Crystalline Poly Research Articles

Transparent, thermoplastic, aliphatic polyesters through crystallization under molecular confinement

•We report segmented polyesters with nanoscale crystalline poly(L-lactic acid) domains •Polymers possess high modulus and elongation at break and can be melt processed •Solution processing yields transparent films that are degradable and cytocompatible •Films can be bonded by plasma activation and undergo infrared-activated shape change In semi-crystalline biodegradable polymers, uncontrolled evolution of crystallinity impacts processing and bulk properties, limiting their application. Through molecular confinement of low-molecular-weight poly(L-lactic acid) (PLLA) segments by polysiloxane blocks and processing at far-from-equilibrium conditions, PLLA crystallization into lamellae of a few nm in thickness with coherence lengths below 100 nm was achieved, thus giving access to films that are optically transparent for over 5 years, possess high Young’s modulus and elongation at break, undergo controlled degradation, and support functional endothelialization. The films possess a nanophase segregated bulk morphology with a hydrophobic siloxane-dominated surface that can be pressure bonded following cold oxygen plasma activation and low-temperature glassy PLLA domains interspersed by nanoscale crystalline physical crosslinks that enable glass transition temperature-triggered shape change. The segmented thermoplastic polyesters (STEPs) can additionally be processed using melt-extrusion printing into 3D objects, thus opening potential application opportunities in the fabrication of implantable/degradable electronics, smart textiles, and packaging. In semi-crystalline biodegradable polymers, uncontrolled evolution of crystallinity impacts processing and bulk properties, limiting their application. Through molecular confinement of low-molecular-weight poly(L-lactic acid) (PLLA) segments by polysiloxane blocks and processing at far-from-equilibrium conditions, PLLA crystallization into lamellae of a few nm in thickness with coherence lengths below 100 nm was achieved, thus giving access to films that are optically transparent for over 5 years, possess high Young’s modulus and elongation at break, undergo controlled degradation, and support functional endothelialization. The films possess a nanophase segregated bulk morphology with a hydrophobic siloxane-dominated surface that can be pressure bonded following cold oxygen plasma activation and low-temperature glassy PLLA domains interspersed by nanoscale crystalline physical crosslinks that enable glass transition temperature-triggered shape change. The segmented thermoplastic polyesters (STEPs) can additionally be processed using melt-extrusion printing into 3D objects, thus opening potential application opportunities in the fabrication of implantable/degradable electronics, smart textiles, and packaging.

Ion Conductivity of Liquid Crystalline Poly(substituted methylene)s Bearing Ionic Liquid Moieties at the Side Chain Ends

We have measured the ionic conductivity (σ) of liquid crystalline poly(substituted methylene)s (PMs) bearing ionic liquid (IL) moieties attached to the main chain via alkyl spacers. Four types of PMs investigated, differing in main-chain stereoregularity (atactic or syndiotactic) and the number of methylene units in the alkyl spacer (n = 6 or 12), have twice the σ of conventional polyacrylate ILs with similar glass transition temperatures. The highest σ of 5.9 × 10−5 S cm−1 is measured for the atactic PM with n = 12 at 30 °C. Poly(ionic liquid)s (PILs) based on lquid crystalline poly(substituted methylene)s (PMs) has twice high ionic conductivity (σ) than conventional PILs similar in the glass transition temperature. The highest σ value measured for these polymers with molecular weights more than 105 kDa is 5.9 × 10−5 S cm−1, greater than the maximum value of 3.0 × 10−5 S cm−1 expected for PILs.

Crystallization of Poly(ethylene oxide)-Based Triblock Copolymers in Films Swollen-Rich in Solvent Vapors

In this study, we employed a polymer processing method based on solvent vapor annealing in a confined environment to swell-rich thin films of polybutadiene-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) triblock copolymers and to promote their crystallization. As revealed by optical and atomic force microscopy, thin films of triblock copolymers containing a rather short crystalline poly(ethylene oxide) block that was massively obstructed by the other two blocks were unable to crystallize following the spin-casting process, and their further swelling in solvent vapors was necessary in order to produce polymeric crystals displaying a dendritic morphology. In comparison, thin films of triblock copolymers containing a much longer poly(ethylene oxide) block that was less obstructed by the other two blocks were shown to crystallize into dendritic structures right after the spin-casting procedure, as well as upon rich swelling in solvent vapors.

