Chiral polymer assemblies and methods for their preparation

Abstract

The application discloses a chiral polymer assembly and a preparation method thereof. The preparation method comprises the following steps: firstly, performing solvent-induced self-assembly on a non-chiral diacetylene monomer, and then performing ultraviolet topological polymerization to obtain a precursor solution containing polydiacetylene derivatives; then, a vortex field is applied to the precursor solution to induce the polydiacetylene derivatives to break symmetry and form a polymer assembly with chiral characteristics; and finally, the obtained chiral solution is gelled and fixed. The application takes a self-assembling polymer precursor system as a research object, introduces a rotating flow field induced symmetry breaking strategy into the polymer assembly system, and combines gel curing to realize stable locking of the flow field induced chiral structure, and a chiral polymer assembly with long-term stability is constructed.

Description

Technical Field

[0001] This invention relates to a chiral polymer assembly and its preparation method, belonging to the field of polymer synthesis technology. Background Technology

[0002] Addressing national strategic needs in high-performance optical devices, information functional materials, intelligent chemistry, and life sciences, developing green, efficient, and controllable new systems for constructing chiral polymers is of significant scientific value and practical importance for optimizing the structural design of functional chiral polymers and expanding their application scenarios. Around this goal, symmetry breaking, as the fundamental mechanism determining the generation, transmission, and amplification of chirality, has long been an important research topic in polymer chemistry, supramolecular chemistry, and materials chemistry.

[0003] Currently, the construction of chiral polymers mainly relies on strategies such as chiral monomers, chiral catalysts, or the addition of chiral inducers. While these methods can effectively construct chiral structures, they generally suffer from problems such as complex molecular design, high synthesis costs, and limited applicability to specific systems. In contrast, in completely achiral molecular systems, spontaneous symmetry breaking through molecular self-assembly and conformational evolution processes can induce the formation of chiral polymers. This not only helps deepen our understanding of the origin, transfer, and amplification mechanisms of chirality but also provides a new research paradigm for developing chiral polymer systems that are structurally simple, environmentally friendly, and have the potential for large-scale preparation.

[0004] However, since van't Hoff established the theory of stereochemistry in 1887, it has been clearly recognized that, under thermodynamic equilibrium conditions, mirror-image enantiomers are strictly equivalent in Gibbs free energy and enthalpy, and their ground state (S0) and excited states (S1 and T1) are both in an energy degenerate state. Therefore, achieving observable and stable symmetry breaking solely through the system itself in the absence of any chiral source is theoretically extremely challenging. Especially in polymer systems, due to their high degree of conformational freedom and significant statistical averaging effects, weak chiral biases are easily annihilated by thermal motion, making the formation of stable chiral structures even more difficult.

[0005] To overcome the limitations of thermodynamic equilibrium, researchers have increasingly focused on non-equilibrium systems in recent years, attempting to induce symmetry breaking through external environmental perturbations or continuous energy input. For example, environmental factors such as solvent evaporation, temperature gradients, and concentration fluctuations, as well as external stimuli such as light, heat, and electric fields, have all been shown to drive chiral selection behavior in systems under certain conditions. Among these, asymmetric eddy shear fields have attracted widespread attention due to their ubiquitous presence in nature and engineering systems. As a typical non-equilibrium driving force, eddy shear fields have been proposed as one of the potential physical mechanisms for the chiral origin of life in the cosmic environment, and are widely present in chemical reactions, materials processing, biological systems, and the natural environment.

