times than that along the surface plane of the film. In this paper we review the recentdevelopmen... more times than that along the surface plane of the film. In this paper we review the recentdevelopment of polymerization technique by low potential electrochemical method performed in our lab andseveral electrical devices in which the compact polythiophene films, such as anionic and cationic sieves, andlaminate film junction of undoped polythiophene derivatives were used.
The development of functional materials based on renewable resources is of great significance in ... more The development of functional materials based on renewable resources is of great significance in today’s resource shortage. Here, we present an effective way to synthesize a mussel-inspired adhesiv...
Abstract During the past ten years, the performance of polymeric field-effect transistors has bee... more Abstract During the past ten years, the performance of polymeric field-effect transistors has been largely improved, not only in mobility but also in durability. Among the factors contributed to such improvements, side-chain engineering plays an important role. Various techniques, such as branch point adjustment, hydrogen-bonding introduction and the incorporation of other functional groups in the side-chain were developed, which greatly altered the crystallinity, alignment and morphology of the conjugated polymers hence their charge transport behavior. In this review, the side-chain engineering strategies that have been employed in polymeric field-effect transistors are summarized and discussed in detail, which we hope could provide an insight into further development in this area.
The alkylation positions (N-alkylation & O-alkylation) of a bis-lactam containing acceptor has a ... more The alkylation positions (N-alkylation & O-alkylation) of a bis-lactam containing acceptor has a strong influence on the solar cell performance of the corresponding polymers.
Thiazoloisoindigo and its derivatives were synthesized for the first time from thiazoloisatin, wh... more Thiazoloisoindigo and its derivatives were synthesized for the first time from thiazoloisatin, which was obtained via a novel cyclization strategy.
Fluorination density and regioregularity are known factors that have high impact on the performan... more Fluorination density and regioregularity are known factors that have high impact on the performance of organic solar cells; however, due to the limited available fluorination positions, the influence of backbone fluorination positions (such as ortho, para, and meta) has not been well studied. Here we disclose that the fluorination position on a conjugated polymer backbone may have completely opposite effects on its performance. Specifically, compared to the nonfluorinated control, Devices fabricated with the conjugated polymer based on para-fluorinated dibenzo[c,h][2,6]naphthyridine-5,11-(6H,12H)-dione (DBND) block exhibit improved power conversion efficiencies (PCEs) up to 6.55%, while devices fabricated with the conjugated polymer based on ortho-fluorinated DBND block exhibit much worse PCEs as low as 1.44%, although both polymers have similar HOMO/LUMO levels, bandgaps, and backbone torsion angles. It is found that different fluorination positions result in different dipole moments, intermolecular bind...
Abstract A useful synthetic methodology towards new fluoroalkylsulfonates was developed. Grignard... more Abstract A useful synthetic methodology towards new fluoroalkylsulfonates was developed. Grignard addition to an inexpensive and commercially available fluorine-containing ester, methyl 2,2-difluoro-2-(fluorosulfonyl)acetate ( 1 ) gave the mono-adduct ( 2 ) as the only product in high yield. The scope and limitation of this method were thoroughly investigated and it was found that it works for most Grignard reagents except electron-poor ones. Interestingly, the resulting fluoroalkylsulfonates exhibit substituent-dependent hydration behavior due to the presence of carbonyl group in these compounds. Converting the fluoroalkylsulfonate to the acid form and then neutralizing with tetra- n -butylammonium hydroxide gave the corresponding tetra- n -butylammonium salts, which shows good solubility in common organic solvents, some of which might be suitable for copolymerization with other hydrophobic monomers.