Booster Adhesion of Crystalline Poly(vinylidene fluoride) Binder by Heat Treatment for Ni‐rich Layered Oxide Cathode in Lithium‐ion Batteries

AbstractHigh energy density of lithium‐ion batteries is crucial for highly efficient battery systems. Ni‐rich layered oxide cathode materials with a high specific capacity have garnered considerable interest. Ni‐rich cathode materials exhibit rather large volume fluctuations during charging and discharging, unlike traditional cathode materials. This study investigated the electrochemical performance of a Ni‐rich cathode with a focus on controlling binder adhesion of poly(vinylidene fluoride) (PVDF), which is the most feasible cathode binder for battery manufacturing, to mitigate the failure mode of volume changes. A simple heat treatment of 200 °C over melting point is effective to enhance binding force by altering nanoscale alignment of PVDF. The study evaluates the electrochemical properties of the Ni‐rich cathode with different levels of binder adhesion to determine the optimal binder conditions for high performance.

Alkali-assisted deep-deamination to improve the crystallinity of poly(heptazine imide) for boosted photocatalytic H2 evolution

The poly(heptazine imide) (also known as heptazine-based crystalline carbon nitride, abbreviated as PHI) has drawn wide attention in solar energy conversion, which is profited from its improved photoinduced charge separation compared with melon-based carbon nitride. Nevertheless, the crystallinity of the samples synthesized by direct heat-treating precursors is low and further impede electron transport. This situation is especially prominent if precursors are used in large quantities and the reason is also unclear at present. Herein, this crucial issue was preliminarily revealed: the by-product HCl formed in the synthesis process has seriously restricted the deamination of PHI if it cannot be removed in time. Based on this, an original alkali-assisted method was proposed and demonstrated to realize deep-deamination for improving the crystallinity and extending π-conjugation of PHI. Benefit from this, alkali-assisted synthesized PHI illustrates significantly enhanced electron transport performance and further improved photocatalytic H2 evolution activity. The optimized PHI exhibits highly boosted photocatalytic H2 evolution activity of 2223 μmol h−1, which is 18 times that of original PHI synthesized without alkali-assistance. Additionally, the mechanism was further verified by density-functional theory (DFT) computations and the universality of alkali-assisted method was verified by using different kinds of alkali.

Experimental analysis on solar photovoltaic (SPV) panel for diverse slope angles at different wind speeds

The current work focuses on gaining the most competent panel for a solar powered setup located at Hyderabad latitude. One of the majority functional solar forms of energy is solar photovoltaic (SPV) system. The collectors used to pull out energy from the sun in the form of radiation. Electricity generation by means of SPV has grown to be a successful and efficient mode to exploit the sun’s energy (radiant energy) and loaded on the power grid. The main intention of this work is to investigatedivergent types of beneficially and readily available solar panels of mono crystalline and poly crystalline presented at Hyderabad latitude17.43oN, 78.43oE. Performances of each mono crystalline panel and poly crystalline panels having aperture area of 0.3072 m2 with concentration ratio 1, and slope angles (i.e. 14°, 16°, 18°) at diverse time interval from 10:00AM to 02:00PM from February to May 2018 are studied and the effect of wind speeds at 3 m/s, 4 m/s and 5 m/s over the output power generation from the panel are also determined.Same experiment is conducted on 1st April 2023 to study the performance of SPV panels. It was observed that 8% of energy increase by the SPV panels of both materials when these results are compared with old results experiment data which was conducted on 1st April 2018.

Integrating Fly Ash-Controlled Surface Morphology and Candle Grease Coating: Access to Highly Hydrophobic Poly (L-lactic Acid) Composite for Anti-Icing Application

New ways of recycling fly ash are of great significance for reducing the environmental pollution. In this work, biodegradable hydrophobic poly (L-lactic acid)/fly ash composites for anti-icing application were successfully fabricated via a facile solvent-volatilization-induced phase separation approach. A silane coupling agent of 3-(Trimethoxysilyl) propyl methacrylate was used to decorate a fly ash surface (FA@KH570) for strengthening the interface bonding between fly ash and poly (L-lactic acid). Moreover, FA@KH570 could obviously enhance the crystallinity of poly (L-lactic acid) (PLLA)/FA@KH570 composites, which accelerated the conversion from the liquid-liquid to the liquid-solid phase separation principle. Correspondingly, the controllable surface morphology from smooth to petal-like microspheres was attained simply by adjusting the FA@KH570 content. After coating nontoxic candle grease, the apparent contact angle of 5 wt% PLLA/FA@KH570 composite was significantly increased to an astonishing 151.2°, which endowed the composite with excellent anti-icing property. This strategy paves the way for recycling waste fly ash and manufacturing hydrophobic poly (L-lactic acid) composite for potential application as an anti-icing material for refrigerator interior walls.