[0006] From a fundamental science perspective, flow field perturbations generated by mechanical forces hold promise as a simple, green, and chiral external field that requires no additional chiral source, enabling the induction and regulation of chiral structures in molecules and polymer systems. In-depth research into the symmetry-breaking process driven by flow fields will not only help reveal the intrinsic laws governing the transmission of chiral information from macroscopic non-equilibrium force fields to the molecular and supramolecular scales, but also provide new theoretical basis and technical routes for the construction of chiral polymers under chiral source-free conditions, holding significant scientific importance and application prospects for the development of novel functional chiral materials. Summary of the Invention

[0007] The purpose of this invention is to provide a chiral polymer assembly and its preparation method. Taking a self-assembly polymer precursor system as the research object, the invention introduces a rotational flow field-induced symmetry breaking strategy into the polymer assembly system, and combines it with gel solidification to achieve stable locking of the flow field-induced chiral structure, thereby constructing a chiral polymer assembly with long-term stability.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A chiral polymer assembly is obtained by solvent-induced self-assembly of achiral diyne monomers, followed by ultraviolet topological polymerization, then vortex field-induced symmetry breaking to form a chiral structure, and finally gelation fixation.

[0009] Preferably, the structural formula of the non-chiral diyne monomer is: R1-CO-NH-L-NH-CO-CH=CH-Ar; Wherein, R1 is a C containing a conjugated diyne group. 10 -C 30 Straight-chain or branched alkyl groups; L stands for -(CH2) n - where n is any integer from 2 to 6; Ar represents substituted or unsubstituted aryl or pyridyl groups.

[0010] Preferably, in the structural formula of the non-chiral diyne monomer, R1 is CH3-(CH2). 11 -C≡CC≡C-(CH2)8-; L is -CH2-CH2-; Ar is pyridinyl.

[0011] The preparation method of any of the above-mentioned chiral polymer assemblies involves first performing solvent-induced self-assembly of a non-chiral diyne monomer, followed by ultraviolet topological polymerization to obtain a precursor solution containing polybutyne derivatives; then applying a vortex field to the precursor solution to induce symmetry breaking of the polybutyne derivatives, forming a polymer assembly with chiral characteristics; and finally gelling and fixing the obtained chiral solution.

[0012] Preferably, the method for preparing a non-chiral diyne monomer includes the following steps: S1. 3-(4-pyridyl)acrylic acid is activated in the presence of NHS and EDC·HCl to obtain 3-(4-pyridyl)acrylic acid NHS active ester; S2. Condensate 3-(4-pyridyl)acrylate NHS active ester with ethylenediamine to obtain an amino-terminated intermediate; S3. 10,12-diynetecosanoic acid is activated in the presence of NHS and DCC to obtain PCDA-NHS activated ester, which is then coupled with an amino-terminated intermediate.

[0013] Preferably, in step S1, the molar ratio of 3-(4-pyridyl)acrylic acid, NHS and EDC·HCl is 1:(1.0-1.2):(1.1-1.3), and the reaction temperature is 20-30℃; In step S2, the ratio of 3-(4-pyridyl)acrylate NHS active ester to ethylenediamine is 1 g:(6-9) mL, and the reaction is carried out under nitrogen protection at a temperature of 20-30℃. In step S3, the molar ratio of 10,12-diynetecosanoic acid, NHS and DCC is 1:(1.25-1.35):(1.4-1.5). The reaction is carried out under nitrogen protection at a temperature of 20-30℃ for 12-16 hours. The mass ratio of PCDA-NHS activated ester to amino-terminated intermediate is (0.6-0.8):(0.2-0.3); The coupling reaction was carried out in the presence of an acid-binding agent, which was triethylamine, at a reaction temperature of 20-30℃ for 12-16 hours.

[0014] Preferably, the specific preparation method of the precursor solution is to dissolve the non-chiral diyne monomer in dimethyl sulfoxide, add water dropwise under ultrasonic conditions, and after the addition is completed, sonicate at 70-90℃ for 20-40 min, cool to room temperature and let it stand for aging, seal and freeze at 1-5℃ in the dark for 10-15 h to obtain the diyne monomer assembly solution, and then irradiate under ultraviolet light (irradiation time preferably 5-15 min) to trigger the topological polymerization of the diyne monomer.

