Dear Editor,Timely and effective hemostasis is of great significance for reducing body damage and mortality of patients [1]. Alginate is generally considered to be an excellent hemostatic polymer-based biomaterial and...Dear Editor,Timely and effective hemostasis is of great significance for reducing body damage and mortality of patients [1]. Alginate is generally considered to be an excellent hemostatic polymer-based biomaterial and has been approved by the Food and Drug Administration as Generally Recognized as Safe [2]. However, the violent crosslinking reaction and unstable structure at the wound site limit its clinical applications. Hence, we report a biocompatible and injectable composite hydrogel methacrylate alginate (Alg-AEMA)-based Eosin Y/N-phenylglycine (NPG)-initiated composite hydrogel (AEC) composed of photocrosslinkable alginate, viscosity modifiers and novel white light photoinitiator, namely Eosin Y/NPG system, for instant hemorrhage control.展开更多
The host structure of polymers significantly influences ion transport and interfacial stability of electrolytes,dictating battery cycle life and safety for solid-state lithium metal batteries.Despite promising propert...The host structure of polymers significantly influences ion transport and interfacial stability of electrolytes,dictating battery cycle life and safety for solid-state lithium metal batteries.Despite promising properties of ethylene oxide-based electrolytes,their typical clamp-like coordination geometry leads to crowd solvation sheath and overly strong interactions between Li^(+)and electrolytes,rendering difficult dissociation of Li+and unfavorable solid electrolyte interface(SEI).Herein,we explore weakly solvating characteristics of polyacetal electrolytes owing to their alternately changing intervals between–O–coordinating sites in the main chain.Such structural asymmetry leads to unique distorted helical solvation sheath,and can effectively reduce Li^(+)-electrolyte binding and tune Li^(+)desolvation kinetics in the insitu formed polymer electrolytes,yielding anion-derived SEI and dendrite-free Li electrodeposition.Combining with photoinitiated cationic ring-opening polymerization,polyacetal electrolytes can be instantly formed within 5 min at the surface of electrode,with high segmental chain motion and well adapted interfaces.Such in-situ polyacetal electrolytes enabled more than 1300-h of stable lithium electrodeposition and prolonged cyclability over 200 cycles in solid-state batteries at ambient temperatures,demonstrating the vital role of molecular structure in changing solvating behavior and Li deposition stability for high-performance electrolytes.展开更多
Dodecyl-benzophenone(DBP) and hexadecoxyl-benzophenone(HDBP) as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTI...Dodecyl-benzophenone(DBP) and hexadecoxyl-benzophenone(HDBP) as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTIR spectroscopy. The UV-Vis absorption spectra of DBP and HDBP, propitious to photopolymerization under a commercial mercury UV bulb are centered at 345 and 335 nm, respectively. HDBP has higher extinction coefficient than DBP, but lower photoinitiating efficiency. Their photoinitiating performances for EB605, a bisphenol A epoxy acrylate with 40%(mass fraction) tripropyleneglycol diacrylate (TPGDA), resin consisting of bisphenol A epoxy acrylate and tripropyleneglycol diacrylate in the presence of triethanolamine as a coinitiator were investigated by photo-differential scanning calorimetry(photo-DSC). DBP initiates the curing of acrylate more efficiently than HDBP, showing higher photopolymerization rate and unsaturation conversion, resulted from the poor compatibility of HDBP with the resin. The photoinitiating activity of DBP to epoxy acrylate resin is even higher than that of BP at lower loadings.展开更多
