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Tyrosyl-DNA phosphodiesterase 2 (TDP2) is a recently discovered DNA repair enzyme that can repair topoisomerase 2-mediated DNA damage, resulting in cancer cell resistance. In this study, two compounds, robustadial A and B, were isolated from a fraction of the ethyl acetate extract of Eucalyptus globulus Labill. fruits based on TDP2 inhibition screening. The biological experiments indicated that robustadial A and B have TDP2 inhibitory activity with EC50 values of 17 and 42 μM, respectively, but no tyrosyl-DNA phosphodiesterase 1 inhibition at 100 μM. Robustadial A showed significant synergistic effects with the anticancer drug etoposide in four human cancer cell lines, non-small cell lung cancer cell line (A549), prostate cancer cell line (DU145), breast cancer cell line (MCF-7), colorectal adenocarcinoma cell line (HCT-116), and chicken lymphoma cell line (DT40), and chicken lymphoma cell line complementation with human TDP2 (DT40 hTDP2) with combination index values ranging from 0.21 to 0.74. This work will facilitate future efforts for the development of robustadial A-based TDP2 selective inhibitors.

Cholesteric liquid crystals with selective reflection have important applications in the field of light control and optical thin films. In this study, a series of side-chain cholesteric liquid-crys...

In this study, a series of cholesteric liquid crystal elastomers (ZSD series) was synthesised by hydrosilylation reaction among monomer ML1 containing cholesteryl group, monomer ML2 as the crosslin...

In this study, we synthesised two series of cholesteric liquid crystal polymers CPQ and CPZ series. First, we prepared four different monomers ML1 containing a cholesteryl group, ML2 containing a c...

We synthesized two series of cholesteric liquid-crystal elastomers by hydrosilylation among monomers MA containing a cholesteryl group, MB (MC) containing a phenolic hydroxyl group and MD a...

In this study, we designed, synthesised and characterised two series of cholesteric liquid crystal polymers, QP series and ZP series. With polymethylhydrosiloxane as the main chain, QP series were ...

A series of hexamethylenetetramine-based ionic liquid crystals (ILCs) containing cholesterol derivatives and different anions including Br−1, BF4−1, PF6−1, H2PO4−, CF3COO−, TsO−, and CSA-SO3- were synthesized, and the characterization, possible applications and self-assembly behavior were discussed. The ILCs were synthesized from bromine-containing precursor liquid crystal, which was made of cholesterol and 4-bromobutyryl chloride. The ILCs showed smectic A (SmA) mesophase. For these hexamethylenetetramine-containing ILCs, Tg, Ti and liquid-crystalline temperature range reduced slightly in sequence of Br−1, BF4−1, PF6−1, H2PO4−, CF3COO−, TsO−, and CSA-SO3- anions. But the d-spacing of the lamellar structure in SmA phase increased in this sequence of these anions. Because of microphase separation and ionic electrostatic attraction, the SmA layers and self-assembly were formed in these ILCs. The ionic conductivities of the ILCs significantly increased in SmA phase due to unique facilitated ion transport pathways of lamellar ionic channels.

Eleven new acylphloroglucinols, including six new formylated phloroglucinol-monoterpene meroterpenoids, eucalyprobusals A–F (1–6), one monomeric acylphloroglucinol, eucalyprobusone B (7), and four dimeric acylphloroglucinols, eucalyprobusones C–F (8–11) were purified from the fruits of Eucalyptus robusta. The establishment of the structures of 1–11 was achieved by a combination of NMR and HRESIMS data analyses, electron circular dichroism (ECD), and single-crystal X-ray diffraction. Compounds 6, 8, and an inseparable mixture of 10 and 11 were found to be potent AChE inhibitors with IC50 values of 3.22 ± 0.36, 3.82 ± 0.22, and 2.55 ± 0.28 μΜ, respectively. Possible interaction sites of 6, 8, 10, and 11 with AChE were investigated by means of molecular docking studies, and the results revealed that AChE residues Asn87, Ser125, Thr83, Tyr133, Tyr124, Tyr337, and Tyr341 played crucial roles in the observed activity of the aforementioned compounds.

A series of quaternary phosphonium salts based on ionic liquid-crystalline polymers which were synthesised by triphenylphosphine and brominated polysiloxanes containing cholesteryl mesogens. The chemical structures, liquid crystalline properties and antimicrobial performance of [ChP]Brs were investigated by a series of test methods. [ChP]Brs showed smectic A mesophase with a wide temperature range of liquid crystalline phase in the heating and cooling cycles. The glass transition temperature and clearing point temperature decreased with the increase of triphenylphosphine content. While the increase of phosphorus content lead to the increase of antibacterial properties of polymers. The liquid crystal polymer provides full spatial support for complete contact between phosphorus ions and bacteria, So that the quaternary phosphonium salt can be fully sterilised.

