最新刊期
卷 ， 期 10 ， 2017
- 摘要：This article highlights some recent progresses in side-on liquid crystalline elastomer (LCE) researches, including their preparation, functions and possible applications. LCEs are networks formed by lightly crosslinked liquid crystalline polymers, which show both liquid crystalline order of the mesogens and elasticity of the polymeric networks. Owing to their interesting properties, LCEs are highly competitive candidates as stimuli-responsive materials in sensors, actuators, microfluidics and biomimicking devices and other areas. Developing new microstructures and realizing better stimuli-responsive functions have drawn a wide range of attention in recent years. Side-on LCE is an important category of LCEs, in which mesogenic units are waist-connected to the backbone of a polymer, and the mesogens tend to form nematic phase within the polymer network. Fabrication of LCE microstructures is a newly developing area with great growth potential. Taking use of elastomer (PDMS) molds, soft-lithographic methods have been used to fabricate LCE microstructures, which include micropillars and microwires. Soft-lithography has proved to be a feasible way to prepare LCE microstructures as shown by previous studies. LCE capillary fabricated by homemade tubular liquid crystal cell has been developed and employed to mimic the peristaltic crawling locomotion of earthworms. Upon the motion of heat source outside along the capillary axis, a crawling speed of 0.31 mm s-1 is achieved. The kinematics of the biomimetic locomotion has been studied and rationalized with a five-stage model. This crawling locomotion of the LCE capillary can be potentially applied in biomimetic miniature robots and so on. Gold nanorods (AuNRs), which are different from commonly used azobenzene photochromic moieties and carbon nanotubes, have been incorporated into LCE networks to achieve light responsiveness. AuNRs possess advantages in durabiltiy and photothermal conversion efficiency compared with the others. By incorporating AuNRs in side-on LCEs, light-responsive LCE/AuNRs composites have been developed by taking use of the photothermal effect of AuNRs. With inclusion of less than 1 wt% of AuNRs, a fast (within 3 s) light actuation has been achieved in LCE/AuNR composite actuators upon laser irradiation. By employing LCE gel, the phase transition temperature of LC network is reduced and the light-responsive function at room temperature has been achieved by AuNRs. In this article, some challenges to develop novel microstructures and realize more efficient stimuli-responses by using side-on LCEs are also discussed from perspectives of the authors.关键词：Liquid crystalline elastomers;Side-on;Microstructures;Light responsive
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发布时间：2021-01-26 - 摘要：Holographic polymer dispersed liquid crystals (HPDLCs) are one type of polymer composites in the form of periodically distributed polymer-rich phase and LCs-rich phase with ordered structure. HPDLCs are typically formed via photopolymerization induced phase separation of monomer/LCs mixtures. Despite of the extensive research on HPDLCs since 1993, it remains challenging to tune and quantitatively describe the photopolymerization kinetics, gelation behaviour, and degree of phase separation, for the aim of achieving HPDLCs with predesigned regular structure and desired electro-optical performance. This review summarizes the influence of the photoinitiating system, monomer structure, and doping of inorganic nanomaterials on the structure and performance of HPDLCs. The deployment of photoinitibitor, which held competitive and synergetic photoinitiation and photoinhibition functions, was found to be able not only to trigger the photopolymerization upon laser light exposure, but also to decrease the photopolymerization rate, to delay the gelation, thus helping the formation of HPDLCs with a high diffraction efficiency of 90%. The first photoinitibitor was composed of 3, 3'-carbonylbis(7-diethylaminocoumarin) (KCD) and a co-initiatorN-phenylglycine (NPG). The photoinitiation and photoinhibition functions were also noted later in a normally used photoinitiating system composed of rose bengal (RB) and N-phenylglycine (NPG). Hyperbranched monomer was disclosed to be able to decrease the mixture viscosity and the reaction rate, and also to delay the gelation. Consequently, HPDLCs with a diffraction efficiency of 94% and one-dimensional photonic structure were afforded on the basis of the employment of hyperbranched monomer because of the enhanced phase separation. Acrylamide monomer was found to optimize the phase separated structure, offering HPDLCs with a high diffraction efficiency of up to 98%. The doping of mercaptoethanol functionalized nano-ZnS was found to decrease dramatically the driving voltage while maintaining regular structure and high diffraction efficiency of HPDLCs. These ZnS nanoparticles were expected to be localized in the polymer rich-region to increase the conductivity of the region. The numerical relationship between the degree of phase separation of HPDLCs and gelation time of monomer/LCs mixtures is also highlighted. We believe that there remain opportunities to increase simultaneously the diffraction efficiency while decreasing the driving voltage of HPDLCs. Colored 3D holographic image storage and other practical applications of HPDLCs should be further advanced.关键词：Polymer dispersed liquid crystals;Holography;Photopolymerization;Phase separation;Image storage
