Side-chain Poly Research Articles

Dynamics of side chains in poly(quinoxaline-2,3-diyl)s studied via quasielastic neutron scattering.

The side chain dynamics of poly(quinoxaline-2,3-diyl)s (PQXs) are expected to influence their conformation. To investigate these dynamics experimentally, quasielastic neutron scattering (QENS) was performed for PQXs in deuterated tetrahydrofuran (THF-d8) and deuterated 1,1,2-trichloroethane/THF (1,1,2-TCE-d3/THF-d8), in which they formed right-handed and left-handed helical structures, respectively. The mean-square displacement of the PQX side chains in 1,1,2-TCE-d3/THF-d8 was lower than that in THF-d8. Furthermore, QENS complementary studies and molecular dynamics simulations unraveled a coupling between the main-chain and side chain dynamics of PQXs, suggesting the possibility of controlling the main-chain helical chirality through the dynamics of chiral side chains. These insights present a novel strategy for the design of synthetic helical macromolecules with precise chirality control.

Tuning poly(isatin biphenyl) anion exchange membranes by copolymerization and branching

The cardo structure and long side chain of poly(isatin biphenyl) are conducive to the motion and aggregation of cations over mainchain type membranes, therefore it is used as the pristine membrane. It is well known that random copolymerization and branching can effectively modify the configuration and properties of polymers. Herein, we use random copolymerization and branching to improve the behaviors of poly(isatin biphenyl) anion exchange membranes (AEMs). High-curvature random copolymers (QPIDBP-n) and high free volume branched polymers (b-QPIBP-x) are synthesized via polycondensation. The random copolymerization results in the formation of a twisted chain structure, while the introduction of branching agent leads to the formation of orderly stacking of chains. Both of these approaches have been demonstrated to boost the microphase-separated morphology of the pristine polymer. A series of QPIDBP-n and b-QPIBP-x are tested and an optimal ratio is explored. QPIDBP-40 and b-QPIBP-5 exhibit high overall performance. Among the as-prepared membranes, b-QPIBP-5 exhibits the highest conductivity (80 °C, 160.7 mS cm−1) with a swelling ratio of 20.7 %. The residual conductivity of b-QPIBP-5 is 93.1 % after the 1200 h alkali stability test. The cell assembled by b-QPIBP-5 achieves a peak power density of 680 mW cm−2. Moreover, the b-QPIBP-5 based cell holds 88.6 % voltage after the in-situ stability test for 50 h.

IRDye 700DX-conjugated polymers inducing photochemical internalization

SignificancePhotochemical internalization (PCI) is a promising technique to exert therapeutic potency of biopharmaceutics in a light-selective manner, and its endowment of selectivity to a specific molecule will broaden its application. This study reports αvβ3-targeted PCI of nucleic acids by the use of functional polymers modified with IRDye 700DX and cyclic RGD (cRGD) peptides. ApproachThe functional polymers were constructed by conjugating multiple cRGD peptides with the side chains of poly(ethylene glycol)-poly(L-glutamic acid) and subsequent introduction of IRDye 700DX at the α-end. ResultsThe functional polymers having multiple cRGD peptides exhibited specificity to αvβ3 integrins and selective accumulation within target tumors upon intravenous injection. Importantly, the polymer having the appropriate number of cRGD peptides induced efficient PCI. ConclusionsThis study revealed that IRDye 700DX can be utilized for PCI and that the efficiency was critically affected by the delivery systems.

Preparation of trastuzumab-DM1 conjugate with a high drug-to-antibody ratio for breast cancer therapy

Antibody-drug conjugates (ADCs) are important in active tumor-targeting therapy. However, improving the efficiency of payload delivery to tumors without affecting the tumor-targeting ability of the antigen-binding fragment (Fab) structure remains a challenge. In this study, a Fab-nondestructive ADC loaded with maytansine (DM1) (T-NPLG-DM135) was prepared with drug-to-antibody ratio (DAR) of up to 35 by utilizing the carboxyl groups on the side-chain of poly(L-glutamic acid) (PLG) as the payload binding sites. The use of the Fc-III-4C peptide and the preparation condition of aqueous environment were conducive to avoiding the impact of the Fab structure of monoclonal antibodies on tumor-targeting capability. T-NPLG-DM135 was recognized and rapidly internalized by HER2-expressing SKBR-3 tumor cells, with a 3.8-fold increase in accumulation compared to that of the non-tumor-targeting IgG-NPLG-DM135. T-NPLG-DM135 also showed excellent tumor inhibition and its therapeutic effect improved as the DAR increased. The successful development of T-NPLG-DM135 demonstrates the potential of this approach for future ADC design and development.