Alkyl-substituted ferrocenium salts have limited solubility in epoxy oligomers and produce poisonous arene by photolysis. Herein, the synthesis and photoactivity of several alkoxy-substituted ferrocenium salts as long...Alkyl-substituted ferrocenium salts have limited solubility in epoxy oligomers and produce poisonous arene by photolysis. Herein, the synthesis and photoactivity of several alkoxy-substituted ferrocenium salts as long-wavelength UV light photoinitiators have been reported. [Cyclopendadien-Fe-anisole]PF6, [Cyclopendadien-Fe-anisole]BF4, [Cyclopendadien-Fe-diphenylether]PF6, [Cyclopendadien-Fe-diphenylether]BF4. and [Cyclopendadien-Fe-diethoxybenzene] PF6 for polymerization of epoxy resin were prepared through the ligand exchange reaction between one ring of ferrocene and aromatic ether. They all display good solubility and photoinitiating activities in epoxy resins.展开更多
Photopolymerization of propargyl acetate (PAT) with Michler's ketone (MK) asphotoinitiator in benzene has been investigated for the first time. Some features of the PATphotopolymerization with MK as photoinitiator...Photopolymerization of propargyl acetate (PAT) with Michler's ketone (MK) asphotoinitiator in benzene has been investigated for the first time. Some features of the PATphotopolymerization with MK as photoinitiator is described.展开更多
Alkyl-substituted ferrocenium salts have limited solubility in epoxy oligomers and produce poisonous arene by photolysis. Herein, the synthesis and photoactivity of several alkoxy-substituted ferrocenium salts as long...Alkyl-substituted ferrocenium salts have limited solubility in epoxy oligomers and produce poisonous arene by photolysis. Herein, the synthesis and photoactivity of several alkoxy-substituted ferrocenium salts as long-wavelength UV light photoinitiators have been reported. [Cyclopendadien-Fe-anisole]PF6, [Cyclopen- dadien-Fe-anisole]BF4, [Cyclopendadien-Fe-diphenylether]PF6, [Cyclopendadien-Fe-diphenylether]BF4, and [Cyclopendadien-Fe-diethoxybenzene] PF6 for polymerization of epoxy resin were prepared through the ligand exchange reaction between one ring of ferrocene and aromatic ether. They all display good solubility and photoini- tiating activities in epoxy resins.展开更多
Holographic parameters and photobleaching kinetics of the photopolymers with five different amine photoinitiators are studied. The maximum values of diffraction efficiency, photobleaching coefficient and quantum yield...Holographic parameters and photobleaching kinetics of the photopolymers with five different amine photoinitiators are studied. The maximum values of diffraction efficiency, photobleaching coefficient and quantum yield follow the sequence: Triethanolamine (TEA)〉 Diethanolamine (DEA)〉 Ethanolamine (EA)〉 Triethylamine (TETN)〉 Diethylamine (DETN). The holographic capabilities of photopolymer performances are determined by the number of functional groups in the amine molecular structure. There is an optimum proportion of the photoinitiator, the photosensitizer and the monomer in the test of holographic parameters with different amine concentrations. The maximum diffraction efficiency is 59.26/%, sensitivity is 1.72/times 10^{ - 3}~cm^{2}/mJ, and the maximum refractive modulation index is 4.64/times 10^{ - 4}.展开更多
Photopolymerization process of glycerin triglycidyl ether based systems was studied by an FT-IR spectrometer.An increase in the rate of polymerization for glycerin triglycidyl ether was evident when 3,4-epoxycyclohexy...Photopolymerization process of glycerin triglycidyl ether based systems was studied by an FT-IR spectrometer.An increase in the rate of polymerization for glycerin triglycidyl ether was evident when 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate was added to it.Its copolymerization mechanism was confirmed by using DSC analysis.The effect of ethoxylated trimethyol propane triacrylate on the rate of polymerization for glycerin triglycidyl ether was also studied,and the formation of interpenetrating network tightly cross-link was proposed.展开更多
A series of novel hybrid photoinitiators(YPhCOPhXPhI^+PhPF_6^-,Y = 4-NO_2,4-MeO or 3-Cl,X = O,OCH_2,or nothing),which contain multiple aromatic rings(PhCOPhXPh),were prepared by reaction of easily available aryl keton...A series of novel hybrid photoinitiators(YPhCOPhXPhI^+PhPF_6^-,Y = 4-NO_2,4-MeO or 3-Cl,X = O,OCH_2,or nothing),which contain multiple aromatic rings(PhCOPhXPh),were prepared by reaction of easily available aryl ketones (YPhCOPhXPh) with iodosobenzene diacetate[PhI^+OCOCH_3(CH_3CO_2)^-].The inset of an aromatic ring into p-benzoyldiphenyliodonium hexafluorophophate(PhCOPhI^+PhPF_6^-)(BDPIH,He-type photoinitiator) between diphenyliodonium and benzoyl is propitious both to the preparation and the photoinitiat...展开更多