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发布时间：2021-01-26 - 摘要：Discotic side-chain liquid crystalline polymers (SCLCPs) are expected to develop into a new generation of flexible organic polymer as advanced optoelectronic functional materials, by combining the order and optoelectronic properties of discotic liquid crystals and the flexibility and excellent film-forming advantages of polymers. This article introduces the research progress of discotic SCLCPs. Based mainly on the research progress of our group, we focus on summarizing and commenting the controlled preparation of triphenylene (TP) based discotic SCLCPs through controlled/living radical polymerization, as well as expoundingmolecular weight (MW) effect and spacer length influence of discotic SCLCPs.We have successfully realized the controllable preparation of well-defined TP polyacrylate discotic SCLCPs via reversible addition-fragmentation chain-transfer (RAFT) polymerization for the first time. Then, discrete columnar stack (DCS) based intracolumnar stacking mode has been proposed accounting for the remarkable MW effect at degree of polymerization (DP)around 20. Particularly, positive coupling effect (PCE) is disclosed for discotic SCLCPs, that is, the strong coupling effect of the shorter spacers is more favorable for the formation of ordered columnar mesophases, in striking contrast with the renowned classical longer flexible spacer decoupling principle derived from calamitic SCLCPs, complementing the missing theoretical short board. The polyacrylate SCLCPs with butoxy TP side-groups have been designed and synthesized based on these principles, showing a very high charge carrier mobility of one to two orders of magnitude higher than those reported as measured by the time-of-flight (TOF) technique. Our preliminary macromolecular engineering practices are further extended into the field of inducing assembly to form homochiral helical superstructures of electron donor-acceptor polymer complexes by doping with chiral guest acceptors, as well as controlled preparation and properties studies of cyclic polymers and block copolymers. The controllable preparation of discotic SCLCPs and the elucidation of some fundamental issues, such as MW effect and the spacer length influence, will provide guidance for the rational design and controlled synthesis of such kind of important organic polymer semiconducting materials, and lay a foundation for boosting their optoelectronic device applications.关键词：Discotic side-chain liquid crystalline polymer;Molecular weight effect;Positive coupling effect;Controlled synthesis;High charge carrier mobility
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发布时间：2021-01-26
Feature Articles
- 摘要：The concept of mesogen-jacketed liquid crystalline polymers (MJLCPs) was proposed by Prof. Qifeng Zhou in the late 1980s, as the third approach for the design of liquid crystalline polymers (LCPs). MJLCPs are side-chain polymers with some physical properties similar to those of main-chain LCPs. They are rigid or semi-rigid polymers with controllable shapes (rods or sheets) and sizes. MJLCPs can be prepared by controlled polymerizations such as different living free radical polymerizations and ring-opening metathesis polymerization, and thus their chain lengths can be easily adjusted. The diameter of a rod-like MJLCP or the width of a sheet-like MJLCP can be tuned by changing the size of the side chain. MJLCPs can self-organize into supramolecular columnar liquid crystalline (LC) phases for rod-like MJLCPs or smectic LC phases for sheet-like MJLCPs. They can be used as the rigid backbone to construct homopolymers with hierarchically self-assembled structures, such as main-chain/side-chain combined LCPs. In addition, the rod-like MJLCP with tunable length and diameter provides an excellent building block in forming novel LC block copolymers that can self-assemble into hierarchical nanostructures. MJLCPs can also be used as side chains in polymer brushes and other polymers with special architectures. Furthermore, various functional materials have been also developed based on MJLCPs, including homopolymers, block copolymers, and polymer brushes. The development in MJLCPs largely benefits from the advancement of macromolecular self-assembly. Various designable, predictable, and controllable self-assembly strategies have elevated the level of research on MJLCPs, which also broadens the content of polymer chemistry and polymer physics. The results show that the "jacketing" effect of side chains plays an important role in regulating the ordered structures of MJLCPs. In this review, we mainly discuss the recent development in the design, synthesis, control of liquid crystalline phases, self-assembly of block copolymers, and properties and application of the MJLCP-based functional materials in China. Finally, challenges in the field of MJLCPs are summarized, and prospects for further development are presented.关键词：Mesogen-jacketed liquid crystalline polymer (MJLCP);Supramolecular liquid crystalline phase;Self-assembly;Soft matter