[0015] Preferably, the vortex field is generated by stirring, with a stirring speed of 100-1000 r / min, a stirring time of 1-60 min, and a stirring temperature of 10-30℃; the rotation direction of the vortex field is clockwise or counterclockwise.

[0016] Preferably, the gelation fixation method involves sequentially mixing borax solution and polyvinyl alcohol solution into a chiral solution and then allowing it to stand.

[0017] Preferably, the concentration of the borax solution is 0.1-0.15 g / mL, and the concentration of the polyvinyl alcohol solution is 0.01-0.03 g / mL; The volume ratio of borax solution, polyvinyl alcohol solution and chiral solution is (1.4-1.5):(2.5-3):1.

[0018] The beneficial effects of this invention are as follows: This invention constructs a polymer system capable of self-assembling into ordered nanostructures in an aqueous phase, and obtains structurally stable polydiyne assemblies through UV-induced polymerization. Furthermore, its chiral response behavior under an external mechanical rotating flow field is investigated. The results show that clockwise and counterclockwise stirring induce Cotton effect signals with opposite signs and mirror relationships, indicating that the rotating flow field can effectively drive the system to break mirror symmetry, inducing the polymer chains to form helical conformations with specific chiral preferences, thus achieving the transformation from an achiral system to a macroscopic chiral supramolecular structure.

[0019] Furthermore, by introducing a PVA / borax gel network to solidify the assembled structure, the fixation and preservation of the flow-induced chiral structure were successfully achieved. Even after external stirring stopped, the system maintained a stable circular dichroism (CD) signal, indicating that the formed chiral supramolecular structure was effectively locked and possessed good structural stability and chiral memory effect.

[0020] This invention effectively demonstrates that a mechanically rotating flow field can serve as an effective external physical stimulus to induce and amplify chirality in supramolecular systems. Furthermore, by combining gelation and photocrosslinking strategies, it enables long-term storage of chiral information, providing new research ideas for constructing tunable and immobilizable chiral supramolecular materials and exploring the origin and transmission mechanisms of chirality. This not only provides new experimental evidence for understanding the mechanisms of chirality generation and amplification in polymer systems under non-equilibrium conditions but also offers new research directions for developing green and efficient methods for constructing chiral polymers and novel functional chiral materials. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the synthesis of the diyne monomer DA-CAPD; Figure 2 The 1H NMR spectrum of the diyne monomer DA-CAPD; Figure 3 (a) Schematic diagram of DA-CAPD monomer polymerization, (b) Schematic diagram of stirring-induced chirality of polymer assemblies; Figure 4 The chiral response under different illumination polymerization durations; Figure 5 This describes the chiral expression induced by vortex stirring after the addition of PVA. Figure 6 This describes the chiral response during the switching between clockwise and counterclockwise stirring. Figure 7 To achieve chiral fixation through physical gelation; Figure 8 The stability of chiral fixation achieved through physical gelation. Detailed Implementation

[0022] Synthesis, purification and preparation of polybutyryl (PDA) precursors of diyne monomers.

[0023] The preparation of polybutyrylamide derivatives with pyridylacrylic acid photoresponsive groups in the side chain is divided into three steps: first, 3-(4-pyridyl)acrylic acid is activated by EDC / NHS; then, it is condensed with ethylenediamine to obtain an amino-terminated intermediate; finally, it is coupled with an NHS-activated ester of 10,12-diyneicosuccinic acid (PCDA) to construct the target functionalized diyrylamide monomer (e.g., Figure 1 (As shown). This monomer can be subsequently obtained through solvent-induced self-assembly and UV topological polymerization to yield conjugated polybutyrylene polymer, providing raw materials for subsequent chiral induction and fixation experiments.

[0024] Analytical grade reagents were used throughout the experiment, and all solvents were anhydrous before use. Key reactions were conducted under nitrogen protection to prevent oxidation of raw materials and side reactions. The main instruments included a 100mL round-bottom flask, a constant-pressure dropping funnel, a magnetic stirrer, a rotary evaporator, thin-layer chromatography (TLC) plates, a silica gel column chromatography apparatus, a vacuum drying oven, and a UV lamp.