Self-assembly of both ionic aggregates and mesogens in one polymer system represents the capability integrating intermolecular interactions and functions of materials. A series of ionic liquid-crystalline network polymers (ILCNs) containing cholesterol derivatives, siloxane backbone and ionic pyridinium sulfonic groups are synthesized, and the characterization, self-assembly behavior, and possible applications are discussed. The ILCNs are made from sulfonic acid-containing precursor polymers synthesized by use of cholest-5-en-3-ol-(3β)-4-(allyloxy)benzoate, 4-(allyloxy)benzenesulfonic acid and poly(methylhydro)siloxane. The ILCNs show a cubic mesophase and a smectic A (SmA) mesophase. The SmA layers develop saddle splay curvature and adopt the shape of infinite minimal surfaces, therefore self-assembly of bicontinuous cubic phases takes place due to ionic electrostatic attraction and asymmetry derived from the chiral cholesterol elements. Large ionic conductivity and remarkable thermal stability of the ILCNs provide promising opportunities for ion transport devices because they provides facilitated ion-transport pathways including smectic ordering and three-dimensional interconnected ionic channels.

Four multi-arm liquid crystals (LCs) based on chenodeoxycholic acid, termed as 2G-PD, 2G-IB, 2G-BD and 5G-GC, respectively, have been synthesised by convergent method, which nematic LC, 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoic acid, was used as side arm, and chenodeoxycholic acid (CDCA) was used as the first core, 1,2-propanediol (PD), isosorbide (IB), 4,4′-biphenyldiol (BD) and glucose (GC) were used as the second core, respectively. The first generation product, CDCA2EA, displayed cholesteric phase. The second generation products 2G-BD and 5G-GC displayed cholesteric phase, while 2G-PD and 2G-IB exhibited nematic phase. The multi-arm LC, 2G-IB, did not display cholesteric phase although the two cores were all chiral ones. The result indicated that chirality of the second core sometimes made the multi-arm LCs display nematic phase when cholesteric CDCA-derivative were introduced into the second core. Some attention should be paid on molecular conformation besides the introduction of chiral cores for multi-chiral-core LCs to obtain cholesteric phase.

The cholesteric polysiloxanes (PLQ series) were obtained by reacting cholesteric monomer and phenolic hydroxyl monomer in different ratios with polysiloxanes. The chiral azo-containing polysiloxanes liquid-crystalline elastomers (LCEs) were synthesised by esterifying PLQ series with acyl acid of azo diacid catalysed by 4-dimethylaminopyridine (DMAP). The chemical structures and mesomorphic properties of monomers and polymers were confirmed by conventional spectroscopic methods. The elastomers displayed elastic properties, reversible phase transition and high thermal stability. The Tg values changed irregularly and Ti values decreased at the beginning and then increased afterwards. The chiral azo-LCEs showed colourful textures and a Grandjean texture could be observed, which exhibited a red shift with increasing content of azo moiety. PLQ2–PLQ6 exhibited selective reflection in the visible light region, but PLZ1–PLZ4 can only observe selective reflection when appropriate mechanical pressure was imp...

A series of side-chain cholesteric polysiloxanes (PQ) were synthesised with poly(methyl--hydrogeno)siloxane, cholesterol (4-allyoxybenzoate) (M1), and 4-hydroxyphenyl-4(allyloxy) phenylpropanoate (M2), 4-allyloxy-4 ‘-cyanobiphenyl (M3). Then azo-containing chiral liquid crystalline polymer (PZ) were synthesised with PQ and 4-(4-hexyloxyphenylazo) benzoic acid (M4) by esterifying catalysed by 4-dimethylaminopyridine which is a new synthetic way. The chemical structures of monomers and polymers were confirmed by conventional spectroscopic methods and test methods for liquid crystal properties. The photo-induced isomerisation of the polymer is investigated by UV–vis spectroscopy. Weight lost temperatures (5%) for all polymers were greater than 298°C. The results showed that the introducing of azo moieties makes the polymer more stable on thermo dynamics. The transition temperatures of the polymers PQ and PZ exhibited some regularity as the change of ingredients of polymers. PQ series showed Grandjean...

Novel kinds of polymerised ionic liquid crystals (PILCs) bearing imidazolium and bipyridinium groups were synthesised and characterised in this work. Some bromo-polyesters were synthesised in an esterification chain reaction using 2,3-dibromosuccinyl dichloride, isophthaloyl chloride and 4,4′-biphenol. The polyester imidazolium bromides (PIBs) and polyester dipyridinium bromides (PDBs) were obtained by a quaternisation reaction between the bromo-polyesters, N-methylimidazole and 4-4′-bipyridine, respectively. The polyester imidazolium tetrafluoroborates (PITs) and polyester dipyridinium tetrafluoroborates (PDTs) were synthesised using the corresponding PIBs and PDBs in an anion-exchange reaction. The chemical structures, liquid crystalline properties and molecular weights of these polymers were characterised by multiple experimental techniques. All the PILCs including PIBs, PDBs, PITs and PDTs display smectic A phase on heating and cooling cycles. The liquid-crystalline properties of bromo-polyest...