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发布时间：2021-01-26
Reviews
- 摘要：In order to understand in depth the chirality transfer during the radical polymerization of vinylbiphenyl monomers, the homopolymerizations of chiral monomer, (+)-2-[(S)-sec-butyloxycarbonyl]-5-(4'-hexyloxyphenyl)styrene, and achiral monomer, 2-(n-butyloxycarbonyl)-5-(4'-hexyloxyphenyl)styrene, as well as their copolymerization were carried out. The effects of the polymerization temperature and solvent on the chiroptical properties of chiral homopolymers, the chiral monomer content on the chiroptical properties of copolymers, and the supramolecular chirality of polymerization media on the chiroptical properties of the homopolymers derived from achiral monomer were systematically investigated. All the resultant homopolymers and copolymers containing chiral units took helical conformations with an excess of screw sense and showed much more intensive optical activities than the monomer. It was found that decreasing polymerization temperature and using liquid crystalline reaction media favored obtaining polymers with large optical rotations. The effect of using ordered reaction media on the optical activity of polymer was larger than that of lowering reaction temperature. This was probably due to the increased stereoregularity of polymer main chain yielded in liquid crystalline phase, which diminished the number of helical reversal. The incorporation of chiral monomer could induce an excess of helix sense of copolymer main chain. Contrary to "sergeants-and-soldiers" effect, where a tiny amount of chiral monomer can endow the copolymer with the optical activity equal to that of the homopolymer consisting of chiral monomer, the optical rotations of copolymers scaled up linearly with the chiral component. It was considered that the length of helical block between two helical reversals was too short for the copolymer units to effectively cooperate and amplify the chirality of stereocenters in the pendant groups. The polymer obtained from the polymerization of achiral monomer in cholesteric phase showed no discernible optical rotation. These results suggested that the vinylbiphenyl polymers studied in this work possessed dynamic helical conformations and their optical rotations were mainly relied on the stereoregularity of polymer main chain and the chiral atoms of the pedant groups.关键词：Vinylbiphenyl monomer;Helix-sense-selective polymerization;5CB;Cholesteric liquid crystal;Chirality
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发布时间：2021-01-26 - 摘要：We synthesized a series of ILCPs contained imidazolium based on “Jacketing” effect via radical polymerization, poly(2,5-bis{[6-(4-butoxy-4′-imidazolium phenyl) k-alkyl] oxy carbonyl} styrene bis (fluoroborate) salts) (denoted as Pk-6-BF4, k represents the number of carbon in the alkyl tails, k = 4, 8, 12, 16). Especially, we mainly focused on their phase behaviors and the supra-molecular structures. Firstly, thermogravimetric analysis (TGA) showed that the decomposition temperature of ILCPs exceeded 320 ºC, revealing the excellent thermal stability of the samples. Differential scanning calorimetry (DSC) results showed that the samples with relatively short alkyl tail (Pk-6-BF4, k = 4, 8) had only glass transition temperature (Tg), while the samples with relatively long alkyl tail (Pk-6-BF4, k = 12, 16) also exhibited a melting peak, indicating that increasing the tail length resulted in the crystallization of the alkyl. Polarized light microscopy (PLM) results showed that the liquid crystalline (LC) texture always existed prior to the decomposition, indicating that this kind of ILCPs showed a broad LC temperature. One-(1D) and two-dimensional (2D) wide-angle X-ray diffraction (WAXD) results indicated that Pk-6-BF4 (k = 4, 8, 12, 16) formed SmA phase, wherein the side-chain mesogens were perpendicular to the main-chain. Combining the experimental data and the calculated result, we could conclude that the side-chain molecular packing adopted an interpenetrating mode. Furthermore, reconstructed relative electron density map by fast Fourier transform algorithm (FFT) was used to confirm the above results. The FFT result revealed that the increase of alkyl tail length would increase not only thed-spacing of the layer but also affect the interaction between the ions and the side chains, resulting in different molecular packing within SmA phase. It is evident that molecular packing of the ordered structure of ILCPs can be changed by tuning the length of the alkyl tail, which is beneficial to pave a way for the applications of ILCPs.关键词：Ionic liquid crystal polymers (ILCPs);"Jacketing" effect;Imidazolium;Phase behavior;Phase structure