Side-chain Poly[2]pseudorotaxanes containing β-cyclodextrin for more sustainable tanning process

Sustainability of leather lies in how the hide, a sustainable, naturally renewable, raw material, is processed. Tanning chemistry has been a limiting factor for leather sustainability. In this study, a host-guest synthesis strategy was selected to modify one of the most widely used tanning polymer, MIDA DD, and obtain a new hybrid tanning system containing β-cyclodextrin, and leather drastically less impactful on the earth and people. Poly[2]pseudorotaxane Side-Chain Complexes (PSCCs) have been obtained by threading β-cyclodextrin units onto the side-chains of the commercial MIDA DD. The formation of PSCCs in aqueous solution was investigated by using 1D NMR, ATR-FTIR and TGA experiments. The ability of PSCCs to stabilize the collagen matrix was tested at laboratory and industrial pilot scale by micro-DSC, ATR-FTIR and solid-state NMR techniques. The physical and mechanical performance of the obtained crust leather was determined by standard tests used in tanning industry. Side-chain poly[2]pseudorotaxanes showed better tanning performances than the fossil-based MIDA DD, the most effective supramolecular tannins being obtained by mixing β-CD and MIDA DD in ratios close to 1/1 (w/w). The new tanning mixtures allow for significantly reducing both the amount of fossil-based MIDA-DD polymer in the current tanning processes (by 45%) and the free bisphenol content in leather crust (by more than 80%) due to the presence of bio-based β-CD in the composition of the new supramolecular tanning agents. The findings disclosed here pave the way for the CDs’ employment in improving the sustainability of tanning processes.

Facial amphiphilic naphthoic acid-derived antimicrobial polymers against multi-drug resistant gram-negative bacteria and biofilms

Inspired by the facial amphiphilic nature and antimicrobial efficacy of many antimicrobial peptides, this work reported facial amphiphilic bicyclic naphthoic acid derivatives with different ratios of charges to rings that were installed onto side chains of poly(glycidyl methacrylate). Six quaternary ammonium-charged (QAC) polymers were prepared to investigate the structure-activity relationship. These QAC polymers displayed potent antibacterial activity against various multi-drug resistant (MDR) gram-negative pathogens such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. Polymers demonstrated low hemolysis and high antimicrobial selectivity. Additionally, they were able to eradicate established biofilms and kill metabolically inactive dormant cells. The membrane permeabilization and depolarization results indicated a mechanism of action through membrane disruption. Two lead polymers showed no resistance from MDR-P. aeruginosa and MDR-K. pneumoniae. These facial amphiphiles are potentially a new class of potent antimicrobial agents to tackle the antimicrobial resistance for both planktonic and biofilm-related infections.

Altering the bio-inert properties of surfaces by fluorinated copolymers of mPEGMA

Hydrophilic materials display “bio-inert properties”, meaning that they are less recognized as foreign substances by proteins and cells. Such materials are often water soluble; therefore, one general approach to enable the use of these materials in various applications deals with copolymerizing hydrophilic monomers with hydrophobic ones to facilitate such resulting copolymers water insoluble. However, reducing the hydrophilic monomer amount may reduce the bio-inert properties of the material. The decrease in bio-inert properties can be avoided when small amounts of fluorine are used in copolymers with hydrophilic monomers, as presented in this article. Even in small quantities (7.9 wt%), the fluorinated monomer, 1,1,1,3,3,3-hexafluoropropan-2-yl 2-fluoroacrylate (FAHFiP), contributed to the improved hydrophobicity of the polymers of the long side-chain poly(ethylene glycol) methyl ether methacrylate (mPEGMA) bearing nine ethylene glycol units turning them water insoluble. As evidenced by the AFM deformation image, a phase separation between the FAHFiP and mPEGMA domains was observed. The copolymer with the highest amount of the fluorinated monomer (66.2 wt%) displayed also high (82 %) FAHFiP amount at the polymer–water interface. In contrast, the hydrated sample with the lowest FAHFiP/highest mPEGMA amount was enriched of three times more hydrophilic domains at the polymer–water interface compared to that of the sample with the highest FAHFiP content. Thus, by adding a small FAHFiP amount to mPEGMA copolymers, water insoluble in the bulk too, could be turned highly hydrophilic at the water interface. The high content of intermediate water contributed to their excellent bio-inert properties. Platelet adhesion and fibrinogen adsorption on their surfaces were even more decreased as compared to those on poly(2-methoxyethyl acrylate), which is typically used in medical devices.