Iron-arene complex was first introduced by researchers in Ciba-Geigy as an effective photoinitiator for the photocuring of epoxy resin. The photolysis of these complexes has been studied by some authors. The electroch...Iron-arene complex was first introduced by researchers in Ciba-Geigy as an effective photoinitiator for the photocuring of epoxy resin. The photolysis of these complexes has been studied by some authors. The electrochemical study reported in this note provides further evidence for the photolysis process which is crucial for the understanding of the photoinitiation mechanism.展开更多
Time resolved laser spectroscopy and GC/MS were used to investigate the primary processes and the side reactions occurring in benzophenone and chlorothioxanthone/amine systems used as photoinitiators of radical polyme...Time resolved laser spectroscopy and GC/MS were used to investigate the primary processes and the side reactions occurring in benzophenone and chlorothioxanthone/amine systems used as photoinitiators of radical polymerization. The discrepancy observed between the experimental data and the expected behaviour is accounted for by detrimental chemical reaction involving the ketone triplet state, the ketyl radical and the amine-derived radical.展开更多
Ferrocenium monocations as photoinitiators for cationic photopolymerization suffer from a limitation of low absorption and low reactivity under high-pressure Hg lamp. Here, a ferrocenium dication salt, biphenyl bis [...Ferrocenium monocations as photoinitiators for cationic photopolymerization suffer from a limitation of low absorption and low reactivity under high-pressure Hg lamp. Here, a ferrocenium dication salt, biphenyl bis [π-cyclopentadienyl)iron] hexafluorophosphate ([bis(Cp-Fe)-biphenyl] (PF6)2 was synthesized by the ligand exchange reaction between ferrocene and biphenyl. The chemical structure was characterized with FTIR and ^1HNMR. The separation of ferrocenium monocation cyclopentadien-iron-biphenyl hexafluorophosphate ([Cp-Fe-biphenyl] PF6) and dication [bis(Cp-Fe)-biphenyl] (PF6)2 was carried out by column chromatography. The photoactivity of initiating photopolyinerization of epoxide ER14221 was studied as a cationic photoinitiator. [Bis(Cp-Fe)-biphenyl] (PF6)2 can efficiently absorb radiation above 300nm and its photoactivity is higher than that of its monocation.展开更多
The homopolymerization of 5-methyl-5-hexen-2,4-dione (methacryloylacetone, MAA), a vinyl monomer having beta-diketone group, was carried out in the presence of benzophenone (BP)/N, N-dimenthyl-4-toluidine (DMT) system...The homopolymerization of 5-methyl-5-hexen-2,4-dione (methacryloylacetone, MAA), a vinyl monomer having beta-diketone group, was carried out in the presence of benzophenone (BP)/N, N-dimenthyl-4-toluidine (DMT) system. Graft polymerization of acrylamide initiated by eerie ion onto the homopolymer film was investigated and the mechanism of the grafting reaction was proposed on the basis of ESR study. The grafted copolymer was characterized by means of grafting percentage, water absorption, XPS spectra and scanning electron photomicrographs.展开更多
Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO...Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.展开更多