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发布时间：2021-01-26 - 摘要：The self-assembled structure, from hydrogen-bonded copolymers containing poly(4-vinylpyridine) (P4VP), linear surfactant pentadecylphenol (PDP) and dendritic molecules, 1-[4'-(3",4",5"-tridecyloxy benzoyloxy)phenyleneoxycarbonyl]-3-[(4"-hydroxyphenyl)oxycarbonyl]benzene (12CBP), was investigated. The ternary complex system is named as P4VP(12CBP)x(PDP)y (x + y = 1)) which was prepared via solution blending method. It has been reported that P4VP(12CBP)x possess hexagonal columnar structure at x ≥ 0.3 and P4VP(PDP)x possess lamellar structure. Despite the different shapes and self-assembled properties from 12CBP and PDP, FTIR, DSC, POM and SAXS studies revealed that the ternary supramolecular copolymer system forms a homogeneous phase, instead of phase separation. At x ≥ 0.5, P4VP(12CBP)x(PDP)y possesses a homogeneous hexagonal columnar phase. Each column is constructed with P4VP as polymer backbone tethered with mixed side chains. The lattice parameter is smaller than that of the corresponding P4VP(12CBP)x+y and decreases gradually with decreasing x. In this case, the P4VP polymer chains are surrounded by 12CBP and PDP molecules which would induce “defects” from shape difference of the molecules. While the results show that such kind of “defects” didn’t prevent the columnar phase formation. The formation of each column with randomly distributed 12CBP and PDP would increase the system entropy. Meanwhile, smaller PDP provides more free volume, especially in alkoxy segment, and further increases the conformational entropy of the side chains. At x < 0.5, P4VP(12CBP) x(PDP)y is amorphous with layer like fluctuation, instead of columnar phase. In this case, the relative grafting density of the linear side chains is larger than that of dendritic side chains, which could not stabilize the columnar phase formation. Meanwhile the existence of small amount of 12CBP tends to interrupt the lamellar mesophase formation. AFM topographies of P4VP(12CBP)x(PDP)y thin films also support the formation of homogeneous phase. The typical fingerprint patterns from hexagonal columnar phase are gradually interrupted with decreasing x. At x < 0.5, only irregular morphology could be detected. So the surface patterns of such kind of supramolecular copolymer thin films could be easily controlled by varying x and y.关键词：Supramolecular copolymer;Hydrogen bond;Side-chain liquid crystalline polymer;Hexagonal columnar phase
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发布时间：2021-01-26 - 摘要：We report a novel near-infrared-responsive photothermal conversion reagent/liquid crystal elastomer composite material. Nowadays, most of the near-infrared absorbing inorganic metal nanoparticles can poison platinum and other precious metal catalysts, due to the chemical properties of these metal nanoparticles or their stabilizers (such as long chain thiols, quaternary ammonium salts,etc.), which cause the failure to prepare inorganic metal nanoparticle/liquid crystal elastomer composites through classical Finkelmann two-step hydrosilylation reaction. In order to solve this problem, we apply a fast two-step thiol-ene photoaddition technique, by embedding near-infrared-responsive copper sulfide nanoparticles into liquid crystal elastomer matrix, and a composite film, based on copper sulfide nanoparticle/liquid crystal elastomer with near-infrared-responsiveness, is successfully fabricated for the first time. Water-soluble CuS nanoparticles are first synthesized, and oil-soluble CuS nanoparticles are prepared by exchanging the sodium citrate stabilizer with poly(3-mercaptopropyl methylsiloxanes) (PMMS). The latter is mixed with PMMS, mesogenic monomers, crosslinkers and photoinitiators. The mixture is cast into a polytetrafluoroethylene mould and UV-illuminated at room temperature for 3 min to provide a pre-crosslinked liquid crystal elastomer composite film, which is further hung up and uniaxially stretched. The suspended pre-crosslinked liquid crystal elastomer film is UV-irradiated again at room temperature for another 15 min. to accomplish the second thiol-ene photo-crosslinking to obtain the composite film consisting of monodomain copper sulfide nanoparticle/liquid crystal elastomer. This composite material is thoroughly investigated using ultra-violet spectroscopy, transmission electron microscopy, polarized optical microscope, differential scanning calorimetry, and one-dimensional X-ray scattering. The experimental results demonstrate that this composite has a room-temperature nematic liquid crystal phase with a high-quality monodomain alignment. Most importantly, this composite film can perform a fast and reversible two-dimensional shrinking motion under irradiation of near infrared light with a wavelength of 980 nm .关键词：Photothermal conversion;Liquid crystal elastomer;Copper sulfide nanoparticles;Near infrared light;Thiol-ene click chemistry
