A new aromatic amino acid based organogel for oil spill recovery (original) (raw)
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Chemical Physics Letters, 2013
We report gelation behavior of a series of N-acyl-b-alanine (C n -b-Ala) gelators in a variety of organic liquids. The effect of alkyl chain length was studied to elucidate gelation mechanism. The gelation behavior of the C n -b-Ala gelators was compared with that of corresponding N-acyl-L-alanine (C n -L-Ala) derivatives. Unlike C n -L-Ala the C n -b-Ala gelators failed to gel aliphatic hydrocarbons and exhibit phase-selective gelation in the presence of water. The gelation ability of C n -b-Ala was observed to be poorer than C n -L-Ala gelators. Also C n -b-Ala organogels are thermally less stable, but they are observed to have higher mechanical strength than C n -L-Ala organogels.
ChemPhysChem, 2019
To investigate the role of the capping group in the solution and solid-state self-assembly of short peptide amphiphiles, dialanine and diphenylalanine have been linked via the N-terminus to a benzene (phenyl) and 3-naphthyl capping groups using three different methylene linkers; (CH 2)n, n = 0-4 for the benezene and 0, 1 and 2 for the naphthalene capping group). Atomic force microscopy (AFM), oscillatory rheology, circular dichroism (CD) and IR analysis have been employed to understand the properties of these peptidebased hydrogels. Several X-ray structures of these short peptide gelators give useful conformational information regarding packing. A comparison of these solid state structures with their gel state properties yielded greater insights into the process of self-assembly in short peptide gelators, particularly in terms of the important role of C•••H interactions appear to play in determining if a short aromatic peptide does form a gel or not.
Water-Induced Physical Gelation of Organic Solvents by N-(n-Alkylcarbamoyl)-l-alanine Amphiphiles
2011
Low-molecular-weight organogelators (LMOGs) have received considerable attention over recent decades because they exhibit interesting self-assembly phenomena, forming threedimensional (3-D) networks. The interest in this area is driven by their unique supramolecular architectures and wide-ranging applications in industrial fields including drug delivery, tissue engineering, synthesis of nanomaterials and devices, sensing and soft lithography. The self-assembly of LMOGs is often driven by one or more noncovalent forces, such as dipolar interaction, van der Waals forces, hydrogen-bonding (Hbonding), and metal-coordination bonds. The self-assembly leads spontaneously to formation of one-dimensional (1-D) aggregates, which either by physical cross-linking or by entanglement produce 3-D network structures that entrap and immobilize a large volume of solvent in the compartments of selfassembled fibrillar networks (SAFINs) having a large solidliquid interface area by surface tension and ca...
Synthesis and Structure–Property Relationships of Amphiphilic Organogelators
Chemistry - A European Journal, 2007
A series of low-molecular-weight amphiphilic molecules was synthesized and investigated for their ability to gel organic solvents. These amphiphilic molecules are composed of a head-group moiety capable of forming intermolecular associations through hydrogen bonds and n-alkyl chains of various lengths. This paper describes the continuation of recently published work, in which this class of gelators was presented for the first time. Here, the focus addresses systematically three different structural variations of the head-group moiety: 1) the rigidity, 2) the type and strength of the hydrogen-bond-forming units, and 3) the reduction of the intermolecular interaction by incorporating a lateral substituent. The gelation behavior was investigated in p-xylene and in several polar solvents. The aim was to establish structure-property relationships and to provide organogelators capable of forming gels at low concentrations with adjustable sol-gel transition temperatures and good optical quality. For some individual compounds of the series this property profile was achieved. For the investigated solvents, with particular compounds, sol-gel transition temperatures above 100 degrees C with a reasonable concentration of gelator are obtainable.
Self-Assembly and Hydrogelation of Peptide Amphiphiles
MAKARA of Science Series, 2012
Seven peptide amphiphiles were successfully synthesized using solid phase peptide synthesis method. Peptide amphiphiles were characterized using Matrix-assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometer (MALDI-TOF MS). Atomic force microscopy (AFM) study showed that peptide amphiphiles having glycine, valine, or proline as linker, self-assembled into 100-200 nm nanofibers structure. According to our research, both peptide amphiphile with positive and negative charges bear similar self-assembly properties. Peptide amphiphile also showed its capability as low molecular weight gelator (LMWG). Peptide amphiphiles bearing C-16 and C-12 as alkyl showed better hydrogelation properties than C-8 alkyl. Five out of seven peptide amphiphiles have minimum gelation concentration (MGC) lower than 1% (w/v).
Biomimetic Amphiphiles: Properties and Potential Use
Biosurfactants, 2010
S urfactants are the amphiphilic molecules that tend to alter the interfacial and surface tension. The fundamental property related to the structure of surfactant molecules is their self-aggregation resulting in the formation of association colloids. Apart from the packing of these molecules into closed structures, the structural network also results in formation of extended bilayers, which are thermodynamically stable and lead to existence of biological membranes and vesicles. From biological point of view the development of new knowledge and techniques in the area of vesicles, bilayers and multiplayer membranes and their polymerizable analogue provide new opportunities for research in the respective area. 'Green Surfactants' or the biologically compatible surfactants are in demand to replace some of the existing surfactants and thereby reduce the environmental impact, in general caused by classic surfactants. In this context, the term 'natural surfactants or biosurfactants' is often used to indicate the natural origin of the surfactant molecules. Most important aspect of biosurfactants is their environmental acceptability, because they are readily biodegradable and have low toxicity than synthetic surfactants. Some of the major applications of biosurfactants in pollution and environmental control are microbial enhanced oil recovery, hydrocarbon degradation, hexa-chloro cyclohexane (HCH) degradation and heavy-metal removal from contaminated soil. In this chapter, we tried to make a hierarchy from vital surfactant molecules toward understanding their behavioral aspects and application potential thereby ending into the higher class of broad spectrum 'biosurfactants'. Pertaining to the budding promise offered by these molecules, the selection of the type and size of each structural moiety enables a delicate balance between surface activity and biological function and this represents the most effective approach of harnessing the power of molecular self-assembly.