[0025] Stepwise synthesis process.

[0026] Step 1: NHS activation of 3-(4-pyridyl)acrylic acid (preparation of active ester intermediate).

[0027] This step uses 3-(4-pyridyl)acrylic acid as a raw material. Under the catalysis of EDC·HCl and NHS (N-hydroxysuccinimide), the carboxyl group is converted into NHS active ester, which enhances the subsequent reaction activity with amino groups.

[0028] The reactants were added in the following proportions: 1.00 g (6.06 mmol) 3-(4-pyridyl)acrylic acid, 0.7489 g (6.51 mmol) NHS, and 1.3006 g (6.80 mmol) EDC·HCl. The three reactants were placed in a 100 mL round-bottom flask, and 20 mL of anhydrous dichloromethane was added as the reaction solvent in two 10 mL portions. The mixture was continuously stirred at 25 °C using a thermostatic magnetic stirrer. The reaction progress was monitored by TLC (thin-layer chromatography) using a mixture of ethyl acetate and petroleum ether as the developing solvent. The reaction endpoint was reached when the reactant spot completely disappeared at a volume ratio of 10:1.

[0029] After the reaction was complete, solid impurities in the system were removed by filtration. The filtrate was extracted multiple times with saturated brine and back-extracted multiple times with dichloromethane. The organic phases were combined. The organic phase was dried with anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure to obtain the 3-(4-pyridyl)acrylate NHS active ester intermediate. This product should be stored in a sealed container protected from light and immediately used in the next reaction step.

[0030] Step 2: Condensation of the active ester with ethylenediamine (preparation of an amino-terminated intermediate).

[0031] The 3-(4-pyridyl)acrylate NHS active ester prepared in the first step is subjected to an amidation reaction with ethylenediamine to introduce a terminal amino group, providing a reaction site for subsequent coupling with PCDA derivatives.

[0032] Dissolve 1 g of the 3-(4-pyridyl)acrylate NHS active ester obtained in the first step in 10 mL of anhydrous dichloromethane and transfer it to a constant pressure dropping funnel. Separately, take a 100 mL round-bottom flask, add 8 mL of ethylenediamine and 10 mL of anhydrous dichloromethane, and stir until homogeneous. Under nitrogen protection at room temperature, slowly add the active ester solution dropwise to the ethylenediamine solution, stirring continuously during the addition process. During the reaction, the solution gradually changes from colorless to pale yellow, then to yellow, and finally becomes turbid.

[0033] The reaction was monitored by TLC, with a mixture of ethyl acetate and petroleum ether in a volume ratio of 5:1 as the developing solvent. The reaction was terminated when the starting material spot disappeared and the target product spot appeared. The reaction solution was washed with saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation under reduced pressure to obtain a pale yellow, viscous, amino-terminated intermediate. This intermediate did not require further purification and was used directly in the third step of the reaction.

[0034] Step 3: Couple PCDA-NHS activated ester with amino intermediate (synthesis of target diyne monomer).

[0035] First, PCDA-NHS activated ester was prepared with the following feed ratio: 1.0 g (2.67 mmol) 10,12-diyneicosuccinic acid, 0.40 g (3.47 mmol) NHS, and 0.80 g (3.88 mmol) DCC (N,N'-dicyclohexylcarbodiimide). The three feedstocks were added to a 100 mL round-bottom flask, followed by 10 mL of anhydrous dichloromethane. The reaction was carried out overnight at room temperature under nitrogen protection. After the reaction, the white precipitate was removed by filtration. The solvent was removed by rotary evaporation under reduced pressure. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and methanol, with the volume ratio gradually adjusted from 10:1 to 5:1. The target fraction was collected, evaporated to dryness, and then vacuum dried to obtain a white solid PCDA-NHS activated ester.