A new microcrystal muscovite composite superabsorbent was synthesized by UV photopolymerization using 2-hydroxy-2-methylpropiophenone(1 173) as photoinitiator,N,N-methylene bisacrylamide(MBA) as crosslinker,acryli...A new microcrystal muscovite composite superabsorbent was synthesized by UV photopolymerization using 2-hydroxy-2-methylpropiophenone(1 173) as photoinitiator,N,N-methylene bisacrylamide(MBA) as crosslinker,acrylic acid(AA),acrylamide(AM) and sodium 4-styrenesulfonate(SSS) as comonomers.Factors affecting water and salt absorption of the microcrystal muscovite composite superabsorbent,such as crosslinker amount,microcrystal muscovite concentration,photoinitiator content,and SSS concentration,were systematically studied.Water retention capacity of the composite superabsorbent was also investigated.The results show that microcrystal muscovite composite superabsorbent has water absorbency of 550 g/g,salt absorbency of 62 g/g,and water retention of 60% after heating at 70 ℃ for 40 h.The microcrystal muscovite is physically combined into the polymeric network without destroying its polycrystalline structure and the surface of the microcrystal muscovite composite superabsorbent has some deep and small holes.展开更多
Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The gra...Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The grafted fibers were characterized by measure-ments of dye uptaking,moisture regain,pull-out forcesof monofilament from cured matrix,as well as by analy-sis of ESCA and ATR-FTIR spectra.All these resultsconfirm that the surface behavior of the UV-irradiationgrafted fibers was greatly improved.It was also provedthat the original excellent mechanical properties of the fi-bers were well-retained after the surface grafting treat-ment.展开更多
Unimolecular Type Ⅱ radical photoinitiators(PIs) have received significant attention in photocuring owing to the fact that they improve the sustainability of the overall process compared with traditional Type Ⅱ radi...Unimolecular Type Ⅱ radical photoinitiators(PIs) have received significant attention in photocuring owing to the fact that they improve the sustainability of the overall process compared with traditional Type Ⅱ radical photoinitiators. However, the photopolymerization efficiency of unimolecular Type Ⅱ radical photoinitiators is hindered by their short excitation wavelengths,poor photon capture abilities, and inefficient photobleaching performance. Herein, we report a coumarin-based self-sufficient initiator(C-NA), which is designed by integrating “hydrogen donor” and “hydrogen acceptor” into the coumarin framework and used for single-component visible light curing. C-NA exhibits a visible light absorbance and high molar extinction coefficient and is completely photobleached under the irradiation of 405 nm light-emitting diodes(LEDs). The formation of free radicals arises from the transfer of hydrogen from the diethylamino group to the coumarin framework, together with a highly efficient photodegradation process of C-NA. Finally, C-NA was successfully applied to prepare a transparent film material. Therefore,C-NA offers new insights into the design of promising unimolecular Type Ⅱ radical photoinitiators for photocuring.展开更多
Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized ...Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized by installing NHPIEs along the TX backbone and characterized.The investigated TX-NHPIEs have a 60 nm redshift and demonstrate sterling initiating efficiency for free radical photopolymerization(FRP)under LED@450 nm light irradiation compared with the commercialized isopropylthioxanthone(ITX).Real-time1Hnuclear magnetic resonance(1H NMR),electron spin resonance(ESR),decarboxylation and gas chromatograph-mass spectrometer(GC–MS)experiments and density functional theory(DFT)reveal that TX-NHPIEs can generate one alkyl radical and one N-centered iminyl radical,which can initiate FRP directly and indirectly,respectively.In other words,TX-NHPIEs absorb one photon and can generate two active radicals,which break through the limitations of common PIs.TX-NHPIE-Cpe demonstrates the highest initiating efficiency,and its application in coatings and 3D printing was also studied,indicating TX-NHPIEs have broad potential applications in photopolymerization processes.展开更多