Functionalization of various coffee husk biofibers on the rheological and thermomechanical properties of poly(butylene succinate)-urethane blended composites

Many studies have reported that surface-functionalized biofibers originating from plant waste can be used to improve the compatibility and processability of polymer blend systems. This study investigated the effects of size distribution and surface treatment of coffee husk (CH) biofibers on the rheological and thermomechanical properties of poly(butylene succinate)/thermoplastic polyurethane polymer blend composite. CH is a coffee waste with interlinked complex macromolecular structure of lignocellulose materials like cellulose, hemicellulose, and lignin. It was found that the handling and processability of the composites improved after the CH was surface-functionalized with diisocyanate/methacrylate prior to composite fabrication. Smaller-sized surface-treated CHs showed superior processability owing to the entanglement of fibers through the matrices associated with the improvement of interfacial adhesion. Therefore, the frequency-dependent rheological test revealed an increase in complex viscosity and storage modulus with the surface treatment and size reduction of CHs. Regardless of the size distribution, the degree of crystallinity of poly(butylene succinate) in the composites filled with surface-treated CHs reduced by about 20%. The composites with treated CHs also demonstrated superior thermal stability than their corresponding composites with raw CHs.

Poly(heptazine imide) ligand exchange enables remarkable low catalyst loadings in heterogeneous metallaphotocatalysis

The development of heterogeneous metallaphotocatalysis is of great interest for sustainable organic synthesis. The rational design and controllable preparation of well-defined (site-isolated) metal/photo bifunctional solid catalysts to meet such goal remains a critical challenge. Herein, we demonstrate the incorporation of privileged homogeneous bipyridyl-based Ni-catalysts into highly ordered and crystalline potassium poly(heptazine imide) (K-PHI). A variety of PHI-supported cationic bipyridyl-based Ni-catalysts (LnNi-PHI) have been prepared and fully characterized by various techniques including NMR, ICP-OES, XPS, HAADF-STEM and XAS. The LnNi-PHI catalysts exhibit exceptional chemical stability and recyclability in diverse C−P, C−S, C−O and C−N cross-coupling reactions. The proximity and cooperativity effects in LnNi-PHI significantly enhances the photo/Ni dual catalytic activity, thus resulting in low catalyst loadings and high turnover numbers.

Facile preparation of highly crystalline poly(L‐lactide) films with inversed wettability and their potential application in oil–water separation

AbstractHighly crystallized poly(L‐lactide) (PLLA) films with enhanced hydrophobicity are easily prepared by casting PLLA solution into a poor solvent like isopropyl alcohol (IPA). The crystallinity of the PLLA film can be controlled by PLLA's concentration, the kind of poor solvent, and the volume ratio of poor solvent dichloromethane (DCM). Results show the addition of poor solvents obviously accelerate the crystallization of PLLA film and enhance the crystallinity up to 48.7%. A lower volume ratio of IPA/DCM at higher PLLA concentration as well as a higher volume ratio of IPA/DCM at lower PLLA concentration is conducive to raising the crystallinity of the PLLA film. In the meanwhile, microscopy observation and wettability tests confirm the PLLA films present multidimensional microstructure including fibrils, lamellas, and flower‐like stacks or spherulite‐like superstructure, and display high porosity as well as enhanced hydrophobicity. Despite the volume ratio of IPA/DCM, the PLLA films prepared at lower concentrations display higher crystallinity, porosity as well as hydrophobicity than those prepared at higher concentrations. The highly crystalline PLLA films with enhanced porosity and hydrophobicity are supposed to be applied in oil–water separation, and so forth.