[0036] 0.3 g of the amino-terminated intermediate prepared in the second step was dissolved in 10 mL of anhydrous dichloromethane, and 5 g of triethylamine was added as an acid-binding agent. The mixture was stirred thoroughly under nitrogen protection. 0.73 g of the PCDA-NHS activated ester was dissolved in 5 mL of anhydrous dichloromethane and slowly added dropwise to the intermediate solution. The reaction was carried out overnight at room temperature. The reaction was monitored by TLC, with a mixture of dichloromethane and methanol in a volume ratio of 5:1 as the developing solvent, until the starting material spots disappeared.

[0037] After the reaction, the precipitate in the system was removed by filtration. The filtrate was washed successively with saturated brine and deionized water. The organic phase was dried with anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure to obtain a pale yellow crude product. The crude product was further purified by silica gel column chromatography with an eluent ratio of dichloromethane:methanol = 7:1 (v / v). The target fraction was collected, evaporated to dryness, and placed in a vacuum drying oven for drying in the dark to obtain a white solid target diyne monomer DA-CAPD (total yield, approximately 35.0%). NMR characterization was as follows. Figure 2 As shown, the target product has been correctly synthesized.

[0038] Self-assembly of diyne monomers and preparation of polybutadiene precursors.

[0039] The synthesized target diyne monomer was dissolved in dimethyl sulfoxide to prepare a solution with a concentration of 1.0 mg / mL. Under continuous sonication, 15 mL of deionized water was added dropwise at a controlled dropping rate of 1 mL / min to avoid disordered aggregation due to excessively high local concentrations. After the addition was complete, the system was placed in an 80℃ isothermal sonicator for another 30 minutes to promote intermolecular hydrogen bonding and π-π stacking, forming an ordered pre-assembled structure.

[0040] Turn off the ultrasonic equipment and allow the system to cool naturally to room temperature. Let it stand for 1 hour to complete the initial curing. Seal the container opening with sealing film and place it in a 4°C refrigerator in the dark for 12 hours to obtain a stable diyne monomer assembly solution. Dispense the assembly solution into standard cuvettes and irradiate them under a 254nm UV lamp to trigger topological polymerization of the diyne monomer, generating a conjugated polybutyne backbone. The resulting solution is the precursor solution for the polybutyne derivative and can be directly used for subsequent experiments.

[0041] Chiral induction experiment of magnetic stirring vortex field.

[0042] Take 0.55 mL of the diyne monomer assembly solution, irradiate it under a 254 nm UV lamp for polymerization, then dispense it into several cuvettes, add 1.5 mL of deionized water, place a uniform stir bar in each cuvette, and center the reaction flask on a magnetic stirrer. Take another equal portion of the solution and let it stand without stirring as a blank control group.

[0043] Experiment on variable stirring direction: Stirring speed (500 r / min), stirring time (3 min), and stirring temperature (25℃) were set into two stirring modes, clockwise (CW) and counterclockwise (CCW), respectively, to complete the vortex field induction.

[0044] Stirring speed variable experiment: In clockwise and counterclockwise modes, the stirring speed gradients were set to 100 r / min, 150 r / min, 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min, 550 r / min, 600 r / min, 800 r / min and 1000 r / min respectively. The stirring time (3 min) and stirring temperature (25℃) were fixed, and the induction experiment was carried out in sequence.

[0045] Irradiation duration variable experiment: The polymerization under 254 nm UV lamp was set to irradiation time of 1 min, 2 min, 3 min, 5 min, 8 min, 12 min and 20 min in sequence. The assemblies obtained with different polymerization times were used to carry out induction experiments (with fixed stirring speed (500 r / min) and stirring time (3 min) and stirring temperature (25℃)).

[0046] Alternating stirring direction experiment: The same batch of chiral PDA samples were subjected to alternating clockwise (CW) and counterclockwise (CCW) stirring modes to complete the induction experiment.