The cholesteric polysiloxanes (P series) were obtained by reacting cholesteric monomer and phenolic hydroxyl monomer in different ratios with polysiloxanes. And then the chiral azo-containing polysiloxanes (AP series) were synthesized by esterifying P series members with the acryl acid of azo acid catalyzed by DMAP. The chemical structures and liquid crystal (LC) properties of the monomers and polymers were characterized by use of various experimental techniques such as FTIR, 1H-NMR, POM, DSC, TGA, XRD and ultraviolet-visible. Experimental results proved that obtained polymers were in accordance with the molecular design. The transition temperatures of the polymers exhibited a decreasing trend as the content of the cholesteric units increased and became higher by introducing the azo mesogenic core. The temperatures at which 5 % weight loss occurred are higher than 280 °C. P2–P6 showed blue Grandjean textures and exhibited selective reflection in the visible light region. AP series also possessed Grandjean textures, and the colors exhibited red shift with increasing content of azo moiety. On the heating cycles, when appropriate mechanical pressure was imposed on the polymers, AP2–AP6 selectively reflect visible light; however, there are no reflection peaks in the UV-Vis spectrum without the stimulation of mechanical pressure. All polymers exhibit left-handed optical activity due to having the same cholesteric group. The optical rotation direction of AP changes from left to right when increasing the UV irradiation time, and the photoresponsive behaviors of AP series are also investigated.

With polymethylhydrogensiloxane (PMHS) as the main chain, two series side-chain cholesteric liquid crystal polymers (ChLCPs) with different liquid crystal side chain lengths were prepared by hydrosilylation reaction. Then two series of cholesteric fluorescent liquid crystal polymers (FL-ChLCPs) were obtained by etherification reaction. The obtained FL-ChLCPs have both excellent mesomorphic behavior, and great photoluminescent property. We confirmed their chemical structures by FT-IR, and 1H NMR spectroscopy, and found them with excellent thermal stability by TGA. We characterized their mesomorphic behavior and thermal performance by POM, DSC and XRD, and confirmed all the polymers belonged to cholesteric phase. FL-ChLCPs emitted different-intensity fluorescence under UV light, and we found some regularity by PL spectrum.

Novel chiral liquid-crystalline (LC) bromo-polysiloxanes (IP, IIP and IIIP) were graft copolymerized in a one-step hydrosilylation reaction by use of polymethylhydrogenosiloxane, cholest-5-en-3-ol(3β)-10-undecenoate and 4-bromobut-1-ene. A pyridyl-containing LC monomer cholesteryl isonicotinate (CIN) was synthesized and characterized. Some LC ionomers [IP–IIIP-Py][X] (X = Br) were synthesized by use of CIN and the bromo-polysiloxanes. Other LC ionomers [IP–IIIP-Py][X] (X = BF4, PF6, Tf2N) were prepared by metathesis of the pyridinium bromides. The chemical structure and liquid-crystalline properties were investigated by various experimental techniques. All the bromo-polysiloxanes display a smectic A (SA) mesophase when they are heated and cooled, while all these LC ionomers show a chiral smectic C (S*C) phase on heating, and exhibit SA and S*C phases on cooling. The LC ionomers show a narrower range of LC temperature than the corresponding bromo-polysiloxanes. For the LC ionomers bearing homologous pyridinium cations and different anions, the glass transition temperature, mesophase–isotropic phase transition temperature and LC temperature range tend to reduce, and the spontaneous polarization value increases slightly in the sequence of Br−, BF4−, PF6−, and Tf2N−. Rearrangement of smectic layers due to electrostatic attraction and ion aggregation of cholesteryl pyridinium salt mesogens lead to the formation of the S*C phase for these LC ionomers.

A new series of cholesteric fluorated branched-arm liquid crystals (CHFBALCs) compound (MFA1–MFA4), with isosorbide as chiral core, was synthesized. Four precursors of branched-arm FA1–FA4 were obtained firstly and then were esterized separately with isosorbide to get four chiral branched-arm liquid crystalline (MFA1–MFA4). The structures and properties were characterized by conventional spectrum methods, thermal analysis and texture analysis. The results showed that FA1–FA4 all were nematic phase with schlieren, threaded-like or droplet texture. When the isosorbide was successfully inducted, the phase of FA1–FA4 turned into cholesteric phase with oily streak texture, finger print texture or cholesteric droplets. The values of melting point and clearing point for FA1–FA4 and MFA1–MFA4 all changed irregularly, which may be due to the effect of different branched arm, warping of chiral agent and fluorine atom. MFA1–MFA4 had the same handedness as isosorbide core and did not show selective reflection. MFA3 and MFA4 were hopeful to realize the combination of the processability of polymers and the mobility of small molecules.