COMPARISON OF MECHANICAL PROPERTIES OF THE IMPLANT MATERIALS- TITANIUM, ZIRCONIUM AND PEEK USING THREE DIMENSIONAL FINITE ELEMENT ANALYSIS

Background And Objective:Dental implants have been universally accepted as the best option for prosthetic rehabilitation of missing teeth.A material of choice for manufacturing dental implants was for long time commercially pure titanium due to its excellent bio compatibility and mechanical properties. Zirconia seems to be a suitable alternative dental implant material because of its tooth like color and biocompatibility. The most promising novel alternative to titanium is polyetheretherketone (PEEK) which is a partially crystalline poly aromatic linear thermoplastic substance. The objective of this study is to study and compare the mechanical properties of titanium, zirconium and PEEK implant materials using three dimensional finite element analysis. Methodology: A randomly chosen computerized tomography was used to obtain the digital model in the initial phase of the work. Only the part portion corresponding to tooth number 35 will be extracted from this model. Screwed cylindrical implants of length 12 mm and diameter 4mm will be modeled and simulated to be placed in the section of the bone. The different models used were model A - Titanium, model B – Zirconium, and model C - PEEK implant models. All models were identical, except for the properties of the used materials and all were exported to the Ansys Workbench V10 finite elements simulation software. Vertical and oblique (45 degree) loads in relation to the long axis of the tooth with 100 N in magnitude were applied. Stress analysis performed by comparing the Von Mises stress components. Fatigue strength and mode of failure were also assessed for the three implant materials. Results: Maximum stress in the peri-implant bone when titanium implant was placed in 35 region was 281.40 Mpa under axial load of 100N. Maximum stress when zirconia implant was placed is 277.99 MPa and when peek implant was placed which amounts for 286.78Mpa. Titanium sustains more life cycle (832840.00) compared to Zirconium (743070.00) and PEEK has much less life cycle (302460.00). Factor of safety is rated on a scale of 0 -15 and results were Titanium (12.42) and Zirconium (11.16) had almost similar values. Peek (6.15) had low safety factor compared to Titanium and Zirconia. Conclusion:Titanium was superior to other two groups in all the properties considered. These results prove why Titanium is still considered to be the gold standard material of choice for dental implant fabrication.

Amide-Functionalized Polyolefins and Facile Post-Transformations

Direct copolymerization of olefins with polar monomers to produce functionalized polyolefins has attracted much attention; however, highly efficient incorporation of amide functions into polyolefins is a long-standing challenge because the amide function is pronounced to retard chain growth. In this contribution, Vince Lactam’s derivatives (VLH, VLMe, and VLBoc) that contain high ring strain and an amide moiety are utilized in ethylene copolymerization mediated by palladium catalysts. Amide-functionalized polyethylenes, poly(E-VLBoc)s, are accessible with key characteristics of high amide incorporations (up to 30.1 mol %), high copolymer molecular weights, and high catalytic activities. The incorporation of the amide comonomer converts crystalline poly(E-VLBoc)s (Tm = 115–125 °C) to noncrystalline and transparent poly(E-VLBoc)s (Tg = 98–196 °C, optical transmittance (T) = 87.6%–90.4%). Both characteristics of cyclic amide functions and high amide incorporations in poly(E-VLBoc) enable facile post-transformations under mild conditions to produce hydrogen bond-containing (-C(O)NH-) poly(E-VLH), difunctionalized (-COOH and -NHR) poly(E-VLNHBoc), and water-soluble ammonium-functionalized poly(E-VLNH3+). The ammonium functionality endows polyolefin with antibacterial properties.

Uniform Two-Dimensional Crystalline Platelets with Tailored Compositions for pH Stimulus-Responsive Drug Release.

Two-dimensional, size-tunable, water-dispersible particle micelles with spatially defined chemistries can be obtained by using "living" crystallization-driven self-assembly (CDSA) approach. Nevertheless, a major obstacle of crystalline particles in drug delivery application is the difficulty in accessing to cargo within crystalline cores. In the present work, we design four different types of biocompatible two-dimensional platelets with a crystalline poly(ε-caprolactone) (PCL) core, a hydrophobic poly(4-vinylprydine) (P4VP) segment, and a water dispersible poly(N,N-dimethyl acrylamide) (PDMA) block in ethanol by seeded growth method. Transferring those uniform platelets with tailored compositions to an aqueous solution in the presence of a hydrophobic drug leads to efficient encapsulation of the cargo in the P4VP segments via hydrophobic interactions. These drug-loaded platelets exhibit pH-responsive release behavior in aqueous media due to the protonated-deprotonated process of P4VP blocks in acidic and neutral solutions. This work provides initial insight into biocompatible PCL platelets with low dispersity and precise chemistry control in stimulus-responsive drug delivery fields.

