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In this study, the isotropic magnetorheological elastomer samples are fabricated with and without addition of carbon blacks into the silicon rubber matrix and carbonyl iron particles in the absence of magnetic field. Microscopic and morphological analyses, thermo-gravimetric analysis, MH measurements, thermomechanical analysis, dynamic mechanical analysis, tensile test and magnetorheological test of magnetorheological elastomers are performed to characterize the fabricated magnetorheological elastomers. The experimental results demonstrate that the addition of carbon black improves the mechanical properties of the magnetorheological elastomer. The fabricated magnetorheological elastomers can be used in applications such as adaptive tuned vibration absorbers and vibration reduction in sandwich structures.

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A logically synthesized ortho-phenylenediamine based chloro-methyl disubstituted neutral organic bis-urea receptor L 1 with the aid of three symmetry-independent units encapsulates an unusual triangular [(chloride)3-DMSO] guest assembly (complex 1a) via formation of DMSO + host + salt cocrystals within its trimeric paddle-wheel shaped cavity sealed by three n-TBA cations and exhibits diverse anion binding properties with oxyanions along with the chloride complex of its isomeric bromo-methyl disubstituted bis-urea receptor L 2 . Receptor L 2 and L 1 both form a similar kind of noncapsular 2:2 host–guest assembly in the presence of excess chloride (complex 2a) and acetate (complex 1b) respectively by noncooperative H-bonding interactions of urea groups which are attributed to the effect of meta-functionalization with respect to the adjacent N–H part of the urea moiety, whereas another planar oxyanion carbonate is doubly encapsulated within the tetrameric capsular cavity of L 1 in the solid state (complex 1c). Moreover, receptor L 2 conforms to a similar kind of cation sealed 2:1 host–guest pseudocapsular complex in the presence of larger coordinating anions such as tetrahedral sulfate (complex 2b) and octahedral hexafluorosilicate (complex 2c). 1H NMR titration experiments are also performed using n-TBA/TEA salts of anions to investigate the solution state anion binding behavior of isomeric L 1 and L 2 and corroborate the results obtained in the solid-state studies.

A novel tripodal receptor has been reported as a fluorescent chemosensor for fluoride ions. Moreover, in solid state, seven units of the protonated receptors form a pseudo-capsular cavity to encapsulate two pairs of sulphate anions.

A rationally designed ortho-phenylenediamine based trifluoromethyl meta-disubstituted bis-urea receptor (L) exhibits effective, consistent and systematic binding in its neutral form towards smaller spherical halides (fluoride, chloride, bromide and iodide), and relatively larger planar carbonate and tetrahedral sulphate oxyanions. All the complexes are well characterized both in the solid-state and solution phase. In the presence of excess fluoride anions, the receptor L encapsulates a hydrated cyclic fluoride-water [F(HO)] tetramer inside the n-TBA cation sealed dimeric complementary cavity (complex 1). Whereas excess n-TBA/TEA salts of chloride, bromide and iodide result in unusual (Cl), (Br), and (I) doubly encapsulated 2 : 2 dimeric host-guest complexes (2a, 2b, 3 and 4). Two receptor units encapsulate a carbonate ion, via hydroxide induced aerial CO fixation (complex 5), and a sulphate anion (complex 6), respectively, in the presence of excess tetrabutylammonium hydroxide and bisulphate salt. H NMR titration and 2D NOESY experiments corroborate the solution-state binding and encapsulation of hydrated/non-hydrated halides and oxyanions via N-HA hydrogen bonding.