Cholesteryl-containing ionic liquid crystals (ILCs) 1-cholesteryloxycarbonylmethyl(propyl)-3-methyl(butyl)imidazolium chlorides ([Ca-Me-Im]Cl, [Ca-Bu-Im]Cl, [Cb-Me-Im]Cl and [Cb-Bu-Im]Cl) and corresponding imidazolium tetrachloroaluminates ([Ca-Me-Im]AlCl4, [Ca-Bu-Im]AlCl4, [Cb-Me-Im]AlCl4 and [Cb-Bu-Im]AlCl4) were synthesized in this work, and the chemical structure, LC behavior and ionic conductivity of all these ILCs were characterized by several technical methods. The imidazolium-based salts with Cl− ions showed chiral smectic A (SA*) phase on both heating and cooling cycles, while the tetrachloroaluminates exhibited chiral nematic (N*) phase. The mesophase was confirmed by characteristic LC textures observed by polarizing optical microscopy and typical diffractogram obtained by X-ray diffraction measurements. The samples with similar cholesteryl-linkage component showed similar phase transition temperature and entropy, indicating the cholesteryl component influence predominately on the phase transition rather than alkyl substituents on the imidazole ring. The imidazolium tetrachloroaluminates display relatively low phase transition temperature compared with the precursor chlorides. The functional difference in LC behavior and ionic conductivity were discussed by investigated the structural difference between the Cl−-containing and AlCl4—containing materials. The imidazolium chlorides exhibited layer structure both in crystal and mesophase states, and should be organized with a ‘head-to-tail’ organization to form interdigitated monolayer structures due to the tight ion pairs. But the imidazolium tetrachloroaluminates displayed layer structure only in crystal phase, and should be organized in ‘head-to-head’ arrangements form bilayer structures due to loose combination of ion pairs despite of hydrogen-bond and electrostatic attraction interaction.

Precursor polymer MP series were synthesized by 4-allyloxybenzoic acid cholesteryl ester (M) and 4- hydroxyphenyl 4- (propionyloxy) benzoate (P). We obtained novel themotropic side-chain liquid crystal polymer MPZ series by esterification between MP series and 4-((4-ethoxyphenyl) diazenyl) benzoic acid (Z). Differential scanning calorimetry (DSC) was used to measure the thermal properties of those polymers, and the mesogenic properties were characterized by polarized optical micrograph (POM), DSC and X-Ray. MP series exhibited yellow, green, blue and purple Grandjean textures. MPZ series also showed colorful Grandjean textures. They exhibited thermotropic liquid crystal properties in a broad mesogenic region.

A new series of side-chain chiral liquid crystalline elastomers derived from M1 (cholest-5-3-ol(3β)-4-(2-propen-yloxy)]benzoate) and MC(2,5-[3,5-bis(4-(3-(4-(allyloxy)phenyl)propanoyloxy)benzoyloxy)benzoic acid]isosorbide diester). The structures of monomers and elastomers measured by using Proton Nuclear Magnetic Resonance Spectra (1H-NMR) and Fourier transform infrared spectroscopy (FTIR) separately are consistent with our design. IIP~VIP all appeared blue Grandjean (GJ) texture on the heating cycle or cooling cycle. The glass sheets of IIP~VIP were made under 150°C and measured its ultraviolet–visible spectrophotometry by PerkinElmer Lambda 950 instrument (Shelton, CT, USA). IIP~VIP all have absorptions at about 481~483 and 561~562 nm. The optical activities were measured at different temperatures on heating and cooling cycles. And the blue selective reflection of IIP~VIP on the round glass sheet can be seen. The elastomers containing less than 6 mol% of the crosslinking units displayed elasticity, rev...

Fluorinated chiral liquid-crystalline elastomers (LCEs) were graft copolymerized by a one-step hydrosilylation reaction with polymethylhydrogenosiloxane, a fluorinated LC monomer 4-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctanoyloxy)phenyl 4-(undec-10-enoyloxy)benzoate ( PPUB ) and a chiral crosslinking LC monomer (3 R ,3a R ,6 S ,6a R )-6-(undec-10-enoyloxy)hexahydrofuro[3,2- b ]furan-3-yl 4′-(4-(allyloxy)benzoyloxy)biphenyl-4-carboxylate ( UHAB ). The chemical structure, liquid-crystalline behavior and polarization property were characterized by use of various experimental techniques. The effective crosslink density of the LCEs was characterized by swelling experiments. The thermal analysis results showed that the temperatures at which 5% weight loss occurred were greater than 250 °C for all the LCEs, and the residue weight nearby 600 °C increase with increasing chiral crosslinking components in the polymer systems. All the samples showed chiral smectic C mesophase when they were heated. The glass transition temperature and mesophase-isotropic phase transition temperature of fluorinated elastomers increased slightly with increase of chiral crosslinking mesogens in the polymer systems, but the enthalpy changes of mesophase-isotropic phase transition decreased slightly. In XRD curves, all the samples exhibited strong sharp reflections at small angles suggesting smectic layered packing arrangement. These fluorinated chiral LCEs showed 0.1–0.2 μC/cm 2 of spontaneous polarization with increasing chiral crosslinking component.