Photoinitiators(PIs)are widely used in industrial polymerization processes.It has been reported that PIs are ubiquitous in indoor environments and that humans are exposed to PIs,but the occurrence of PIs in natural en...Photoinitiators(PIs)are widely used in industrial polymerization processes.It has been reported that PIs are ubiquitous in indoor environments and that humans are exposed to PIs,but the occurrence of PIs in natural environments are rarely known.In the present study,25 PIs,including 9 benzophenones(BZPs),8 amine co-initiators(ACIs),4 thioxanthones(TXs)and 4 phosphine oxides(POs),were analyzed in water and sediment samples collected from eight riverine outlets of the Pearl River Delta(PRD).Eighteen,14,and 14 of the 25 target PIs were detected in water,suspended particulatematter(SPM)and sediment samples,respectively.The total concentrations of PIs in water,SPM,and sediment were in the ranges of 2.88–96.1 ng/L,9.25–923 ng/g dry weight(dw),and 3.79–56.9 ng/g dw,with geometric mean concentration(GM)of 10.8 ng/L,48.6 ng/g dw,and 17.1 ng/g dw,respectively.A significant linear regression was observed between the log partitioning coefficients(Kd)values of PIs and their log octanol water partition coefficient(Kow)values(R^(2)=0.535,p<0.05).The annual riverine input of PIs to the coastal waters of the South China Sea via eightmain outlets of the PRD was estimated to be 4.12×10^(3)kg/year,and the∑BZPs,∑ACIs,∑TXs and∑POs contributed to 1.96×10^(3),1.24×10^(3),89.6 and 830 kg/year,respectively.This is the first report of a systematic description of the occurrence characteristics of PIs exposure in water,SPM,and sediment.The environmental fate and risks of PIs in aquatic environments need further investigations.展开更多
基金National Key Research and Development Program(2022YFA1104604,2017YFC1103303)Science Fund for National Defense Distinguished Young Scholars(2022-JCJQ-ZQ-016)+2 种基金National Nature Science Foundation of China(32000969,82002056,92268206)Military Medical Research Projects(145AKJ260015000X,2022-JCJQ-ZD-096-00)Key Support Program for Growth Factor Research(SZYZ-TR-03).
文摘Dear Editor,Timely and effective hemostasis is of great significance for reducing body damage and mortality of patients [1]. Alginate is generally considered to be an excellent hemostatic polymer-based biomaterial and has been approved by the Food and Drug Administration as Generally Recognized as Safe [2]. However, the violent crosslinking reaction and unstable structure at the wound site limit its clinical applications. Hence, we report a biocompatible and injectable composite hydrogel methacrylate alginate (Alg-AEMA)-based Eosin Y/N-phenylglycine (NPG)-initiated composite hydrogel (AEC) composed of photocrosslinkable alginate, viscosity modifiers and novel white light photoinitiator, namely Eosin Y/NPG system, for instant hemorrhage control.
基金financially supported by National Natural Science Foundation of China(52003231,22065037)Yunnan Fundamental Research Projects(202201AW070015)。
文摘The host structure of polymers significantly influences ion transport and interfacial stability of electrolytes,dictating battery cycle life and safety for solid-state lithium metal batteries.Despite promising properties of ethylene oxide-based electrolytes,their typical clamp-like coordination geometry leads to crowd solvation sheath and overly strong interactions between Li^(+)and electrolytes,rendering difficult dissociation of Li+and unfavorable solid electrolyte interface(SEI).Herein,we explore weakly solvating characteristics of polyacetal electrolytes owing to their alternately changing intervals between–O–coordinating sites in the main chain.Such structural asymmetry leads to unique distorted helical solvation sheath,and can effectively reduce Li^(+)-electrolyte binding and tune Li^(+)desolvation kinetics in the insitu formed polymer electrolytes,yielding anion-derived SEI and dendrite-free Li electrodeposition.Combining with photoinitiated cationic ring-opening polymerization,polyacetal electrolytes can be instantly formed within 5 min at the surface of electrode,with high segmental chain motion and well adapted interfaces.Such in-situ polyacetal electrolytes enabled more than 1300-h of stable lithium electrodeposition and prolonged cyclability over 200 cycles in solid-state batteries at ambient temperatures,demonstrating the vital role of molecular structure in changing solvating behavior and Li deposition stability for high-performance electrolytes.
