01375nas a2200277 4500008004100000022001400041245012700055210006900182260007700251300001400328490000700342520039900349653001800748653002000766653001500786653001800801653001600819100002100835700001200856700001800868700001600886700001800902700002500920700002100945856013100966 2013 eng d a0947-653900aHydrophobic and hydrophilic balance and its effect on mesophase behaviour in hydroxyalkyl ethers of methyl glucopyranoside0 aHydrophobic and hydrophilic balance and its effect on mesophase  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a5041-50490 v193 a

Four series of monosubstituted methyl -D-glucopyranoside hydroxyalkyl ethers were prepared and their thermotropic and lyotropic self-organising properties were investigated in terms of the hydrophobichydrophilic balance with respect to their molecular structures. The results obtained lead us to a new understanding of the forces that drive the formation of condensed soft-matter phases.

10acarbohydrates10aliquid crystals10amesophases10aSelf-assembly10asoft matter1 aSingh, Madan, K.1 aXu, Rui1 aMoebs, Sylvie1 aKumar, Anil1 aQueneau, Yves1 aCowling, Stephen, J.1 aGoodby, John, W. uhttp://library.ncl.res.in/content/hydrophobic-and-hydrophilic-balance-and-its-effect-mesophase-behaviour-hydroxyalkyl-ethers-002257nas a2200253 4500008004100000022001400041245012900055210006900184260000800253300001200261490000600273520138200279653001401661653003801675653002001713653002201733653001501755100001801770700002001788700002101808700002201829700002301851856012901874 2020 eng d a2367-093200aConjunctive photoluminescence enhancement through plasmonic and photonic band-gap pathways in a chiral self-assembled system0 aConjunctive photoluminescence enhancement through plasmonic and  cAUG a582-5910 v43 a

We describe two parallel pathways for enhancing the intrinsic photoluminescence of an organic emitter dispersed in a liquid crystal (LC) medium. The pathways have independent origins: (i) Metal enhanced fluorescence (MEF) incorporating gold nanoparticles having an organic shell of pro-mesogenic cholesterol esters; and (ii) Matching the photonic band gap (PBG) due to the helical structure in a self-assembled chiral system with the excitation wavelength. This unprecedented combination of both pathways achieves a level of photoluminescence exceeding the sum of the contribution from the individual methods. This conjunctive protocol results in an overall enhancement by a factor of 37 between the emitter dispersed in a non-chiral LC and that appealing to both MEF and PBG pathways. Circular polarized luminescence measurements also show that this protocol helps in effective discrimination of chiral light achieving a large dissymmetry factor whose magnitude (+0.33) is comparable to the highest recorded to date. Electric field switching between two states is also shown to result in appreciable fluorescence modulation. Being generic in nature the protocol employed can be adapted to a variety of situations with the large magnitude as well the modulation level suitable for applications such as biosensors, various analyte detection, and other photonic devices.

10achirality10acircularly polarized luminescence10aliquid crystals10aphotonic band-gap10aplasmonics1 aBaral, Marlin1 aPrasad, Krishna1 aBhat, Sachin, A.1 aNayak, Rashmi, A.1 aYelamaggad, C., V. uhttp://library.ncl.res.in/content/conjunctive-photoluminescence-enhancement-through-plasmonic-and-photonic-band-gap-pathways02812nas a2200241 4500008004100000022001400041245016300055210006900218260000900287300000800296490000700304520194400311653001602255653002202271653001102293653002002304653002502324100003002349700002102379700002402400700002302424856012302447 2020 eng d a0250-470700aWide thermal range, exclusive occurrence of technically significant chiral nematic phase: synthesis and mesomorphism of cholesterol-based non-symmetric dimers0 aWide thermal range exclusive occurrence of technically significa cAUG  a1880 v433 a

Fifteen new non-symmetric chiral dimers belonging to three different series have been synthesized and evaluated for their mesomorphic properties. They are formed by interlinking cholesterol with salicylaldimine (SAN) cores (with reverse imine groups) via an omega-oxyalkanoyloxy spacer. Within a series, the length of the terminaln-alkoxy tails has been varied for a fixed even-parity spacer. Three even-parity spacers such as 4-oxybutanoyloxy, 6-oxyhexanoyloxy and 8-oxyoctanoyloxy have been used to join two cores, whereas the terminal tails such asn-butyloxy,n-hexyloxy,n-octyloxy,n-decyloxy andn-dodecyloxy chains have been attached to the SAN core. Microscopic and calorimetric experimental results show that all the dimers behave identically exhibiting the chiral nematic (N*) phase solely, which was authenticated by powder X-ray diffraction studies carried out on some selected samples. In the vast majority of the cases, this phase is thermodynamically stable, and while cooling, it exists over a wide thermal range covering room temperature (RT) due to supercooling. This finding is notable given the fact that the N* phase possesses technologically significant optical properties. At RT, the N* phase displayed one of the iridescent colours characteristically caused by interference and diffraction of the reflected and scattered light. A comparative study reveals that the lengths of both the terminal chain and central spacer influence the clearing temperature of the dimers, and also the temperature range of the N* phase. The selective reflection measurements revealed that the pitch of the N* phase is either temperature sensitive or temperature insensitive. Temperature-dependent circular dichroism (CD) spectra were recorded for the planar texture of the N* phase formed by a dimer, as a representative case. The presence of an intense negative CD band suggests the left-handed screw sense of the N* phase helix.