A series of new azobenzene side chain liquid crystalline polymers were synthesized by two different azo mesogen monomers, 4-((4-(ethoxycarbonyl) phenyl) diazenyl) phenyl 4-(allyloxy) benzoate (M1) and (4-((4-(ethoxycarbonyl) phenyl) diazenyl) phenoxy) methyl acetyl 4-(allyloxy) benzoate (M2). All polymers (P1~P8) were synthesized by graft polymerization using polymethyl hydrosiloxane as backbone. Their chemical structures were confirmed by FTIR and 1HNMR spectra. The mesomorphic properties and phase behavior were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and thermogravimetric analyzer (TG) measurements. The results showed that P1~P8 exhibited thermotropic liquid crystalline properties and revealed nematic thread texture with wide mesophase temperature ranges. The temperatures when 5% weight loss occurred were higher than 305°C, which declared that the synthesized azobenzene liquid crystalline polymers had a high thermal stability.

A series of new main-chain liquid-crystal polymers (LCPs) were prepared from sebacoyl chloride (SD) and various amount of 4, 4-Dihydroxy-2, 2-dimethyl Benzalazine (DDBA) and isosorbide (ISO). The liquid crystal (LC) properties were investigated by polarized optical microscope (POM), differential scanning calorimetry (DSC) and X-ray diffraction measurements. P1 exhibited a typical nematic thread texture, which contains no ISO. P2-P7 are Sc* and N LCPs, which exhibited broken fan-shaped texture and droplet texture. The introduction of chiral units into the polymers led to a change of mesomorphase, as compared with P1.

In order to explore the effect of ionic groups on the properties of the liquid-crystalline polymers, a series of new main-chain liquid-crystal ionomers (LCIs) were prepared from sebacoyl chloride (SD), brilliant yellow (BY) and various amount of 4, 4-Dihydroxy-2, 2-dimethyl Benzalazine (DDBA) and isosorbide (ISO). The structures of the polymers were characterized by FT-IR and UV spectroscopies. Differential scanning calorimetry (DSC) was used to measure the thermal properties of the polymers. The mesogenic properties were investigated by polarized optical microscope (POM), differential scanning calorimetry and X-ray diffraction measurements. The results show that the LCIs are chiral smectic C (SC*) and nematic (N) LCIs exhibiting broken focal-conic texture and schlieren texture. The introduction of ionic units in the LCIs led to the clearing point and mesogenic temperature range increasing and the glass-temperature decreasing, but did not affect the mesogenic type and texture, as compared with the corresponding polymer P0.

A new series of two-arm (MB1, MB2), four-arm (MB3), six-arm (MB4) chiral liquid crystalline compound containing isosorbide as chiral core were first synthesized. Four precursors of branched-arm B1~B4 were obtained at first and then were esterized separately with isosorbide and got four chiral branched-arm liquid crystals (MB1~MB4). The chemical structures and LC properties of the liquid crystalline molecule were measured by spectrum and thermal analysis techniques. XRD curves of MB1~MB4 samples only showed broad peaks at wide-angle, but no sharp peak was seen for all the samples. The results showed that MB1~MB4 appeared cholesteric phase with oily streak texture or lined texture and finger print texture. Isosorbide successfully induced cholesteric phase. The values of melting point and clearing point for MB1~MB4 decreased. The quantity of branched-arm and chiral core had effects on their liquid crystalline properties.

The synthesis of new chiral monomer 4-((4-(allyloxy) benzoyl) oxy) phenyl (S)-4-(2-methylbutoxy) benzoate (Mch), crosslinking agent hexane-1,6-diyl diacrylate (CA), and liquid crystal polymer elastomers (E1-E7) containing (S)-(-)-2-Methyl-1-butyl group is presented. The phase behavior and mesomorphism of the polymers were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and x-ray diffraction. The effect of the content of crosslinking units on the phase behavior and mesomorphism of elastomers was discussed. The chiral LCEs (E1-E7) exhibited elasticity, reversible phase transitions, and cholesteric Grandjean texture. The experimental results demonstrated that the glass transition temperature and isotropic temperature of Chiral LCEs decreased with increasing the content of crosslinking agent, but the cholesteric phase was not disturbed.

