Nanostructured materials have many forms. One that has been somewhat neglected until recently is organogels, especially those whose three-dimensional structural networks are based on the self-assembly of low molecular-mass organic gelators (LMOGs). These thermoreversible consist a small amount LMOG and an liquid. Because wide diversity structures molecules known to function as LMOGs dearth direct information concerning how they pack in their gel assemblies, it difficult decipher salient...

This Account presents recent advances in understanding how and why dilute solutions/sols of low-molecular-mass organic gelators (LMOGs) undergo microscopic phase separation to form self-assembled fibrillar networks molecular organogels. Concepts are illustrated structurally at the subnanometer (molecular) several millimeter (bulk) length scales dynamically over time that follow assembly supersaturated into gel phases. Examples include both complicated (ALSmolecules with aromatic, linking,...

A Perspective is presented on the history and current understanding of molecular gels factors that must be considered to characterize them. The abilities most important structural, dynamic, rheological tools available currently provide information necessary follow formation a gel from its initial sol phase then define it at different distance time scales are discussed. Approaches determining priori when molecule will gelate selected liquid, as well possible methodologies for overcoming...

Quantum dots (QDs) offer new and versatile ways to harvest light energy. However, there are few examples involving the utilization of QDs in organic synthesis. Visible-light irradiation CdSe was found result virtually quantitative coupling a variety thiols give disulfides H2 without need for sacrificial reagents or external oxidants. The addition small amounts nickel(II) salts dramatically improved efficiency conversion through facilitating formation hydrogen atoms, thereby leading faster...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLiquid-crystalline solvents as mechanistic probes. Part 37. Novel family of gelators organic fluids and the structure their gelsYih Chyuan Lin, Bechara Kachar, Richard G. WeissCite this: J. Am. Chem. Soc. 1989, 111, 15, 5542–5551Publication Date (Print):July 1, 1989Publication History Published online1 May 2002Published inissue 1 July 1989https://pubs.acs.org/doi/10.1021/ja00197a005https://doi.org/10.1021/ja00197a005research-articleACS...

Duplications of the alimentary tract are unusual congenital anomalies that frequently present a diagnostic as well therapeutic challenge to surgeon. Because these lesions occur so infrequently, they often not suspected until encountered intraoperatively. Due complicated anatomy and common blood supply shared between duplication associated native bowel, appropriate management requires familiarity with clinical characteristics this entity. To better define range patient characteristics,...

Thermoreversible gelation of relatively short n-alkanes and a variety other organic liquids has been accomplished using low concentrations long (chain lengths from 24 to 36 carbon atoms) as gelators. The stability the gels is discussed in terms gelator concentration, temperature, duration time persist without bulk phase separation. Generally, increases with chain length gelator. n-Alkanes are structurally simplest gelators possible their organogels that can be made. Their existence...

Well-structured physical gels, composed of an organic liquid and a small amount gelator molecule like the title compound 1, are known to have microstructures inter-linked fibers. A method is described for determination molecular packing arrangements molecules in fibers, based upon subtracting X-ray powder diffraction pattern neat component from that gel relating difference morphs solid.

The kinetics and mode of nucleation growth fibers by 5α-cholestan-3β-yl N-(2-naphthyl)carbamate (CNC), a low-molecular-mass organogelator (LMOG), in n-octane n-dodecane have been investigated as their sols were transformed isothermally to organogels. has followed detail circular dichroism, fluorescence, small-angle neutron scattering, rheological methods. When treated according Avrami theory, kinetic data from the four methods are self-consistent describe gelation process involving...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochemistry in organized and confining media: a modelRichard G. Weiss, V. Ramamurthy, George S. HammondCite this: Acc. Chem. Res. 1993, 26, 10, 530–536Publication Date (Print):October 1, 1993Publication History Published online1 May 2002Published inissue 1 October 1993https://pubs.acs.org/doi/10.1021/ar00034a003https://doi.org/10.1021/ar00034a003research-articleACS PublicationsRequest reuse permissionsArticle Views707Altmetric-Citations207LEARN...