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发布时间：2021-01-26 - 摘要：A series of monomers 4'-alkoxy-4-biphenol methacrylates MbiCm, with different alkoxy tail lengths (m = 1, 2, 4, 6, 8, 10, 12, 14, 16, 18), and their corresponding polymers PMbiCm were synthesized via free radical solution polymerization. The phase transition temperature and thermal stability of the polymers were studied by DSC and TG. Experimental results revealed that all the polymers were liquid crystal and exhibited high clear points. The clear point of the polymers was first decreased and then increased with increasing the alkoxy chain length. All the polymers showed excellent thermal stability, and their decomposition temperatures were all above 310 ºC. The novel P6biCm/paraffin composite, form-stable phase change materials (FSPCM), was prepared by introducing PMbiCm into paraffin. The minimum gelation concentration (MGC) and gel-to-sol transition temperature (TGS) were tested by tube-testing method. It was found that the gelation stability of PMbiCm was closely linked with alkoxy chain length. PMbiCm (m = 1, 2, 4, 6) were insoluble in paraffin at high temperature, and not able to form gel in paraffin. PMbiCm (m = 8, 10) were partly paraffin-soluble, while PMbiCm (m = 12, 14, 16, 18) formed stable gel in paraffin. The MGC and TGS decreased with the increase of the alkoxy tail length owing to enhanced interaction between the polymer and paraffin. The thermal properties and rheological properties were studied. The results showed that the PMbiCm/paraffin were of high phase transition enthalpy, excellent thermal stability and high gel strength. The structure and morphology of the FSPCMs were also investigated by FTIR, POM and SEM. The results revealed that paraffin was restricted because the gelators PMbiCm could self-assemble into three-dimensional netted structures, leading to the formation of shape-stable PCMs without leakage even above their melting point of the phase change materials.关键词：Side-chain liquid crystal polymer;Form-stable phase change materials;Self-assembly;Energy storage
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发布时间：2021-01-26 - 摘要：POSS core organic-inorganic hybrid dendrimer (POSS-G1-BOC) was successfully designed, synthesized and introduced into LC (liquid crystal) guest molecules (5CB) to prepare supermolecular LC physical gels with strong mechanical strength and new-style stimuli-responsive properties. The highly thermo-stable LC gel could withstand temperature as high as 117 °C with the addition of gelators as low as 0.3%. And it had excellent mechanical properties that could maintain its own independent shape within 17% strain even influenced by an external small force. The recover-ability of the LC gel also showed excellent mechanical properties. The microstructure of the system had obvious spiral status and was quite different from previous loofah-like gel networks. LC guest molecules were more likely to influence the self-assembling process of gelators and they were different from the remarkable effect of common solvents. The appearance of spiral fibers in the system without any chiral molecules might indicate the change of self-assembly mechanism in essential. Based on these systematical studies of the LC gel, including its response characteristics, assembly mechanisms and mechanical properties, it was found that the LC gel had many outstanding properties towards light, electric current, magnetic field and heat etc. which could be widely used in the field of display materials, overcoming the natural “flowing and orderly” properties of liquid crystal molecules. As an example of the application of LC gels, sandwiched LC light scattering display device was prepared based on transparent flexible and stretchable conductive films (PU/AgNWs) . The device could realize the high-constrast display effect driven at a low voltage (10 V, DC) and it could be used under the condition of being bent to the curvature as high as 0.14 cm−1. Meanwhile, it could still keep its electrically controlled response characteristics as being stretched to 120% of its original length. It might be used in the field of wearable devices, smart responsive materials in the future.关键词：Liquid crystal (LC) gel;POSS;Dendrimer;Stretchable;Photoelectric response;Display