A series of main-chain liquid-crystalline polymers (LCPs) with pendant sulfonic acid groups have been synthesized by use of biphenyl-4,4′-diol, 6,7-dihydroxynaphthalene-2-sulfonic acid, and bis(4-(chlorocarbonyl)phenyl) decanedioate in a one-step esterification reaction. Emeraldine base form of polyaniline (PAN) is doped by the synthesized sulfonic acid-containing LCPs to obtain PAN–LCP ionomers. A series of electrorheological (ER) fluids are prepared using the synthesized PAN–LCP ionomers and silicone oil. The chemical structure, liquid-crystalline behavior, dielectric property of LCPs, and PAN–LCP ionomers, and ER effect of the ER fluids are characterized by use of various experimental techniques. The synthesized sulfonic acid-containing LCPs and PAN–LCP ionomers display nematic mesophase. The PAN–LCP ionomers show a slight elevation of glass transition temperatures and decrease of enthalpy changes of nematic–isotropic phase transition compared with corresponding sulfonic acid-containing LCPs. The relative permittivity of the PAN–LCP ionomers is much higher than that of the corresponding sulfonic acid-containing LCPs. The ER effect of the PAN–LCP ionomer dispersions is better than PAN dispersions, suggesting a synergistic reaction should be occurred among liquid crystalline component, and PAN part under electric fields. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3395–3403, 2013

A series of new chiral side-chain liquid crystalline polysiloxanes(P0-P7) bearing cyano groups were synthesized with a cholesteric LC monomer and a nematic monomer with cyano units(electron withdrawing). The chemical structures and LC properties of the polymers were measured by spectrum and thermal analysis techniques. The obtained polymers were soluble in many solvents and the specific rotations showed negative values and increased with the increasing content of chiral reagent. P1 showed grained texture of smectic A, P2~P7 showed lined texture of chiral smectic C(SC*). XRD curves of P1~P7 samples showed sharp and strong peaks at low angle, but no sharp peak was seen for P0 sample. The temperatures at which 5% weight loss occurred(Td) were greater than 300oC for all the polymers, which reveals all the polymers were stable. And the Tg values of polymers were all low. The Tg and Ti values are all increased with the increasing chiral contents. All the polymers displayed wide range of liquid crystal phase on heating and cooling cycle.

A series of main-chain liquid-crystalline polymers containing maltose were synthesized by interfacial condensation reactions of sebacyl chloride, 4,4’-Dihydroxy-2,2’-dimethyl Benzalazine(DDBA), and 1-O-[4´-O-(α-D-glucopyranosyl)-ß-D-glucopyranosyl]-methanol(MM). The effects of MM on characteristics of liquid-crystalline properties were studied. P1- P3 exhibited nematic mesophase on heating and cooling cycle, while P4- P7 exhibited both chiral smectic A and nematic mesophases on heating cycle and nematic mesophase on cooling cycle. P8 did not exhibit any mesophase on heating and cooling cycle. The glass-transition temperature decreased with increasing concentration of MM.

A new series of two-arm ( MA1 , MA2 ), four-arm ( MA3 ) and six-arm ( MA4 ) chiral liquid crystalline compounds containing isosorbide as the chiral core were synthesised. Four precursors of branched-arm A1–A4 were first obtained, and then were esterised separately with isosorbide to obtain four chiral branched-arm liquid crystals ( MA1–MA4 ). The structure and properties have been characterised. The results show that MA1 was smectic–cholesteric phase with a fan-like and oily streak texture; MA2–MA4 showed a cholesteric phase with oily streak texture, or lined texture and finger print texture. Isosorbide successfully induced a cholesteric phase. The melting point and clearing point values for MA1–MA4 first increased and then decreased. The branched-arm and chiral core quantity affected the liquid crystalline properties. At the same time, the difference in side-arms resulted in different directions of rotation. MA1–MA2 showed right-handed rotation and had selective reflection; MA3–MA4 demonstrated left-hand...

Several novel chiral side-chain liquid crystalline (LC) polysiloxane resins containing epoxy groups and mesogenic components have been graft copolymerized by a one-step hydrosilylation reaction with poly(methylhydrogeno)siloxane, an epoxy monomer 2-(allyloxymethyl)oxirane, and chiral fluorinated liquid-crystalline monomers 4′-(4-(allyloxy)benzoyloxy)biphenyl-4-yl 6-(perfluorooctanoyloxy)hexahydrofuro[3,2-b]furan-3-yl adipate and 4′-(4-(undec-10-enoyloxy)benzoyloxy)biphenyl-4-yl 6-(perfluorooctanoyloxy)hexahydrofuro[3,2-b]furan-3-yl adipate. The synthesized epoxy resins are cured using 4,4′-diaminodiphenyl-methane in mesophase state under a magnetic field to obtain crosslinked oriented elastomers. The chemical structures, LC properties and surface morphology of the monomers, the resins and the liquid crystalline elastomers (LCEs) are characterized by use of various experimental techniques such as FTIR, 1H NMR, EA, TGA, DSC, POM, and X-ray measurements. The mesomorphic properties of the synthesized resins and corresponding oriented elastomers are influenced by the terminal perfluorocarbon chains components effectively. The resins show chiral nematic and chiral smectic C phases ( S c * ), and S c * are frozen in their corresponding oriented elastomers. The LC phases are verified by X-ray measurements, and the orientational order parameters of the oriented LCEs are calculated as well.