The assembly of a peptide-tetrathiophene-peptide (PTP) conjugate has been investigated in mixed s... more The assembly of a peptide-tetrathiophene-peptide (PTP) conjugate has been investigated in mixed solvents, which has different polarities by changing the solvent proportions. It was found that PTP can form fibers in THF/hexane solutions with 40-80%v of hexane. The fibers were stable and did not change on time. On the other hand, PTP formed ordered structures in a mixed solution with the water content from 40 to 60%v. For the as-prepared solutions, two nanostructures vesicles and parallelogram sheets were obtained. The parallelogram sheets could transform into vesicles on time. The fibers showed supramolecular chirality, however, there was no Cotton effect for vesicles and parallelogram sheets. UV-vis, FL, XRD, FT-IR, and CD spectra together with SEM, AFM, TEM were used to characterize the nanostructures and properties of the assemblies. Molecular packing mechanism was proposed based on the experimental data.
effectively prevent the initial attachment of bacteria to implant and device surfaces and subsequ... more effectively prevent the initial attachment of bacteria to implant and device surfaces and subsequently avoid the device-related infection. [18-21] In order to obtain such antibacterial coatings, several mussel-inspired polymers, including polydopamine, [22,23] catechol-derived poly(ethylene glycol), [24,25] and poly(acrylate-co-acrylamide), [26] were chosen as the coating matrixes. Many ingredients, such as Cu 2+ , [27] silver nanoparticle, [28,29] amphiphilic groups, [30] antibiotic, [31,32] peptide, [33] and natural antibacterial agent [34-36] (i.e., tannin, chitosan, and bronel) have been incorporated into these matrix for antibacterial studies. Although these mentioned coatings are effective in prohibition of bacterial growth on surfaces, sophisticated procedures such as surface-initiated polymerization, layerby-layer deposition, and chemical grafting are generally involved in the fabricating process. [37-40] Thus, to develop more facile and simpler methods for preparing mussel-inspired antibacterial coatings are still challenging and deserve further study. Investigations on the attachment plaques from various mussels reveal that the reaction of catechol and amine group (in lysine residues) via the Michael addition or Schiff base reactions play a critical role in the formation of water-insoluble, 3D marine adhesive proteins (MAP) networks. [5,12,41-45] Inspired by this characteristic, Li et al. developed a water-resistant wood adhesive by simply mixing two commercialized materials, branched polyethyleneimine (PEI), a low-cost and amine groups-enriched industrially material and tannin (TA), a natural product rich in catechol groups. [46] Subsequently, this simple and low-cost technology was also used to fabricate functional coatings. [47-50] For example, Wang et al. fabricated hydrophilic modified polypropylene separators by the co-deposition of catechol and polyamine for Li-ion batteries. [51] Xu et al. reported the co-deposition of catechol and PEI onto nanofiltration membrane for textile wastewater treatment. [52] What's more, based on this technology, the usage of noneconomic catechol-containing materials such as dopamine (including polydopamine) or synthetic catechol-derived polymers was also avoided. Nevertheless, to our best knowledge, this simple and facile method has not been applied in the design of mussel-inspired antibacterial coatings. In this study, we, for the first time, synthesized a musselinspired antibacterial coating via the simple co-deposition of PEI and a quaternized catechol (QCat) in an aqueous Antibacterial Coatings Although significant progress has been made in the preparation of musselinspired antibacterial coatings, continual challenges still remain in pursuing more facile and simpler fabrication methods to construct more robust and effective coatings. In this study, quaternized catechol (QCat), which is synthesized via a simple quaternization reaction from two commercially available materials, 2-chloro-3′,4′-dihydroxyacetophenone and N,N-dimethyldodecylamine, is used as a reactive antimicrobial agent to fabricate musselinspired antibacterial coatings. Specifically, QCat reacts with branched polyethyleneimine (PEI) in Tris-HCl solution through a cross-linking reaction between amino and catechol groups to form a homogeneous coating on various substrates via a simple co-deposition process. The formed PEI/QCat coating exhibits highly effective antimicrobial activity against both Staphylococcus aureus and Escherichia coli and good adhesion on glass, metal, and plastic substrates. Such a simple fabrication process makes it a potential candidate for industrial and medical applications.