10aCD activity10acholesteric phase10adimers10aliquid crystals10aselective reflection1 aNayak, Rashmi, Ashwathama1 aBhat, Sachin, A.1 aRao, D., S. Shankar1 aYelamaggad, V., C. uhttp://library.ncl.res.in/content/wide-thermal-range-exclusive-occurrence-technically-significant-chiral-nematic-phase02254nas a2200277 4500008004100000022001400041245011700055210006900172260000900241300001100250490000800261520133500269653001201604653002701616653002901643653002001672653002301692100001701715700002201732700001801754700002001772700001901792700001901811700002101830856012501851 2022 eng d a0167-732200aElliptically birefringent chemically tuned liquid crystalline nanocellulose composites for photonic applications0 aElliptically birefringent chemically tuned liquid crystalline na cNOV  a1203260 v3663 a

Cellulose nanocrystals (CNCs) based photonic materials are one of the promising materials in the recent trends. The liquid crystalline behavior of the CNCs can be tailored to different advanced applications. The proposed research investigates the potential of CNCs as an optically active material. CNCs were tuned to hydroxypropyl nano cellulose (HPNC) with the degree of substitution 1.39. The prepared liquid crystalline HPNC were dispersed in various concentrations of monomethyl ether of polyethylene glycol to get waterborne materials with specific optical anisotropy. The extraction, modification, and morphology of the CNCs were investigated using NMR (Nuclear Magnetic Resonance), TEM (Transmission Electron Microscopy), XRD (X-ray Powder Diffraction), and FESEM (Field Emission Scanning Electron Microscopy) analysis. The prepared HPNC was analyzed using a hot stage POM (Polarized Optical Microscope) for optical anisotropy. The thermal stability of prepared CNCs and HPNC was also investigated. Upon optimization using rheology and POM, it was found that at the ratio of 1:1, HPNC (5 wt%) and mPEG (40 wt%) had the most distinct optical properties. The potential of the prepared materials can be further explored in sensing, smart coating, and security materials. (C) 2022 Elsevier B.V. All rights reserved.

10abagasse10aCellulose nanocrystals10aElliptical birefringence10aliquid crystals10aoptical anisotropy1 aSingh, Shiva1 aBhardwaj, Shakshi1 aVerma, Chhavi1 aChhajed, Monika1 aBalayan, Kajal1 aGhosh, Kaushik1 aMaji, Pradip, K. uhttp://library.ncl.res.in/content/elliptically-birefringent-chemically-tuned-liquid-crystalline-nanocellulose-composites02465nas a2200253 4500008004100000245018700041210006900228260000900297300001600306490000600322520149000328653001901818653002301837653002001860653002301880653001901903100001901922700002101941700003801962700003102000700003002031700003102061856011902092 2025 eng d00aVastly increased mesophase range due to superstructure formation from in situ prepared gold nanoparticles with liquid crystalline ligands: toward enhanced optoelectronic applications0 aVastly increased mesophase range due to superstructure formation cMAY  a10340-103500 v83 a

Gold nanoparticle (Au NP)-liquid crystal (LC) composites have gained considerable interest in developing cutting-edge electro-optical materials. This study introduces an innovative synthetic approach that significantly augments the capabilities of Au NP-LC composites by utilizing an amine-functionalized LC as both a reducing and capping agent in the refined Brust-Schiffrin method. In its standard form, this method yields Au NP-LC composites with appealing features like improved clearing temperature. However, the optical characteristics do not display any additional features and resemble simple LC-ligand functionalized Au NP, attributed here to the surplus LC employed to obtain the dual capabilities of reduction and capping. Thus, it was gratifying to observe a dramatic enhancement in mesophase stability with the removal of just a few percentages of excess LC, which is attributed to a remarkable and unprecedented one-dimensional superstructure formation. Furthermore, the removal of surplus LC caused the composite to exhibit Fano-like resonance in the UV-vis spectrum, a noteworthy optical feature likely resulting from dynamic plasmonic interactions, including plasmon-polariton interactions and lattice plasmon modes. Thus, the simple yet robust protocol employed yields Au NP-LC composites with an ultrawide thermal range of the mesophase that paves the way for realizing next-generation electro-optic materials featuring enhanced performance and response.

10aFano-resonance10agold nanoparticles10aliquid crystals10ananosoftcomposites10asuperstructure1 aDuggal, Muskan1 aKhatavi, Santosh1 aYelamaggad, Channabasaveshwar, V.1 aRao, Doddamane, Sreenivasa1 aPrasad, Subbarao, Krishna1 aPrasad, Bhagavatula, L. V. uhttp://library.ncl.res.in/content/vastly-increased-mesophase-range-due-superstructure-formation-situ-prepared-gold