Synthesis and characterization of silk-poly(guluronate) hybrid polymers for the fabrication of dual crosslinked, mechanically dynamic hydrogels

The rapid ionic crosslinking of alginate has been actively studied for biomedical applications including hydrogel scaffolds for tissue engineering, injectable gels, and 3D bioprinting. However, the poor structural stability of ionic crosslinks under physiological conditions limits the widespread applications of these hydrogels. Moreover, the lack of cell adhesion to the material combined with the inability of proteases to degrade alginate further restrict utility as hydrogel scaffolds. Blends of alginate with silk fibroin have been proposed for improved structural and mechanical properties, but potential phase separation between the hydrophobic protein and the hydrophilic polysaccharide remains an issue. In this study, we demonstrated the synthesis of a hybrid biopolymer composed of a silk backbone with side chains of poly(guluronate) isolated from alginate to introduce rapid ionic crosslinking on enzymatically crosslinked silk-based hydrogels for on-demand and reversible stiffening and softening properties. Dual crosslinked macro- and microgels of silk fibroin-poly(guluronate) (SF-PG) hybrid polymers displayed dynamic morphology with reversible shrinking and swelling behavior. SF-PG hydrogel discs demonstrated dynamic mechanics with compressive moduli ranging from less than 5 kPa to over 80 kPa and underwent proteolytic degradation unlike covalently crosslinked alginate controls. SF-PG gels supplemented with gelatin substituted with tyramine or both tyramine and PG also supported the attachment and survival of murine fibroblasts, suggesting potential uses of these new hydrogels in mammalian cell culture to investigate cellular responses to dynamic mechanics or modeling of diseases defined by matrix mechanics, such as fibrosis and cancer.

Unimolecular Micelles from Randomly Grafted Arborescent Copolymers with Different Core Branching Densities: Encapsulation of Doxorubicin and In Vitro Release Study

A series of amphiphilic arborescent copolymers of generations G1 and G2 with an arborescent poly(γ-benzyl L-glutamate) (PBG) core and poly(ethylene oxide) (PEO) chain segments in the shell, PBG-g-PEO, were synthesized and evaluated as drug delivery nanocarriers. The PBG building blocks were generated by ring-opening polymerization of γ-benzyl L-glutamic acid N-carboxyanhydride (Glu-NCA) initiated with n-hexylamine. Partial or full deprotection of the benzyl ester groups followed by coupling with PBG chains yielded a comb-branched (arborescent polymer generation zero or G0) PBG structure. Additional cycles of deprotection and grafting provided G1 and G2 arborescent polypeptides. Side chains of poly(ethylene oxide) were then randomly grafted onto the arborescent PBG substrates to produce amphiphilic arborescent copolymers. Control over the branching density of G0PBG was investigated by varying the length and the deprotection level of the linear PBG substrates used in their synthesis. Three G0PBG cores with different branching densities, varying from a compact and dense to a loose and more porous structure, were thus synthesized. These amphiphilic copolymers behaved similar to unimolecular micelles in aqueous solutions, with a unimodal number- and volume-weighted size distributions in dynamic light scattering measurements. It was demonstrated that these biocompatible copolymers can encapsulate hydrophobic drugs such as doxorubicin (DOX) within their hydrophobic core with drug loading efficiencies of 42-65%. Sustained and pH-responsive DOX release was observed from the unimolecular micelles, which suggests that they could be useful as drug nanocarriers for cancer therapy.