A new scolopendra-type polymer of polydodecyloxybenzoyl[1,5]-diazocine (PDBD) was designed and pr... more A new scolopendra-type polymer of polydodecyloxybenzoyl[1,5]-diazocine (PDBD) was designed and prepared using 2,5-bis(4-(dodecyloxy)-benzoyl)terephthaloyl azide with trifluoroacetic acid (TFA) via one-pot reaction in good yields. The structure of polymer was characterized using 1 H-NMR, 13 C-NMR and MALDI-TOF spectra. The polymer PDBD exhibits good thermal stability as measured by TGA and DSC, and can be dissolved well in common organic solvents such as chloroform and tetrahydrofuran. In addition, UV-Vis spectral studies indicate that the polymer PDBD shows unique optical property changes (protonation/deprotonation) in the different trifluoroacetic acid environments. The new polymer is expected to be utilized as an optical functional material for fabricating optical sensors in environmental and biological fields.
Although the role of 3,4-dihydroxyphenyl-L-alanine(DOPA)in mussel foot proteins (mfps) in the rea... more Although the role of 3,4-dihydroxyphenyl-L-alanine(DOPA)in mussel foot proteins (mfps) in the realization of underwater bonding has been widely recognized, the role of the polarity of the polymer was largely overlooked. Here, by systematically comparing the underwater bonding properties of four mussel-inspired adhesives with different amide/lactam contents but similar catechol contents and molecular weights, we came to the conclusion that the polarity of the polymers also contributes to the strong underwater bonding. With the increase in the amide/lactam contents, the polarity of the polymeric adhesive increases, which correlates to the improved underwater bonding strength. A dielectric constant is introduced to evaluate the polarity of the polymer, which may be used as a guidance for the design of mussel-inspired adhesives with even better underwater bonding properties.
Lactam-containing conjugated molecules are important building blocks for conjugated polymers for ... more Lactam-containing conjugated molecules are important building blocks for conjugated polymers for high performance organic field-effect transistors (OFETs). The alkylation on conjugated lactam building blocks may preferably produce either O-alkylated or N-alkylated isomers, which might have different influences on the HOMO/LUMO energy levels, π–π stacking patterns and crystallinity of the corresponding polymers. However, the influence of O-alkylation and N-alkylation on the OFET performance of the resultant polymers has not been reported. Here, with an improved synthetic strategy, we prepared the N-alkylated isomer of dibenzonaphthyridinedione (DBND), a tetracyclic lactam building block that used to give O-alkylated product preferably, which gave us a chance to compare the influence of N-alkylated DBND (N-DBND) and O-alkylated DBND (O-DBND) on the OFET performance of the corresponding polymers. It was found that the polymer based on N-DBND exhibits a much higher hole mobility (0.55 cm2 V–1 s–1), almost 100...
A facile and efficient method to fabricate robust antifouling coatings via a grafting-to approach... more A facile and efficient method to fabricate robust antifouling coatings via a grafting-to approach based on polyvinyl alcohol (PVA)-based biomimetic substrates is reported.
Chemistry (Weinheim an der Bergstrasse, Germany), Jan 24, 2018
Thiazoloisoindigo, a novel structural variation of isoindigo, is for the first time utilized to s... more Thiazoloisoindigo, a novel structural variation of isoindigo, is for the first time utilized to synthesize conjugated polymers. Polymer based on thiazoloisoindigo merges the advantages of the one based on thienoisoindigo and diazaisoindigo: It not only exhibits a greatly red shifted UV-vis absorption to the near-infrared region due to its strong tendency to form quinoidal structures, similar to that based on thienoisoindigo, but also shows excellent ambipolar mobility (hole 3.93 and electron 1.07 cm2 V-1 s-1, respectively) in organic field-effect transistors (OFETs), superior than that based on diazaisoindigo, showing the strong electron-withdrawing capability of thiazoloisoindigo.