[0047] Chiral structure fixation experiment - physical gelation fixation.

[0048] The induced chiral solution (0.55 mL) was transferred to a cuvette. Under stirring, 0.8 mL of borax solution (0.12 g / mL) and 1.5 mL of polyvinyl alcohol solution (0.02 g / mL) were added sequentially. After the addition was complete, stirring was stopped and the mixture was allowed to stand for 30 min. A three-dimensional physical gel network was formed by intermolecular hydrogen bonds, π-π stacking, and hydrophilic-hydrophobic interactions, thereby freezing the orientation of the chiral molecules.

[0049] Stability tests were conducted on gel samples at room temperature and pressure. Samples were taken at set time intervals, and the attenuation of chiral signals was detected using CD spectroscopy.

[0050] Characterization testing methods.

[0051] Circular dichroism (CD): Detects all experimental and control group samples, records characteristic peak positions, signal intensity, and signal sign, and determines chirality type, chirality intensity, and structural stability.

[0052] Ultraviolet-visible spectroscopy (UV-Vis): Monitor the conjugated backbone structure of PDA and track the reaction process of 254nm polymerization and 365nm photocrosslinking / photodecrosslinking.

[0053] Nuclear magnetic resonance (NMR): Used only for the diacetylene monomer stage to characterize the monomer molecular structure and purity.

[0054] Experimental results.

[0055] This section combines circular dichroism (CD) and ultraviolet-visible (UV-Vis) spectroscopy characterization data to analyze the experimental results of vortex field induction, additive modification, physical fixation, chemical crosslinking, reversible chiral switching, and blank control in sequence. No chemical chiral source was added throughout the process, and all chiral signals were generated by magnetic stirring vortex field.

[0056] Results of experiments induced by a simple vortex field (vortex-induced).

[0057] See Figure 3 As shown, this group, in a pure water system, induced chirality in PDA assemblies solely through a magnetic stirring vortex field, without adding any additives or fixatives. The CD spectrum exhibits typical Cotton effect characteristic peaks, demonstrating that the shear and torsional forces generated by the vortex field can break the disordered arrangement of PDA molecular chains, achieving supramolecular system symmetry breaking and successfully inducing chirality in achiral polymer assemblies. Comparing the clockwise (CW) and counterclockwise (CCW) stirring groups, the CD signals of the two groups are opposite in sign, indicating that the stirring rotation direction directly determines the left-handed or right-handed chiral configuration of the assembly. In this pure solution state, the molecular chains have high degrees of freedom, and the chiral orientation induced by the vortex is a transient structure. Continuous monitoring revealed that the CD signal slowly decayed over time during static incubation at room temperature, indicating that the chiral structure obtained solely by vortex field induction has poor stability and cannot maintain chiral characteristics for a long time; once stirring stops, the chiral signal intensity immediately disappears.

[0058] Experiment on the variable of illumination duration.

[0059] like Figure 4 As shown, with the extension of the 254nm light irradiation polymerization time, the chiral signal expression of the polybutadiene derivative assembly solution gradually increased during the continued stirring induction (500r / min, 25℃, 3min), and reached its maximum value after the polymerization time reached 8min. However, further extending the light irradiation polymerization time would lead to a partial attenuation of the chiral signal.

[0060] Experimental results of adding PVA to thicken the system (adding PVA increases viscosity).

[0061] Place 0.55 mL of the polybutadiene derivative precursor solution in a cuvette, and slowly add 1.5 mL of polyvinyl alcohol solution (0.02 g / mL). Maintain the same experimental conditions as the pure vortex-induced group. See [link to cuvette]. Figure 5As shown, compared to the pure vortex-induced group, the CD characteristic peak positions of this group of samples did not change, and the chiral configuration remained unchanged, but the chiral signal peak shape was significantly smoother. This is because PVA increases the system viscosity, effectively suppressing the random thermal motion of PDA molecular chains, prolonging the directional effect of the vortex field on the molecular chains, and enhancing the ordered packing of molecules. This system still did not construct a cross-linked network, and the molecular chains still possessed a certain migration ability. The chiral signal decay rate was slower than that of the pure water system, but once stirring was turned off, the chiral signal gradually disappeared.