基金Supported by the National Natural Science Foundation of China(No50973100)
文摘Dodecyl-benzophenone(DBP) and hexadecoxyl-benzophenone(HDBP) as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTIR spectroscopy. The UV-Vis absorption spectra of DBP and HDBP, propitious to photopolymerization under a commercial mercury UV bulb are centered at 345 and 335 nm, respectively. HDBP has higher extinction coefficient than DBP, but lower photoinitiating efficiency. Their photoinitiating performances for EB605, a bisphenol A epoxy acrylate with 40%(mass fraction) tripropyleneglycol diacrylate (TPGDA), resin consisting of bisphenol A epoxy acrylate and tripropyleneglycol diacrylate in the presence of triethanolamine as a coinitiator were investigated by photo-differential scanning calorimetry(photo-DSC). DBP initiates the curing of acrylate more efficiently than HDBP, showing higher photopolymerization rate and unsaturation conversion, resulted from the poor compatibility of HDBP with the resin. The photoinitiating activity of DBP to epoxy acrylate resin is even higher than that of BP at lower loadings.
基金Supported by the National Natural Science Foundation of China (No.20676012).
文摘Alkyl-substituted ferrocenium salts have limited solubility in epoxy oligomers and produce poisonous arene by photolysis. Herein, the synthesis and photoactivity of several alkoxy-substituted ferrocenium salts as long-wavelength UV light photoinitiators have been reported. [Cyclopendadien-Fe-anisole]PF6, [Cyclopendadien-Fe-anisole]BF4, [Cyclopendadien-Fe-diphenylether]PF6, [Cyclopendadien-Fe-diphenylether]BF4. and [Cyclopendadien-Fe-diethoxybenzene] PF6 for polymerization of epoxy resin were prepared through the ligand exchange reaction between one ring of ferrocene and aromatic ether. They all display good solubility and photoinitiating activities in epoxy resins.
文摘Photopolymerization of propargyl acetate (PAT) with Michler's ketone (MK) asphotoinitiator in benzene has been investigated for the first time. Some features of the PATphotopolymerization with MK as photoinitiator is described.
基金the National Natural Science Foundation of China (No.20676012).
文摘Alkyl-substituted ferrocenium salts have limited solubility in epoxy oligomers and produce poisonous arene by photolysis. Herein, the synthesis and photoactivity of several alkoxy-substituted ferrocenium salts as long-wavelength UV light photoinitiators have been reported. [Cyclopendadien-Fe-anisole]PF6, [Cyclopen- dadien-Fe-anisole]BF4, [Cyclopendadien-Fe-diphenylether]PF6, [Cyclopendadien-Fe-diphenylether]BF4, and [Cyclopendadien-Fe-diethoxybenzene] PF6 for polymerization of epoxy resin were prepared through the ligand exchange reaction between one ring of ferrocene and aromatic ether. They all display good solubility and photoini- tiating activities in epoxy resins.
基金supported by the Natural Science Foundation of Henan University, China (Grant No. 06ZDZR002)
文摘Holographic parameters and photobleaching kinetics of the photopolymers with five different amine photoinitiators are studied. The maximum values of diffraction efficiency, photobleaching coefficient and quantum yield follow the sequence: Triethanolamine (TEA)〉 Diethanolamine (DEA)〉 Ethanolamine (EA)〉 Triethylamine (TETN)〉 Diethylamine (DETN). The holographic capabilities of photopolymer performances are determined by the number of functional groups in the amine molecular structure. There is an optimum proportion of the photoinitiator, the photosensitizer and the monomer in the test of holographic parameters with different amine concentrations. The maximum diffraction efficiency is 59.26/%, sensitivity is 1.72/times 10^{ - 3}~cm^{2}/mJ, and the maximum refractive modulation index is 4.64/times 10^{ - 4}.
基金Funded by the Innovatory Group Program of the Natural Science Foundation of Hubei Province (2004ABC001)the National "863" Hi-tech Foundation of China (2002AA6Z3083)
文摘Photopolymerization process of glycerin triglycidyl ether based systems was studied by an FT-IR spectrometer.An increase in the rate of polymerization for glycerin triglycidyl ether was evident when 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate was added to it.Its copolymerization mechanism was confirmed by using DSC analysis.The effect of ethoxylated trimethyol propane triacrylate on the rate of polymerization for glycerin triglycidyl ether was also studied,and the formation of interpenetrating network tightly cross-link was proposed.