Most wide-bandgap (WBG) conjugated polymers with Eg > 2.2 eV exhibit low power conversion effi... more Most wide-bandgap (WBG) conjugated polymers with Eg > 2.2 eV exhibit low power conversion efficiency (PCE) due to their limited absorption window. Here we report the synthesis of a novel tetracyclic fused building block dibenzonaphthyridinedione (DBND) from isoindigo and its application as an acceptor building block for wide-bandgap copolymers with improved PCE. The Stille copolymerization of this building block with 5,5′-bis(trimethylstannyl)-2,2′-bithiophene (2T) and (E)-1,2-bis(5-(trimethylstannyl)thiophen-2-yl)ethane (TVT) results in two WBG polymers PDBND-2T (Eg 2.32 eV) and PDBND-TVT (Eg 2.23 eV), respectively. Both polymers act as excellent donors in high-performance organic solar cells (OSCs). When blended with phenyl-C71-butyric acid methyl ester (PC71BM), PDBND-2T based OSCs exhibit a PCE of 5.75%, which makes it the broadest bandgap OSCs with PCE over 5%. PDBDN-TVT based OSCs featured a high PCE up to 6.32%. Such efficiency is the highest reported to date for a conjugated polymer at such a broa...
Mussel-inspired controlled-release coatings by the combination of the metal-chelation ability of ... more Mussel-inspired controlled-release coatings by the combination of the metal-chelation ability of catechol and the hydrolysis of acetal are reported.
In this paper, a simple and low-cost approach for the preparation of quaternary ammonium salt (QA... more In this paper, a simple and low-cost approach for the preparation of quaternary ammonium salt (QAS)-containing antibacterial polyurethane (APU) films is described. Epichlorohydrin (ECH), an inexpensive and commercially available chemical, is used to prepare the low-cost antimicrobial PECH-QAS. Then PECH-QAS, three-armed PPG, linear PPG, and diisocyanate are introduced for the synthesis of the APU prepolymer without any solvent in one pot for the first time. Water and three-armed PPG act as the cross-linking initiator and cross-linker in the preparation of the APU films. Using water as the initiator makes the preparation process more environment-friendly, and the cross-linked network guarantees the resistance of the film toward solvent corrosion. The influence of molecule weight of PECH-QAS, PECH-QAS concentration, cross-link density, and diisocyanate types on the mechanical properties and antibacterial properties of the APU films is extensively investigated. The optimized APU films exhibit high mechanical performance and excellent antibacterial properties.
times than that along the surface plane of the film. In this paper we review the recentdevelopmen... more times than that along the surface plane of the film. In this paper we review the recentdevelopment of polymerization technique by low potential electrochemical method performed in our lab andseveral electrical devices in which the compact polythiophene films, such as anionic and cationic sieves, andlaminate film junction of undoped polythiophene derivatives were used.
The development of functional materials based on renewable resources is of great significance in ... more The development of functional materials based on renewable resources is of great significance in today’s resource shortage. Here, we present an effective way to synthesize a mussel-inspired adhesiv...
Abstract During the past ten years, the performance of polymeric field-effect transistors has bee... more Abstract During the past ten years, the performance of polymeric field-effect transistors has been largely improved, not only in mobility but also in durability. Among the factors contributed to such improvements, side-chain engineering plays an important role. Various techniques, such as branch point adjustment, hydrogen-bonding introduction and the incorporation of other functional groups in the side-chain were developed, which greatly altered the crystallinity, alignment and morphology of the conjugated polymers hence their charge transport behavior. In this review, the side-chain engineering strategies that have been employed in polymeric field-effect transistors are summarized and discussed in detail, which we hope could provide an insight into further development in this area.
The alkylation positions (N-alkylation & O-alkylation) of a bis-lactam containing acceptor has a ... more The alkylation positions (N-alkylation & O-alkylation) of a bis-lactam containing acceptor has a strong influence on the solar cell performance of the corresponding polymers.
Thiazoloisoindigo and its derivatives were synthesized for the first time from thiazoloisatin, wh... more Thiazoloisoindigo and its derivatives were synthesized for the first time from thiazoloisatin, which was obtained via a novel cyclization strategy.