Interface Manipulation of Composite Solid Polymer Electrolyte with Polydopamine to Construct Durable and Fast Li+ Conduction Pathways

Taking advantage of light weight, flexibility, and flame retardancy, solid polymer electrolytes (SPEs) provide a feasible solution to these safety concerns and to the enhancement of energy density for lithium-ion batteries (LIBs). However, the development of SPEs is still restricted by low ionic conductivity. Herein, we develop a type of SPE filler built by flower-like Co3O4 microspheres as a lithiophilic backbone and polydopamine (PDA) as a multifunctional coating for the engineering of the interphase properties of the polyether-based SPEs. The hierarchical structure of Co3O4 affords large interfacial contact area with SPEs and effectively suppresses the regular crystallinity of poly(ethylene oxide) (PEO) segments. Moreover, the PDA coating layers with diverse surface functionalities serve as a versatile mediator to finely tune ionic distribution and transport behavior via multiple Lewis acid–base interactions. We uncover the interphase characterizations and their synergistic effects to enhance Li+ conductivity and mechanical/electrochemical stability. This study provides intriguing alternatives for developing composite solid polymer electrolytes (CPEs), for which we further demonstrate the potential application of Co3O4@PDA-based CPEs in all-solid-state LIBs.

Crystallinity and temperature dependent mechanical properties of Poly(4-methyl-1-pentene)

Crystallinity and temperature dependent modulus in poly(4-methyl-1-pentene) were investigated over a wide temperature range covering glass transition of the amorphous phase. It turns out that the storage moduli of different samples decrease with the increase of crystallinity below Tg. The storage moduli of different samples are the same regardless of crystallinity at around 45 °C where the densities of crystalline and amorphous phases are identical. A model considering parallelly arranged crystalline skeleton and amorphous network allows a decomposition of the measured modulus into moduli of both phases. In addition to the fact that the modulus of amorphous phase in the glassy state is much larger than that of crystalline phase due to a higher density in amorphous phase than that of the crystals, a peculiar positive temperature dependent apparent crystalline phase modulus below Tg was observed. This seemingly anti-intuitive result can be understood by considering the strong constraint of the crystalline phase by the denser amorphous network at lower temperatures due to different thermal expansion coefficients of the two phases.

Improved piezoresistive sensing behavior of poly(vinylidene fluoride) / carbon black composites by blending with a second polymer

For the production of low-cost conductive polymer composites (CPCs), carbon black (CB) is a suitable conductive filler that provides higher piezoresistive sensitivity compared to highly anisotropic fillers such as carbon nanotubes. However, the use of CB containing CPCs as sensor materials is limited by high electrical percolation threshold (Φc) and poor signal linearity. In this work we demonstrate that the addition of either amorphous poly(methyl methacrylate) (PMMA, 20 wt%) or partially crystalline poly(butylene succinate) (PBS, 30 wt%) tunes the piezoresistive behavior of composites based on partially crystalline poly(vinylidene fluoride) (PVDF) and CB (3 and 4 wt%), due to a changed phase morphology and network arrangement. Significantly improved piezoresistive linearity compared to the corresponding composites with a pure PVDF matrix was achieved. Thereby, the sensitivity at small initial strains is not compromised. Furthermore, the addition of 30 wt% PBS reduced the electrical percolation threshold significantly, so that samples with the low amount of 1.5 wt% CB became available for piezoresistive testing. This blend composite shows a nearly linear piezoresistive behavior with a significantly enhanced relative electrical resistance change ΔR/R0 of 71.8 ± 7.1% at 5% strain. This value is much higher than those achieved in the PVDF-CNT (1–2 wt%) or PVDF-CB (3–4 wt%) composites (ΔR/R0 lower than 40%).

High-Loading Poly(ethylene glycol)-Blended Poly(acrylic acid) Membranes for CO2 Separation.