基金supported by the National Natural Science Foundation of China(No.20772102)Doctor Student Research Foundation of Chinese Education Ministry(No.20060530002)
文摘A series of novel hybrid photoinitiators(YPhCOPhXPhI^+PhPF_6^-,Y = 4-NO_2,4-MeO or 3-Cl,X = O,OCH_2,or nothing),which contain multiple aromatic rings(PhCOPhXPh),were prepared by reaction of easily available aryl ketones (YPhCOPhXPh) with iodosobenzene diacetate[PhI^+OCOCH_3(CH_3CO_2)^-].The inset of an aromatic ring into p-benzoyldiphenyliodonium hexafluorophophate(PhCOPhI^+PhPF_6^-)(BDPIH,He-type photoinitiator) between diphenyliodonium and benzoyl is propitious both to the preparation and the photoinitiat...
基金Supported by the National Natural Science Foundation of China
文摘Iron-arene complex was first introduced by researchers in Ciba-Geigy as an effective photoinitiator for the photocuring of epoxy resin. The photolysis of these complexes has been studied by some authors. The electrochemical study reported in this note provides further evidence for the photolysis process which is crucial for the understanding of the photoinitiation mechanism.
文摘Time resolved laser spectroscopy and GC/MS were used to investigate the primary processes and the side reactions occurring in benzophenone and chlorothioxanthone/amine systems used as photoinitiators of radical polymerization. The discrepancy observed between the experimental data and the expected behaviour is accounted for by detrimental chemical reaction involving the ketone triplet state, the ketyl radical and the amine-derived radical.
基金Supported by the National Natural Science Foundation of China (20676012).
文摘Ferrocenium monocations as photoinitiators for cationic photopolymerization suffer from a limitation of low absorption and low reactivity under high-pressure Hg lamp. Here, a ferrocenium dication salt, biphenyl bis [π-cyclopentadienyl)iron] hexafluorophosphate ([bis(Cp-Fe)-biphenyl] (PF6)2 was synthesized by the ligand exchange reaction between ferrocene and biphenyl. The chemical structure was characterized with FTIR and ^1HNMR. The separation of ferrocenium monocation cyclopentadien-iron-biphenyl hexafluorophosphate ([Cp-Fe-biphenyl] PF6) and dication [bis(Cp-Fe)-biphenyl] (PF6)2 was carried out by column chromatography. The photoactivity of initiating photopolyinerization of epoxide ER14221 was studied as a cationic photoinitiator. [Bis(Cp-Fe)-biphenyl] (PF6)2 can efficiently absorb radiation above 300nm and its photoactivity is higher than that of its monocation.
基金The project was supported by the National Natural Science Foundation of Chna.
文摘The homopolymerization of 5-methyl-5-hexen-2,4-dione (methacryloylacetone, MAA), a vinyl monomer having beta-diketone group, was carried out in the presence of benzophenone (BP)/N, N-dimenthyl-4-toluidine (DMT) system. Graft polymerization of acrylamide initiated by eerie ion onto the homopolymer film was investigated and the mechanism of the grafting reaction was proposed on the basis of ESR study. The grafted copolymer was characterized by means of grafting percentage, water absorption, XPS spectra and scanning electron photomicrographs.
文摘Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.