Fluorination density and regioregularity are known factors that have high impact on the performan... more Fluorination density and regioregularity are known factors that have high impact on the performance of organic solar cells; however, due to the limited available fluorination positions, the influence of backbone fluorination positions (such as ortho, para, and meta) has not been well studied. Here we disclose that the fluorination position on a conjugated polymer backbone may have completely opposite effects on its performance. Specifically, compared to the nonfluorinated control, Devices fabricated with the conjugated polymer based on para-fluorinated dibenzo[c,h][2,6]naphthyridine-5,11-(6H,12H)-dione (DBND) block exhibit improved power conversion efficiencies (PCEs) up to 6.55%, while devices fabricated with the conjugated polymer based on ortho-fluorinated DBND block exhibit much worse PCEs as low as 1.44%, although both polymers have similar HOMO/LUMO levels, bandgaps, and backbone torsion angles. It is found that different fluorination positions result in different dipole moments, intermolecular bind...
Abstract A useful synthetic methodology towards new fluoroalkylsulfonates was developed. Grignard... more Abstract A useful synthetic methodology towards new fluoroalkylsulfonates was developed. Grignard addition to an inexpensive and commercially available fluorine-containing ester, methyl 2,2-difluoro-2-(fluorosulfonyl)acetate ( 1 ) gave the mono-adduct ( 2 ) as the only product in high yield. The scope and limitation of this method were thoroughly investigated and it was found that it works for most Grignard reagents except electron-poor ones. Interestingly, the resulting fluoroalkylsulfonates exhibit substituent-dependent hydration behavior due to the presence of carbonyl group in these compounds. Converting the fluoroalkylsulfonate to the acid form and then neutralizing with tetra- n -butylammonium hydroxide gave the corresponding tetra- n -butylammonium salts, which shows good solubility in common organic solvents, some of which might be suitable for copolymerization with other hydrophobic monomers.
The assembly of a peptide-tetrathiophene-peptide (PTP) conjugate has been investigated in mixed s... more The assembly of a peptide-tetrathiophene-peptide (PTP) conjugate has been investigated in mixed solvents, which has different polarities by changing the solvent proportions. It was found that PTP can form fibers in THF/hexane solutions with 40-80%v of hexane. The fibers were stable and did not change on time. On the other hand, PTP formed ordered structures in a mixed solution with the water content from 40 to 60%v. For the as-prepared solutions, two nanostructures vesicles and parallelogram sheets were obtained. The parallelogram sheets could transform into vesicles on time. The fibers showed supramolecular chirality, however, there was no Cotton effect for vesicles and parallelogram sheets. UV-vis, FL, XRD, FT-IR, and CD spectra together with SEM, AFM, TEM were used to characterize the nanostructures and properties of the assemblies. Molecular packing mechanism was proposed based on the experimental data.
effectively prevent the initial attachment of bacteria to implant and device surfaces and subsequ... more effectively prevent the initial attachment of bacteria to implant and device surfaces and subsequently avoid the device-related infection. [18-21] In order to obtain such antibacterial coatings, several mussel-inspired polymers, including polydopamine, [22,23] catechol-derived poly(ethylene glycol), [24,25] and poly(acrylate-co-acrylamide), [26] were chosen as the coating matrixes. Many ingredients, such as Cu 2+ , [27] silver nanoparticle, [28,29] amphiphilic groups, [30] antibiotic, [31,32] peptide, [33] and natural antibacterial agent [34-36] (i.e., tannin, chitosan, and bronel) have been incorporated into these matrix for antibacterial studies. Although these mentioned coatings are effective in prohibition of bacterial growth on surfaces, sophisticated procedures such as surface-initiated polymerization, layerby-layer deposition, and chemical grafting are generally involved in the fabricating process. [37-40] Thus, to develop more facile and simpler methods for preparing mussel-inspired antibacterial coatings are still challenging and deserve further study. Investigations on the attachment plaques from various mussels reveal that the reaction of catechol and amine group (in lysine residues) via the Michael addition or Schiff base reactions play a critical role in the formation of water-insoluble, 3D marine adhesive proteins (MAP) networks. [5,12,41-45] Inspired by this characteristic, Li et al. developed a water-resistant wood adhesive by simply mixing two commercialized materials, branched polyethyleneimine (PEI), a low-cost and amine groups-enriched industrially material and tannin (TA), a natural product rich in catechol groups. [46] Subsequently, this simple and low-cost technology was