Understanding of hydroxide transport in poly(arylene indole piperidinium) anion exchange membranes: Effect of side-chain position

The introduction of long side chains to improve hydroxide transport in anion exchange membranes (AEMs) is a common strategy. However, the mechanism of the effect of side-chain position on hydroxide transport in the currently emerging poly(arylene indole piperidinium) AEMs remains unclear. Molecular dynamics simulation was performed to investigate the effect of the side-chain position on hydroxide transport. Three typical long side-chain poly(arylene indole piperidinium) AEMs were constructed, which were tadpole-chain type (t-PITPC10), pendant-chain type (p-PITPC10), and side chains attached onto the backbone separated from cationic groups type (a-PITPC10). The simulation results suggest that the self-diffusion coefficients of hydroxide follow the order: t-PITPC10 < p-PITPC10 < a-PITPC10 at the same hydration number. The strong interaction between the hydrophobic indole groups and hydroxides in t-PITPC10 and p-PITPC10 hinders the efficient transport of hydroxide. In contrast, this interaction is weaker in a-PITPC10 due to side chains being connected at indole groups. The overlapping region of the hydration shell around adjacent cationic groups is larger in a-PITPC10. Meanwhile, the connected aqueous phase and ion transport channels in a-PITPC10 promote hydroxide transport. Hence, the AEM with side chains attached onto the backbone separated from cationic groups (a-PITPC10) is superior to the AEMs with side chains linked to cationic groups (t-PITPC10 and p-PITPC10) in the improvement of hydroxide transport.

Effects of hydrophobic side chains in poly(fluorenyl-co-aryl piperidinium) ionomers for durable anion exchange membrane fuel cells

Hydrophobic side chain grafted poly(fluorenyl-co-aryl piperidinium) ionomers simultaneously possess outstanding peak power density of 2.6 W cm−2 at 80 °C along with durable in situ stability of 0.4 mV h−1 voltage decay rate under 0.6 A cm−2 at 70 °C.

Development of rigid side-chain poly(ether sulfone)s based anion exchange membrane with multiple annular quaternary ammonium ion groups for fuel cells

A variety of poly (ether sulfone)s based anion exchange membranes (AEMs) rPES(x/y)-Q with high-density heterocyclic quaternary ammonium groups is prepared by a polycondensation of novel difluoro monomer with biphenol and bis(4-fluorophenyl) sulfone. The AEMs rPES(x/y)-Q exhibit low IEC values in the range of 0.82–1.33 mequiv. g−1 but relatively high hydroxide conductivity of 54.1–82.3 mS cm−1 at 80 °C. Moreover, the AEMs rPES(x/y)-Q display affordable water uptake and good stability due to their rigid side-chain, high-density and stable heterocyclic quaternary ammonium cations. Noticeably, the rPES(5/20)-MPy based single fuel cell displays a large maximum power density of 141 mW cm−2, which reveals a potential application in anion exchange membrane fuel cell.

A polybromide confiner with selective bromide conduction for high performance aqueous zinc-bromine batteries

Aqueous zinc-bromine batteries are promising energy storage systems. The non-flow setup largely reduces the cost, and the application of Br− containing electrolytes transform the volatile charged product Br2 to polybromide. However, the shuttling of soluble polybromide species causes poor coulombic efficiency and corrosion of the negative electrode. Herein, we design a composite positive electrode of polybromide confiner and conductive agent for non-flow zinc-bromine batteries. The (2-bromoethyl) trimethylammonium bromide and hexyl bromide are grafted as the side chains of poly(biphenyl pyridine). The obtained PBP-BTAB-HB polymer provides selective bromide conduction whereas hinders polybromide diffusion through steric hindrance. It forms uniform layer on the Super P carbon particles, resulting in the composite electrode with facile electron and bromide transports as well as polybromide restriction. In the aqueous zinc-bromine battery, the positive electrode presents high coulombic, voltage and energy efficiencies of 92%, 81% and 74%, respectively, at 8 mA cm−2 with 2 mAh cm−2 charge capacity. Stable cycling is achieved for 1200 cycles with 99.8% capacity retention. The high electrochemical performance is preserved at a low temperature of 0 °C. A pouch cell is also demonstrated, delivering 18 mAh capacity at 100 mA. Our work offers a promising path for high-performance zinc-bromine batteries.