The works of art and artifacts that constitute our cultural heritage are subject to deterioration, both from internal external factors. Surfaces interact with the environment most prone aging decay; accordingly, soiling is a prime factor in degradation surfaces attendant disfigurement piece. Coatings were originally intended protect or contribute aesthetically an artwork should be removed if they begin have destructive impact on its appearance surface chemistry. Since mid-19th century,...

The kinetics of the isothermal transformation sols, comprised a low molecular-mass organogelator (LMOG) and an organic liquid, to their organogel phases have been followed by circular dichroism (CD), fluorescence, small angle neutron scattering (SANS), rheological methods. thixotropic properties (in sense that severe shearing rest lead reestablishment viscoelasticity) gels examined as well measurements. compositions samples were either 5α-cholestan-3β-yl N-(2-naphthyl) carbamate (CNC) in...

The properties of a series organogels consisting urea or thiourea derivative with one two n-alkyl substitutuents at the nitrogen atoms (a low molecular-mass organogelator (LMOG)) and an organic liquid are described. They include N,N'-dimethylurea, LMOG lowest molecular mass (M(W) 88) we aware of. efficiencies LMOGs, based diversity liquids gelated, minimum amount required for gelation room temperature, temporal thermal stabilities gels formed, have been investigated as function number,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLiquid-crystalline solvents as mechanistic probes. 24. A novel gelator of organic liquids and the properties its gelsYih Chyuan. Lin Richard G. WeissCite this: Macromolecules 1987, 20, 2, 414–417Publication Date (Print):February 1, 1987Publication History Published online1 May 2002Published inissue 1 February 1987https://pubs.acs.org/doi/10.1021/ma00168a031https://doi.org/10.1021/ma00168a031research-articleACS PublicationsRequest reuse...

The self-assembly behavior of a series glucono-appended 1-pyrenesulfonyl derivatives containing α,ω-diaminoalkane spacers (Pn, where n, the number methylene units separating amino groups, is 2, 3, 4, 6, 7, and 8) in v:v tetrahydrofuran (THF):water mixtures examined at room temperature. Pn 2 w/v % concentrations do not dissolve either THF or water However, can be dissolved some THF:water mixtures, they form gels spontaneously other compositions without dissolving completely. liquid has been...

Solvent properties play a central role in mediating the aggregation and self-assembly of molecular gelators their growth into fibers. Numerous attempts have been made to correlate solubility parameters solvents gelation abilities gelators, but comprehensive comparison most important has yet appear. Here, degree which partition coefficients (log P), Henry's law constants (HLC), dipole moments, static relative permittivities (εr), solvatochromic ET(30) parameters, Kamlet–Taft (β, α, π),...

Many small molecules can self-assemble by non-covalent interactions into fibrous networks and thereby induce gelation of organic liquids. However, no capability currently exists to predict whether a molecule in given solvent will form gel, low-viscosity solution (sol), or an insoluble precipitate. Gelation has been recognized as phenomenon that reflects balance between solubility insolubility; however, the distinction these regimes not quantified systematic fashion. In this work, we focus on...

Three rigid and structurally simple heterocyclic stilbene derivatives, (E)-3H,3'H-[1,1'-biisobenzofuranylidene]-3,3'-dione, (E)-3-(3-oxobenzo[c] thiophen-1(3H)-ylidene)isobenzofuran-1(3H)-one, (E)-3H,3'H-[1,1'-bibenzo[c] thiophenylidene]-3,3'-dione, are found to fluoresce in their neat solid phases, from upper (S2 ) lowest (S1 singlet excited states, even at room temperature air. Photophysical studies, single-crystal structures, theoretical calculations indicate that large energy gaps...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructures of Organogels Based upon Cholesteryl 4-(2-Anthryloxy)butanoate, a Highly Efficient Luminescing Gelator: Neutron and X-ray Small-Angle Scattering InvestigationsP. Terech, I. Furman, R. G. WeissCite this: J. Phys. Chem. 1995, 99, 23, 9558–9566Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June...

On the basis of data from a combination X-ray diffraction techniques, BO morph hexatriacontane [H(CH2)36H], low-molecular-mass gelator several classes liquids (including shorter n-alkanes), has been identified unambiguously as molecular packing arrangement within microplatelet units organogel superstructures. In addition, long axes molecules have shown to be perpendicular planes microplatelets by an optical microscopic method.