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发布时间：2021-01-26 - 摘要：Liquid crystalline elastomers (LCEs) can show reversible shape change when the materials go through isotropic-liquid crystal phase transition (Ti). To get such actuation, LCEs have to be aligned into monodomain samples, in which the mesogens are orientated more or less in a uniform direction. Normally, LCEs are covalently cross-linked, which makes the alignment very difficult. We have previously shown that this problem can be solved by designing LCEs with exchangeable links. The material for demonstration was synthesized by reacting an epoxy-terminated biphenyl mesogen with sebacic acid in the presence of triazobicyclodecene catalyst for transesterification. The resultant material is in fact a liquid crystalline vitrimer. When the material is stretched above the topology freezing transition temperature (Tv), the accelerated transesterification reaction allows topology adjustment. The alignment can be fixed by cooling afterwards. However, as the Ti is very close to Tv in this sample, it is easy for the alignment to disappear when the temperature increases to above Ti to trigger the actuation. This not only limits the operating temperature range, but also destroys the alignment after multiple heating-cooling cycles. Consequently, it is desirable to increase the distance between Ti and Tv by reducing Ti. To this end, a second epoxy-terminated cyanostilbene mesogen (EP11) was added into the main chain of the liquid crystalline vitrimer. The result shows that the copolymerization of the two types of mesogens can effectively decreases Ti without affecting the Tv too much. It broadens the range between Ti and Tv. The more EP11, the lower Ti. When the content of EP11 is 20 mol%, Ti is 82 ºC, which is 31 ºC lower than the previous liquid crystalline vitrimer. The copolymer can also be used to make into monodomain LCE by stretching at high temperature. The resultant monodomain LCE has a similar reversible elongation-contraction actuation ratio as the previous liquid crystalline vitrimer. More importantly, the large distance between Ti and Tv makes it possible to trigger the actuation by heating it to a temperature of 15 ºC above Ti without destroying the alignment. Little fatigue has been identified after repeating the reversible elongation-contraction actuation for 120 times.关键词：Liquid crystal elastomer;Vitrimer;Liquid crystal-isotropic phase transition temperature (Ti);Reversible actuation
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发布时间：2021-01-26 - 摘要：We have studied the microphase phase separation behavior of a series of rod-coil diblock copolymers withpoly(2,5-bis[4-methoxyphenyl]oxycarbonyl)styrene) (PMPCS) as the rod and poly(ε-caprolactone) (PCL) as the coil. PMPCS is a typical mesogen-jacketed liquid crystalline polymer, of which the hexatic columnar nematic (ΦHN) phase can develop from the amorphous state upon heating irreversibly once the chain conformation becomes extended. It is found that the PCL-b-PMPCS samples with amorphous PMPCS behave similar to the coil-coil diblock copolymer, with the microphase separated morphology mainly determined by the volume fraction of PMPCS (fPMPCS). At the temperature above the glass transition temperature of PMPCS (~116 ℃), the transition from amorphous phase to ΦHN phase of PMPCS blocks occurs. This induces the “order-order” and/or “disorder-order” transition of the phase morphology, resulting in the lamellar morphology existing in a wide range of fPMPCS from 40% to 80%. In this case, PCL-b-PMPCS presents the typical feature of rod-coil diblock copolymer. Using one-dimensional correlation function to analyze the small-angle X-ray scattering data measured at 200 ℃, we obtained the thicknesse of PMPCS and PCL domain (LPMPCS and LPCL) in the lamellar structures. A linear relationship is identified, LPMPCS = 0.2NPMPCS(nm), with NPMPCS as the degree of polymerization of PMPCS block. As the chain axis of PMPCS block is parallel to the normal of the lamellae, we conclude that the diblocks form a “single-layer smectic A” lamellar phase, and more importantly,LPMPCS is the extended chain length of PMPCS block, which can be well controlled by polymerization. For PCL block, a scaling of LPCL~NPCL0.85 (NPCL is the degree of polymerization of PCL block) is observed, indicating that the molten PCL block is highly stretched. We further estimated the interfacial area per rod-like PMPCS (S/X) in the lamellar phase, which is always smaller than the cross section area of PMPCS rod in the ΦHN phase. Combining with the liquid crystallinity of samples measured by wide-angle X-ray diffraction, we consider that the variation of S/X reflects that, near the PMPCS/PCL interface, the PMPCS segments are not packed in ΦHN phase. This is mainly due to the strong segregation between the molten PCL and the liquid crystalline PMPCS which can cause the PMPCS blocks to be further stretched. For a fixed NPCL, the smaller S/X is, the larger LPCL is. However, a linear relationship of LPCL(S/X) = 0.21NPCL (nm3) can be realized, wherein the value of slope is the volume of PCL repeating unit.关键词：Mesogen-jacketed liquid crystalline polymer;Rod-coil diblock copolymer;Microphase separated lamellar phase;Molecular weight dependence
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发布时间：2021-01-26
Research Article
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