also used to fabricate functional coatings. [47-50] For example, Wang et al. fabricated hydrophilic modified polypropylene separators by the co-deposition of catechol and polyamine for Li-ion batteries. [51] Xu et al. reported the co-deposition of catechol and PEI onto nanofiltration membrane for textile wastewater treatment. [52] What's more, based on this technology, the usage of noneconomic catechol-containing materials such as dopamine (including polydopamine) or synthetic catechol-derived polymers was also avoided. Nevertheless, to our best knowledge, this simple and facile method has not been applied in the design of mussel-inspired antibacterial coatings. In this study, we, for the first time, synthesized a musselinspired antibacterial coating via the simple co-deposition of PEI and a quaternized catechol (QCat) in an aqueous Antibacterial Coatings Although significant progress has been made in the preparation of musselinspired antibacterial coatings, continual challenges still remain in pursuing more facile and simpler fabrication methods to construct more robust and effective coatings. In this study, quaternized catechol (QCat), which is synthesized via a simple quaternization reaction from two commercially available materials, 2-chloro-3′,4′-dihydroxyacetophenone and N,N-dimethyldodecylamine, is used as a reactive antimicrobial agent to fabricate musselinspired antibacterial coatings. Specifically, QCat reacts with branched polyethyleneimine (PEI) in Tris-HCl solution through a cross-linking reaction between amino and catechol groups to form a homogeneous coating on various substrates via a simple co-deposition process. The formed PEI/QCat coating exhibits highly effective antimicrobial activity against both Staphylococcus aureus and Escherichia coli and good adhesion on glass, metal, and plastic substrates. Such a simple fabrication process makes it a potential candidate for industrial and medical applications.
A new scolopendra-type polymer of polydodecyloxybenzoyl[1,5]-diazocine (PDBD) was designed and pr... more A new scolopendra-type polymer of polydodecyloxybenzoyl[1,5]-diazocine (PDBD) was designed and prepared using 2,5-bis(4-(dodecyloxy)-benzoyl)terephthaloyl azide with trifluoroacetic acid (TFA) via one-pot reaction in good yields. The structure of polymer was characterized using 1 H-NMR, 13 C-NMR and MALDI-TOF spectra. The polymer PDBD exhibits good thermal stability as measured by TGA and DSC, and can be dissolved well in common organic solvents such as chloroform and tetrahydrofuran. In addition, UV-Vis spectral studies indicate that the polymer PDBD shows unique optical property changes (protonation/deprotonation) in the different trifluoroacetic acid environments. The new polymer is expected to be utilized as an optical functional material for fabricating optical sensors in environmental and biological fields.
Although the role of 3,4-dihydroxyphenyl-L-alanine(DOPA)in mussel foot proteins (mfps) in the rea... more Although the role of 3,4-dihydroxyphenyl-L-alanine(DOPA)in mussel foot proteins (mfps) in the realization of underwater bonding has been widely recognized, the role of the polarity of the polymer was largely overlooked. Here, by systematically comparing the underwater bonding properties of four mussel-inspired adhesives with different amide/lactam contents but similar catechol contents and molecular weights, we came to the conclusion that the polarity of the polymers also contributes to the strong underwater bonding. With the increase in the amide/lactam contents, the polarity of the polymeric adhesive increases, which correlates to the improved underwater bonding strength. A dielectric constant is introduced to evaluate the polarity of the polymer, which may be used as a guidance for the design of mussel-inspired adhesives with even better underwater bonding properties.
Lactam-containing conjugated molecules are important building blocks for conjugated polymers for ... more Lactam-containing conjugated molecules are important building blocks for conjugated polymers for high performance organic field-effect transistors (OFETs). The alkylation on conjugated lactam building blocks may preferably produce either O-alkylated or N-alkylated isomers, which might have different influences on the HOMO/LUMO energy levels, π–π stacking patterns and crystallinity of the corresponding polymers. However, the influence of O-alkylation and N-alkylation on the OFET performance of the resultant polymers has not been reported. Here, with an improved synthetic strategy, we prepared the N-alkylated isomer of dibenzonaphthyridinedione (DBND), a tetracyclic lactam building block that used to give O-alkylated product preferably, which gave us a chance to compare the influence of N-alkylated DBND (N-DBND) and O-alkylated DBND (O-DBND) on the OFET performance of the corresponding polymers. It was found that the polymer based on N-DBND exhibits a much higher hole mobility (0.55 cm2 V–1 s–1), almost 100...