[0062] Results of experiments involving alternating clockwise and counterclockwise stirring (switch between clockwise and counterclockwise stirring to change chirality).

[0063] The reversible controllability of the vortex field on the chiral configuration was investigated by alternately switching between clockwise and counterclockwise stirring directions on the same batch of chiral PDA samples. (See also...) Figure 6 As shown, the CD data intuitively demonstrates the reversible chirality conversion law: after switching the stirring direction, the sample CD signal flips synchronously between positive and negative, and the interconversion between left-handed and right-handed chirality can be completed quickly. After multiple cycles of alternating stirring, the characteristic peak morphology and signal intensity show no significant disturbance, and the cycle stability is good. The results confirm that the stirring direction can act as a reversible chirality switch, and this system has excellent dynamic control capability.

[0064] Experimental results of physical gelation fixation of PVA and borax (PVA + borax, gelation fixation of chiral).

[0065] A three-dimensional physical gel network was constructed using a PVA and borax compound, utilizing intermolecular hydrogen bonds, π-π stacking, and hydrophilic-hydrophobic interactions, to physically immobilize the vortex-induced chiral structure. (See also...) Figure 7 As shown, the CD spectrum indicates that the gel sample completely retains the original chiral characteristic peaks, and the chiral type is completely consistent with the induction stage. The spatial confinement network formed by the physical gel effectively restricts the migration and flipping of PDA segments, significantly reducing the rate of chiral signal decay. Even with stirring turned off, the chiral structure can remain stable for a long time at room temperature and pressure (e.g., Figure 8 As shown, the chiral structure remained stable after being placed at room temperature and pressure for 10 minutes.

[0066] In summary, this invention focuses on butyrylene monomers with terminal pyridine groups to construct a polymer system capable of self-assembling into ordered nanostructures in an aqueous phase. Stable polydiyrylene assemblies were obtained through 254 nm UV-induced polymerization, and their chiral response behavior under external mechanical rotating flow field was further investigated.

[0067] The results show that clockwise and counterclockwise stirring induces Cotton effect signals with opposite signs and mirror relationships, respectively. This indicates that the rotating flow field can effectively drive the system to break mirror symmetry, induce polymer chains to form helical conformations with specific chirality preferences, and realize the transformation from achiral system to macroscopic chiral supramolecular structure.

[0068] Furthermore, by introducing a PVA / borax gel network to solidify the assembled structure, the fixation and preservation of the flow-induced chiral structure were successfully achieved. Even after external stirring stopped, the system maintained a stable circular dichroism (CD) signal, indicating that the formed chiral supramolecular structure was effectively locked and possessed good structural stability and chiral memory effect.

[0069] This invention demonstrates that a mechanically rotating flow field can serve as an effective external physical stimulus to induce and amplify the chirality of supramolecular systems. Furthermore, by combining gelation and photocrosslinking strategies, long-term storage of chiral information can be achieved, providing new research ideas for constructing tunable and immobilizable chiral supramolecular materials and exploring the origin and transmission mechanisms of chirality.

Claims

1. A chiral polymer assembly, characterized in that, It is obtained by solvent-induced self-assembly of non-chiral diyne monomers, ultraviolet topological polymerization, followed by symmetry breaking induced by vortex field to form a chiral structure, and then gelation fixation.

2. The chiral polymer assembly according to claim 1, characterized in that, The structural formula of the non-chiral diyne monomer is: R1-CO-NH-L-NH-CO-CH=CH-Ar; Wherein, R1 is a C containing a conjugated diyne group. 10 -C 30 Straight-chain or branched alkyl groups; L stands for -(CH2) n - where n is any integer from 2 to 6; Ar represents substituted or unsubstituted aryl or pyridyl groups.

