we have designed a series of oligo(phenylene ethynylene) (OPE)based bolaamphiphilic Pt(II) complexes OPE2−4 bearing solubilizing triethylene glycol (TEG) chains of equal length on both molecule ends, but a different size of the hydrophobic aromatic scaffold. Strikingly, detailed self-assembly studies in aqueous media disclose a different tendency of the TEG chains to fold back and enwrap the hydrophobic molecular component depending on both the size of the core and the volume fraction of the co-solvent (THF). The relatively small hydrophobic component of OPE2 can be readily shielded by the TEG chains, leading to only one aggregation pathway. In contrast, the decreased capability of the TEG chains to effectively shield larger hydrophobic cores (OPE3 and OPE4) enables different types of solvent quality-dependent conformations (extended, partly back-folded and back-folded), which in turn induce various controllable aggregation pathways with distinct morphologies and mechanisms. Our results shed light on previously underappreciated solvent-dependent chain conformation effects and their role in governing pathway complexity in aqueous media.

show abstract

“…In a purely supramolecular example, aqueous solutions of a telechelic PEG with an α‐PDI and an ω‐perfluorinated alkyl chain were drop‐casted on glass surfaces 118. Aggregation of the perfluorinated units via hydrophobic interactions and PDIs via π–π‐stacking resulted in highly hydrophobic surfaces with enclosed crystalline PEG domains.…”

Section: Aqueous Stimuli‐responsive Materialsmentioning

confidence: 99%

Design Principles for Aqueous Interactive Materials: Lessons from Small Molecules and Stimuli‐Responsive Systems

et al. 2020

View full text Add to dashboard Cite

Interactive materials are at the forefront of current materials research with few examples in the literature. Researchers are inspired by nature to develop materials that can modulate and adapt their behavior in accordance with their surroundings. Stimuli‐responsive systems have been developed over the past decades which, although often described as “smart,” lack the ability to act autonomously. Nevertheless, these systems attract attention on account of the resultant materials' ability to change their properties in a predicable manner. These materials find application in a plethora of areas including drug delivery, artificial muscles, etc. Stimuli‐responsive materials are serving as the precursors for next‐generation interactive materials. Interest in these systems has resulted in a library of well‐developed chemical motifs; however, there is a fundamental gap between stimuli‐responsive and interactive materials. In this perspective, current state‐of‐the‐art stimuli‐responsive materials are outlined with a specific emphasis on aqueous macroscopic interactive materials. Compartmentalization, critical for achieving interactivity, relies on hydrophobic, hydrophilic, supramolecular, and ionic interactions, which are commonly present in aqueous systems and enable complex self‐assembly processes. Relevant examples of aqueous interactive materials that do exist are given, and design principles to realize the next generation of materials with embedded autonomous function are suggested.

show abstract

Hydrophobicity Control in Adaptive Crystalline Assemblies

Cited by 14 publications

References 55 publications

Noncovalent Aqua Materials Based on Perylene Diimides

Noncovalent Aqua Materials Based on Perylene Diimides

Pathway-Controlled Aqueous Supramolecular Polymerization via Solvent-Dependent Chain Conformation Effects

Design Principles for Aqueous Interactive Materials: Lessons from Small Molecules and Stimuli‐Responsive Systems

Contact Info

Product

Resources

About