Tumor-Selective Cascade-Amplified Dual-Prodrugs Activation for Synergistic Oxidation-Chemotherapy

Tumor-Selective Cascade-Amplified Dual-Prodrugs Activation for Synergistic Oxidation-Chemotherapy

Impact of side-chains in poly(dibenzyl-co-terphenyl piperidinium) copolymers for anion exchange membrane fuel cells

Anion exchange membrane fuel cells (AEMFCs) have experienced rapid advancement in the past few years due to the discovery of high-performance AEMs and ionomers. Here, we report a series of side-chain-type poly(dibenzbeyl-co-terphenyl piperidinium) ( s -PDTP) copolymers as ionomers and membranes for AEMFC applications. The features of aryl ether-free PDTP polymer backbone and pendent ammonium groups endow both high alkaline stability and excellent micromorphology to s -PDTP copolymers. These ion-exchange-capacity (IEC)-controlled s -PDTP membranes possess high OH − conductivity >120 mS cm −1 at 80 °C, reasonable molecular weight (M w = 150–290 kDa), and excellent ex-situ durability in 1 M NaOH at 80 °C for 1000 h (∼90% conductivity remaining). For ionomer research, s -PDTP ionomers with moderate IEC (∼3.0 mmol g −1 ) and rational water uptake (∼200%) exhibit optimal AEMFC performance based on a PDTP membrane compared to high-IEC or low-IEC s -PDTP ionomers (>3.4 mmol g −1 or <2.4 mmol g −1 ). Based on Pt/C, s -PDTP-based AEMFCs reach a peak power density (PPD) of 1.47 W cm −2 in H 2 –O 2 and 1.04 W cm −2 in H 2 -air (CO 2 -free) at 80 °C. • IEC-controlled side-chain-type poly(aryl-co-aryl piperidinium)s is developed. • The effect of IECs on the performance of s-PDTP- x ionomers and AEMs is elucidated. • s-PDTP- x copolymers display excellent durability >1000 h in 1 M NaOH at 80 °C. • s-PDTP-based AEMFCs reach power densities of 1.04 W cm −2 in H 2 -air.

Preparation and characterization of side-chain poly(aryl ether ketone) anion exchange membranes by superacid-catalyzed reaction

The poly(aryl ether ketone) with spatial cardo structure is prepared from 4,4′-bis(phenoxy)benzophenone and 1-(4-bromobutyl)indoline-2,3-dione through a facile polyhydroxyalkylation reaction catalyzed by superacid. The number average molecular weight of the resultant polymer is achieved as high as 105.6 kg mmol−1. Three anion exchange membranes were prepared by reacting the polymer with trimethylamine, N-methyl-piperidine, and N,N,N′,N′,N″-pentaethylguanidine, respectively. Among the prepared membranes, N-methyl-piperidine based anion exchange membrane exhibited the highest OH− conductivity of 99.8 mS cm−1 at corresponding IEC of 1.54 meq g−1. In addition, the prepared membranes also exhibit excellent mechanical properties, in which the tensile strength and elongation at break can reach up to 50 MPa and 35%, respectively. Moreover, the anion exchange membranes exhibited good alkaline stability. When they were treated with 1 M KOH at 60 °C for 600 h, their conductivity decreased by less than 5%.

Impact of N-Substituent and pKa of Azole Rings on Fuel Cell Performance and Phosphoric Acid Loss.

The influence of N-substituent and pKa of azole rings has been investigated for the performance of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). Imidazole, benzimidazole, and triazole groups were functionalized on the side chains of poly(phenylene oxide), respectively. Each azole group is categorized by their N-substituent into two types: unsubstituted and methyl-substituted azoles. The membranes with methyl-substituted azoles showed higher phosphoric acid (PA) doping levels with an average increase of 20% compared to those with unsubstituted azoles in the full-doped states. However, unsubstituted azoles more effectively improved the proton conductivity and the membrane with unsubstituted imidazole (IMPPO-H) showed a high anhydrous proton conductivity of 153 mS/cm at 150 °C. In contrast, the membranes with methyl-substituted azoles showed a higher PA retention with an average increase of 81% compared to those with unsubstituted azoles. The higher PA retention of methyl-substituted azoles also led to the higher fuel cell performance with the maximum increase of 95% in the power density. It was also revealed that higher pKa of azoles enhanced the PA retention and the fuel cell performance. Based on the experimental results of PA retention and density functional theory calculations, the PA loss mechanism was also proposed.