3. The chiral polymer assembly according to claim 2, characterized in that, In the structural formula of a non-chiral diyne monomer, R1 is CH3-(CH2). 11 -C≡CC≡C-(CH2)8-; L is -CH2-CH2-; Ar is pyridinyl.

4. The method for preparing the chiral polymer assembly according to any one of claims 1-3, characterized in that, The process involves first solvent-induced self-assembly of achiral diyne monomers followed by ultraviolet topological polymerization to obtain a precursor solution containing polybutyne derivatives. Then, a vortex field is applied to the precursor solution to induce symmetry breaking of the polybutyne derivatives, forming a polymer assembly with chiral characteristics. Finally, the resulting chiral solution is gelled and fixed.

5. The method for preparing the chiral polymer assembly according to claim 4, characterized in that, The preparation method of non-chiral diyne monomers includes the following steps: S1. 3-(4-pyridyl)acrylic acid is activated in the presence of NHS and EDC·HCl to obtain 3-(4-pyridyl)acrylic acid NHS active ester; S2. Condensate 3-(4-pyridyl)acrylate NHS active ester with ethylenediamine to obtain an amino-terminated intermediate; S3. 10,12-diynetecosanoic acid is activated in the presence of NHS and DCC to obtain PCDA-NHS activated ester, which is then coupled with an amino-terminated intermediate.

6. The method for preparing the chiral polymer assembly according to claim 5, characterized in that, In step S1, the molar ratio of 3-(4-pyridyl)acrylic acid, NHS and EDC·HCl is 1:(1.0-1.2):(1.1-1.3), and the reaction temperature is 20-30℃; In step S2, the ratio of 3-(4-pyridyl)acrylate NHS active ester to ethylenediamine is 1 g:(6-9) mL, and the reaction is carried out under nitrogen protection at a temperature of 20-30℃. In step S3, the molar ratio of 10,12-diynetecosanoic acid, NHS and DCC is 1:(1.25-1.35):(1.4-1.5). The reaction is carried out under nitrogen protection at a temperature of 20-30℃ for 12-16 hours. The mass ratio of PCDA-NHS activated ester to amino-terminated intermediate is (0.6-0.8):(0.2-0.3); The coupling reaction was carried out in the presence of an acid-binding agent, which was triethylamine, at a reaction temperature of 20-30℃ for 12-16 hours.

7. The method for preparing the chiral polymer assembly according to claim 4, characterized in that, The specific preparation method of the precursor solution is to dissolve the non-chiral diyne monomer in dimethyl sulfoxide, add water dropwise under ultrasonic conditions, and after the addition is completed, sonicate at 70-90℃ for 20-40 min, cool to room temperature and let it stand for aging, seal and freeze at 1-5℃ in the dark for 10-15 h to obtain the diyne monomer assembly solution, and then irradiate under ultraviolet light to trigger the diyne monomer to undergo topological polymerization.

8. The method for preparing the chiral polymer assembly according to claim 4, characterized in that, The vortex field is generated by stirring, with a stirring speed of 100-1000 r / min, a stirring time of 1-60 min, and a stirring temperature of 10-30℃; the rotation direction of the vortex field is clockwise or counterclockwise.

9. The method for preparing the chiral polymer assembly according to claim 4, characterized in that, The gelation fixation method involves sequentially mixing borax solution and polyvinyl alcohol solution into a chiral solution and then allowing it to stand.

10. The method for preparing the chiral polymer assembly according to claim 9, characterized in that, The concentration of borax solution is 0.1-0.15 g / mL, and the concentration of polyvinyl alcohol solution is 0.01-0.03 g / mL; The volume ratio of borax solution, polyvinyl alcohol solution and chiral solution is (1.4-1.5):(2.5-3):1.

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