In the present work, a ester of glucose (a) with 4-(4-(ethoxybenzoyloxy) phenoxy) -6-oxohexanoic acid side–arms has been synthesized. Compared withbandc, reported previously,ahad the same side-arms but different chiral core. The phase behaviors of three star-shaped liquid crystals (a, b, c) have been compared and studied, and the effect of the different structure of chiral core on the phase behaviors of the star-shaped liquid crystals has been discussed. a, b andcdisplayed cholesteric phase, unlike the nematic side arm.a, b andcwere all laevo-rotationary, unlike their parent cores. The melting temperature of a, b andcdecreased with the increase of the sugar ring of the chiral core. The mesomorphic region ofaon cooling cycle was wider than that on heating cycle. Forbandc, the case was similar.

A series of new chiral side-chain liquid crystalline polymers with electron donor-acceptor action were prepared containing chiral monomer with donor group and nematic LC monomer with acceptor group. All polymers were synthesized by graft polymerization using polymethylhydro- siloxane as backbone. The mesomorphic properties were investigated by differential scanning calorimetry(DSC), polarizing optical microscopy(POM)，thermogravimetric analyses（TGA） and X-ray diffraction measurements(XRD). The chemical structures of monomers and polymers were confirmed by Fourier transform infrared (FTIR), proton nuclear magnetic resonance spectra(1H NMR and 13CNMR). M1 showed nematic phase and M2 turned out cholesteric phase on heating and cooling cycle. Polymers P3~P8 were cholesteric phase. Experimental results demonstrated that the glass transition temperatures and isotropization temperatures and the ranges of the mesophase temperature increased with increasing the content of chiral agent. All of the obtained polymers showed high thermal stability.

With the wide application of modern high technology in the field of physical education and training, to design a new system for the ensurance of the fairness of orienteering competitions, we developed the Fingerprint Electronic Timing System and Registering System and used them in orienteering competitions. The technical keys include the four points of fast extracting fingerprints, an invulnerable athlete registering system, large-capacity fingercards and a fast on-the-spot matching system. Thus a false-name entering during registrating process or in the course of the race can be avoided to ensure the fairness and authoritativeness of orienteering competitions.

With the rapid development of the internet towards broadbanding, fastspeeding and multimedia orienting, modern teaching methods or means based on network will be put into massive application. How to construct an overall systematic orienteering net courseware becomes the key to orienteering teaching. The network courseware differs from original multimedia teaching software in using environments, teaching functions and teaching effects. Therefore, from the characteristics of integrableware and its effect on orienteering teaching reform, this study proposes the integrating of orienteering teaching resource bank and multimedia making platform based on the integrableware idea, so as to achieve the aim of a new model and a new designing idea for orienteering courseware, i.e. to combine the basic teaching courseware, pictures and animation, microvideo units and document materials into an integrated organism to provide courseware for Orienteering teaching.

A novel perfluorinated liquid crystal 4′-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctanoyloxy)biphenyl-4-yl undec-10-enoate (PFOBU) was synthesized, which exhibited smectic C phase. Several liquid crystalline polymers (PI–PVI) were synthesized by use of poly(methylhydrogeno)siloxane, PFOBU, and cholesteryl 3-(4-allyloxy-phenyl)-acryloate. The chemical structures and liquid crystalline (LC) properties of the monomers and polymers, and some ferroelectric properties of the chiral smectic C (S C * ) phase were characterized by use of various experimental techniques. The effect of perfluorocarbon chains on phase behaviors of the fluorinated LC polysiloxanes was studied as well. PI and PII showed single chiral nematic (N*) mesophase when they were heated and cooled, but PIII, PIV, PV, and PVI containing more perfluorocarbon chain units exhibited S C * phase besides N* mesophase. Introduction of perfluorocarbon chain containing mesogens to the chiral cholesteryl-containing polymer systems resulted in a S C * mesophases, indicating that the fluorophobic effect could lead to microphase segregation and modifications of smectic mesophases from the chiral nematic phase.