Breaking or following the membrane-targeting mechanism: Exploring the antibacterial mechanism of host defense peptide mimicking poly(2-oxazoline)s

Peptides exert important biological functions but their application is hindered by their susceptibility to proteolysis and poor stability in vivo. Thus, functional peptide mimics have drawn a great deal of attention to address this challenge. Poly(2-oxazoline)s, a class of biocompatible and proteolysis-resistant polymer, can work as host defense peptide mimics without following the general membrane-targeting mechanism as shown in our previous work. This observation encouraged us to figure out if poly(2-oxazoline)s are special and break the general membrane-targeting mechanism of host defense peptides and their mimics. In this study, we aimed at the connection between structure and antibacterial mechanism of poly(2-oxazoline)s. A new γ-aminobutyric acid (GABA)-pendent poly(2-oxazoline) was synthesized and investigated to compare with glycine-pendent poly(2-oxazoline) in our previous study, with the former polymer has two extra CH2 groups in the sidechain to increase the hydrophobicity and amphiphilicity. Membrane depolarization assay suggested that incorporating two more CH2 groups into the sidechain of poly(2-oxazoline) resulted in a mechanism switch from DNA-targeting to membrane-targeting, which was supported by the slow time-kill kinetics and slightly distorted and sunken membrane morphology. Besides, GABA-pendent poly(2-oxazoline) showed potent activity against methicillin-resistant S. aureus and low hemolysis on human red blood cells. Moreover, repeated use of the antimicrobial poly(2-oxazoline) did not stimulate bacteria to obtain resistance, which was an obvious advantage of membrane-targeting antimicrobial agents.

Palladium Separation by Pd-Catalyzed Gel Formation via Alkyne Coupling

Selective entrapment of precious metals from industrial wastes containing various metals is a most challenging branch of environmental science. Developed methods like solvent or solid-phase extraction, ion exchange, co-precipitation, membrane filtration, and adsorption rely on chelation, electrostatic attraction, or ion exchange, and these methods present limited selectivity and require post-treatment for further application. Herein, an original concept is reported involving the utilization of the superior catalytic properties of Pd selectively for efficient entrapment of Pd from other metals. Specifically, side chains of poly(vinyl alcohol) (PVA) functionalized with alkynyl groups are catalytically dimerized using Pd(II), which forms gels. The Pd(II) ions are coordinatively encapsulated into the gel networks, while the other metal ions are excluded from the networks, thus allowing the separation and immobilization of Pd. The entrapped Pd(II) is also reduced to Pd(0) nanoparticles (PdNPs) forming PdNPs@al...

Preparation of polymer–rare earth complexes based on Schiff-base-containing salicylic aldehyde groups attached to the polymer and their fluorescence emission properties

AbstractIn this study, the salicylaldehyde hydrazone was bonded onto the side chains of poly (styrene-co-butyl acrylate), firstly obtaining a series of novel Schiff base-functionalized polymers. and using the base-containing polymers as macromolecular ligands through further reaction with EuCl3/YbCl3·6H2O, a series of polymer-rare earth complexes based on Eu(III)/Yb(III) ion were successfully prepared. The structures of the schiff base-containing polymers and their corresponding complexes were characterized by means of infrared spectra and UV spectra. The thermal properties of the functionalized polymers and complexes were investigated by TGA, and the fluorescence properties of the complexes were also researched by fluorescence spectrum. The experimental results show that the complexes have fine thermal stability likely because of the bidentate chelate effect of base-containing polymer and the conjugative effect of salicylaldehyde hydrazone group on the side chain of poly (styrene-co-butyl acrylate). More important, the salicylaldehyde hydrazone group on the side chains of poly(styrene-co-butyl acrylate) can efficaciously sensitize the fluorescence emission of the center ion due to effective intramolecular energy transfer. All the Eu(III)/Yb(III) complexes exhibit characteristic photoluminescence peaks in the visible region. The fluorescence excitation spectra of the complexes were obtained by monitoring the emission of Eu3+/Yb3+ ion at 497 nm, and the peak at 433 nm was found to be the optimal excitation peak. The concentration of salicylaldehyde hydrazone group was changed gradually with the variation of the molar ratio between the butyl acrylate and styrene (1:0.5; 1:1; 1:1.5; 1:2; 1:2.5), and the differences in their fluorescent intensity were followed, and the fluorescence intensity was very weak when the molar ratio of the butyl acrylate to styrene is equal to 1:2.5, while the fluorescence intensity reached a maximum value in the molar ratio of 1:1.