A facile and efficient method to fabricate robust antifouling coatings via a grafting-to approach... more A facile and efficient method to fabricate robust antifouling coatings via a grafting-to approach based on polyvinyl alcohol (PVA)-based biomimetic substrates is reported.
Chemistry (Weinheim an der Bergstrasse, Germany), Jan 24, 2018
Thiazoloisoindigo, a novel structural variation of isoindigo, is for the first time utilized to s... more Thiazoloisoindigo, a novel structural variation of isoindigo, is for the first time utilized to synthesize conjugated polymers. Polymer based on thiazoloisoindigo merges the advantages of the one based on thienoisoindigo and diazaisoindigo: It not only exhibits a greatly red shifted UV-vis absorption to the near-infrared region due to its strong tendency to form quinoidal structures, similar to that based on thienoisoindigo, but also shows excellent ambipolar mobility (hole 3.93 and electron 1.07 cm2 V-1 s-1, respectively) in organic field-effect transistors (OFETs), superior than that based on diazaisoindigo, showing the strong electron-withdrawing capability of thiazoloisoindigo.
Most wide-bandgap (WBG) conjugated polymers with Eg > 2.2 eV exhibit low power conversion effi... more Most wide-bandgap (WBG) conjugated polymers with Eg > 2.2 eV exhibit low power conversion efficiency (PCE) due to their limited absorption window. Here we report the synthesis of a novel tetracyclic fused building block dibenzonaphthyridinedione (DBND) from isoindigo and its application as an acceptor building block for wide-bandgap copolymers with improved PCE. The Stille copolymerization of this building block with 5,5′-bis(trimethylstannyl)-2,2′-bithiophene (2T) and (E)-1,2-bis(5-(trimethylstannyl)thiophen-2-yl)ethane (TVT) results in two WBG polymers PDBND-2T (Eg 2.32 eV) and PDBND-TVT (Eg 2.23 eV), respectively. Both polymers act as excellent donors in high-performance organic solar cells (OSCs). When blended with phenyl-C71-butyric acid methyl ester (PC71BM), PDBND-2T based OSCs exhibit a PCE of 5.75%, which makes it the broadest bandgap OSCs with PCE over 5%. PDBDN-TVT based OSCs featured a high PCE up to 6.32%. Such efficiency is the highest reported to date for a conjugated polymer at such a broa...
Mussel-inspired controlled-release coatings by the combination of the metal-chelation ability of ... more Mussel-inspired controlled-release coatings by the combination of the metal-chelation ability of catechol and the hydrolysis of acetal are reported.
In this paper, a simple and low-cost approach for the preparation of quaternary ammonium salt (QA... more In this paper, a simple and low-cost approach for the preparation of quaternary ammonium salt (QAS)-containing antibacterial polyurethane (APU) films is described. Epichlorohydrin (ECH), an inexpensive and commercially available chemical, is used to prepare the low-cost antimicrobial PECH-QAS. Then PECH-QAS, three-armed PPG, linear PPG, and diisocyanate are introduced for the synthesis of the APU prepolymer without any solvent in one pot for the first time. Water and three-armed PPG act as the cross-linking initiator and cross-linker in the preparation of the APU films. Using water as the initiator makes the preparation process more environment-friendly, and the cross-linked network guarantees the resistance of the film toward solvent corrosion. The influence of molecule weight of PECH-QAS, PECH-QAS concentration, cross-link density, and diisocyanate types on the mechanical properties and antibacterial properties of the APU films is extensively investigated. The optimized APU films exhibit high mechanical performance and excellent antibacterial properties.
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