Three esters of maltose (A1–A3) with 4–(4–(alkoxybenzoyloxy)phenoxy) –6–oxohexanoic acid (b1–b3) side-arms have been synthesised. All the maltose derivatives were laevo-rotationary, unlike their parent cores. The side arm b1 did not display liquid crystalline (LC) properties, and b2 and b3 displayed thermotropic nematic LC properties. The star-shaped compound (SSC) A1 with b1 side-arms did not display a mesomorphic phase. Unlike the nematic schlieren texture provided by side-arms b2 and b3, the star-shaped liquid crystals (SSLC) A2 and A3 displayed Grandjean and oily texture in the cholesteric phase. The results suggest that the LC properties of the side-arms have an important influence on the formation of LC properties in an SSC, and that the maltose core is important in determining the mesomorphic phase type. In other words, the SSC displayed LC properties only when the side-arms were also LC, and the maltose core induced a cholesteric phase in the SSLC with nematic side-arms. The mesomorphic regions fo...

Seven new cholesteric monomers (M-1−M-7) and the corresponding smectic comblike polymers containing cholesteryl groups (P-1−P-7) were synthesized. The chemical structures and purity were characterized by FT-IR, 1H NMR, and elemental analyses. The specific optical rotations were evaluated with a polarimeter. The mesomorphism was investigated by polarizing optical microscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction. The specific optical rotation values of these monomers and polymers with the same numbers of phenyl ring and terminal groups were nearly equal, however, they decreased with increasing the aryl numbers in the mesogenic core. M-1−M-7 showed oily streak texture and focal conic texture, or fingerprint texture, or spiral texture of cholesteric phase. P-1−P-7 showed the smectic A phase. The melting, clearing, and glass transition temperatures increased, and the mesophase temperature ranges widened with increasing the aryl number in the mesogenic core. Surprisingly, although the molecular structures of M-6 and M-7 were similar to those of M-4, namely the mesogenic cores contained three phenyl rings, their phase behavior had a considerable difference, and Tm and Ti of M-6 and M-7 were less than those of M-4. In addition, M-6 and M-7 also showed an obvious glass transition. TGA showed that all the polymers had good thermal stabilities.

Three star-shaped compounds (SSCs, c1 – c3 ), are synthesized by using melitose as the chiral core and monacid ( b1 , b2 and b3 ) as side arms, respectively. The side arms ( b1 , b2 and b3 ), in which terminal chains are different, are introduced into the hydroxyl groups of melitose by esterification, respectively. The chemical structures of c1 – c3 are confirmed by FT-IR and 1 H NMR. The roles played by the chiral core and the side arms in the mesomorphic properties of the SSCs are studied. b1 is not a liquid crystal (LC), while b2 and b3 are nematic LCs. c1 is not a LC, while c2 and c 3 are star-shaped LCs (SSLCs) and exhibit fingerprint texture of chiral nematic. c1 , c2 and c3 are all levo-SSCs, which are different from their parent cores. The absolute value of their specific rotation increases with the increase of the terminal chain length of the side arms. The melting temperature of SSCs decreases with the increase of the terminal chain length of the side arms. For c 2– c3 , their mesomorphic region increases with the increase of the terminal chain length of the side arms. The results suggest that the LC properties of the side arms play an important role in inducing LC properties of the SSCs and the chiral core induces the chiral nematic of SSLCs, which contain the nematic LCs as the side arms.

In this work the new-style nematic monomer M1 , chiral crosslinking reagent MC and a series of new side-chain cholesteric liquid crystalline elastomers derived from M1 and MC were prepared. The effect of the content of the chiral crosslinking unit on phase behaviour of the elastomers has been discussed. Polymer P1 showed nematic phase, P2 –P7 showed cholesteric phase, P3 formed Grandjean texture in the heating cycle and turned out a blue Grandjean texture in the cooling cycle, P2 –P3 with less than 6 mol% of chiral crosslinking agent gave rise to selective reflection. The elastomers containing less than 15 mol% of the crosslinking units displayed elasticity, reversible phase transition and high thermal stability. Experimental results demonstrated that the glass transition temperatures reduced first and then increased, and the isotropisation temperatures and the mesophase temperature ranges decreased with increasing content of crosslinking unit.

A series of new chiral side-chain liquid-crystalline polymers were prepared containing smectic-nematic monomer and nonmesogenic chiral monomer. All polymers were synthesized by graft polymerization using polymethylhydrosiloxane as backbone. The mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy, thermogravimetric analyses, and X-ray diffraction measurements. The chemical structures of the monomers and polymers obtained were confirmed by Fourier transform infrared, proton nuclear magnetic resonance spectra (1H NMR). M1 showed smectic (SB, SC) and nematic phase on the heating and the cooling cycle. Polymers P0–P2 were in chiral smectic A phase, while P3–P5 were in cholesteric phase, P6 has bad LC properties, and P7 has no LC properties. Experimental results demonstrated that nonmesogenic chiral moiety and LC mesogenic with long carbochain offered the possibility of application because of its lower glass transition temperature, and the glass transition temperatures and isotropization temperatures and the ranges of the mesophase temperature reduced with increasing the contents of chiral agent. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008