Poly(ethylene glycol) (PEG) is an amorphous material of interest owing to its high CO2 affinity and potential usage in CO2 separation applications. However, amorphous PEG often has a low molecular weight, making it challenging to form into the membrane. The crystalline high average molar mass poly(ethylene oxide) (PEO) cannot exhibit CO2 separation characteristics. Thus, it is crucial to employ low molecular weight PEG in high molecular weight polymers to increase the CO2 affinity for CO2 separation membranes. In this work, poly(acrylic acid) (PAA)/PEG blend membranes with a PEG-rich phase were simply fabricated by physical mixing with an ethanol solvent. The carbonyl group of the PAA and the hydroxyl group of the PEG formed a hydrogen bond. Furthermore, the thermal stability, glass transition temperature, and surface hydrophilicity of PAA/PEG blend membranes with various PEG concentrations were further characterized. The PAA/PEG(1:9) blend membrane exhibited an improved CO2 permeability of 51 Barrer with high selectivities relative to the other gas species (H2, N2, and CH4; CO2/H2 = 6, CO2/N2 = 63, CO2/CH4 = 21) at 35 °C and 150 psi owing to the enhanced CO2 affinity with the amorphous PEG-rich phase. These PAA/PEG blend membrane permeation characteristics indicate a promising prospect for CO2 capture applications.

In Situ Formation of Soft–Rigid Hybrid Fibers Decorated by Sparse Lamellae of PLLA: Achieving Ductile and Heat-Resistant Materials with High Strength

Constructing an oriented crystalline structure with high crystallinity in poly(l-lactide) (PLLA) is one efficient way to improve its mechanical strength, but flexibility is sacrificed because orderly arrangement restricts molecular mobility seriously. In this work, a unique hierarchical structure of soft–rigid hybrid fibers decorated by sparse lamellae of PLLA is in situ constructed successfully to improve mechanical strength and flexibility simultaneously. Through interfacial stereocomplexation between the PLLA matrix and poly(3-hydroxybutyrate-co-3-hydroxyvalerate)–poly(d-lactide) (PHBV-PDLA) copolymers, followed by a strong flow field during the multistage stretching extrusion (MSE), soft–rigid hybrid fibers of PHBV/interfacial stereocomplex crystallites (i-SCs) are formed to not only act as a reinforcement filler but also favor energy-dissipating deformation mechanisms. Moreover, under the coupling effect of hybrid fibers and intense flow field, the sparse PLLA lamella with a stiff shish is obtained. Consequently, nanofibrillar PLLA/PHBV-PDLA composites with a highly oriented structure exhibit high strength (94.1 MPa), considerable ductility (65.7%), and excellent heat resistance (E′140 °C > 310 MPa), compared to sea–island structured PLLA/PHBV-PDLA composites with an isotropic structure (59.3 MPa, 11.7%, and E′140 °C > 60 MPa). Furthermore, nanofibrillar PLLA/PHBV-PDLA composites can maintain ductility (57.7%) and strength (98.3 MPa) for 886 days at ambient temperature. The strengthening and toughening mechanisms based on the unique structure are proposed by investigating the microstructural changes before and after a tensile test. This work provides significant guidance for strong, ductile, and heat-resistant PLLA-based materials for durable applications.

Raman Snapshots of Side-Chain Dependent Polaron Dynamics in PolyThiophene Films.

Photogenerated polarons in π-conjugated polymers are the precursors to free charges at donor-acceptor interfaces. Unraveling the relationship between film morphology and polaron formation is conjectured to enable efficient charge generation in organic photovoltaic devices. However, it has been challenging to track the ultrafast dynamics of polarons selectively and thus evaluate the molecular coordinates that drive charge generation in films. Using a combination of broadband femtosecond transient absorption and resonance-selective femtosecond stimulated Raman spectroscopy, here, we investigate the polaron generation dynamics exclusively in traditional crystalline poly(3-hexylthiophene) (P3HT) and its amorphous side-chain variant poly(3-(2-ethylhexyl)thiophene-2,5-diyl) (P3EHT) films. The transient Raman data unequivocally provides evidence for an initial delocalization of the polaronic states via thiophene backbone planarization in ∼100 fs while capturing the subsequent morphology-dependent cooling dynamics in a few picoseconds. Our work highlights the structural significance of crystalline morphology in generating hot-charges and thereby emphasizes the importance of side-chain engineering in designing highly efficient conjugated polymer films for hot-carrier photovoltaic devices.

Particle dispersion system consisting of helically assembled liquid crystalline poly(para-phenylene)derivatives with reproducible chiroptical properties

A liquid crystalline poly(para-phenylene) derivative forms a helically π-stacked structure upon addition of a chiral binaphthyl compound, exhibiting blue circularly polarized luminescence.