基金Funded by Sichuan Provincial Science&Technology Pillar Program,China(Nos.2010GZ0128,2014GZX0010)Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,China(No.SKLGP2012K004)the Sichuan Youth Science and Technology Innovation Research Team Funding Scheme,China(No.2013TD0005)
文摘A new microcrystal muscovite composite superabsorbent was synthesized by UV photopolymerization using 2-hydroxy-2-methylpropiophenone(1 173) as photoinitiator,N,N-methylene bisacrylamide(MBA) as crosslinker,acrylic acid(AA),acrylamide(AM) and sodium 4-styrenesulfonate(SSS) as comonomers.Factors affecting water and salt absorption of the microcrystal muscovite composite superabsorbent,such as crosslinker amount,microcrystal muscovite concentration,photoinitiator content,and SSS concentration,were systematically studied.Water retention capacity of the composite superabsorbent was also investigated.The results show that microcrystal muscovite composite superabsorbent has water absorbency of 550 g/g,salt absorbency of 62 g/g,and water retention of 60% after heating at 70 ℃ for 40 h.The microcrystal muscovite is physically combined into the polymeric network without destroying its polycrystalline structure and the surface of the microcrystal muscovite composite superabsorbent has some deep and small holes.
文摘Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The grafted fibers were characterized by measure-ments of dye uptaking,moisture regain,pull-out forcesof monofilament from cured matrix,as well as by analy-sis of ESCA and ATR-FTIR spectra.All these resultsconfirm that the surface behavior of the UV-irradiationgrafted fibers was greatly improved.It was also provedthat the original excellent mechanical properties of the fi-bers were well-retained after the surface grafting treat-ment.
基金supported by the National Natural Science Foundation of China (21925802, 22338005)the Liaoning Binhai Laboratory (LBLB-2023-03)the Fundamental Research Funds for the Central Universities (DUT22LAB601)。
文摘Unimolecular Type Ⅱ radical photoinitiators(PIs) have received significant attention in photocuring owing to the fact that they improve the sustainability of the overall process compared with traditional Type Ⅱ radical photoinitiators. However, the photopolymerization efficiency of unimolecular Type Ⅱ radical photoinitiators is hindered by their short excitation wavelengths,poor photon capture abilities, and inefficient photobleaching performance. Herein, we report a coumarin-based self-sufficient initiator(C-NA), which is designed by integrating “hydrogen donor” and “hydrogen acceptor” into the coumarin framework and used for single-component visible light curing. C-NA exhibits a visible light absorbance and high molar extinction coefficient and is completely photobleached under the irradiation of 405 nm light-emitting diodes(LEDs). The formation of free radicals arises from the transfer of hydrogen from the diethylamino group to the coumarin framework, together with a highly efficient photodegradation process of C-NA. Finally, C-NA was successfully applied to prepare a transparent film material. Therefore,C-NA offers new insights into the design of promising unimolecular Type Ⅱ radical photoinitiators for photocuring.
基金the financial support by the National Natural Science Foundation of China(Nos.22301107,52373057)the Nature Science Foundation of Jiangsu Province(No.BK20200610)+1 种基金the Fundamental Research Funds for the Central Universities(No.JUSRP122021)Jiangsu Province"Innovation and Entrepreneurship Doctor"Talent Plan(No.JSSCBS20221053)also provided support。
文摘Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized by installing NHPIEs along the TX backbone and characterized.The investigated TX-NHPIEs have a 60 nm redshift and demonstrate sterling initiating efficiency for free radical photopolymerization(FRP)under LED@450 nm light irradiation compared with the commercialized isopropylthioxanthone(ITX).Real-time1Hnuclear magnetic resonance(1H NMR),electron spin resonance(ESR),decarboxylation and gas chromatograph-mass spectrometer(GC–MS)experiments and density functional theory(DFT)reveal that TX-NHPIEs can generate one alkyl radical and one N-centered iminyl radical,which can initiate FRP directly and indirectly,respectively.In other words,TX-NHPIEs absorb one photon and can generate two active radicals,which break through the limitations of common PIs.TX-NHPIE-Cpe demonstrates the highest initiating efficiency,and its application in coatings and 3D printing was also studied,indicating TX-NHPIEs have broad potential applications in photopolymerization processes.
基金This work was supported by the National Natural Science Foundation of China(Nos.21876063,22076064 and 22106169)the Guangdong Special Support Program(No.2019TX05L129)+2 种基金the Science and Technology Program of Guangzhou(No.202206010191)the Guangdong(China)Innovative and Entrepreneurial Research Team Program(No.2016ZT06N258)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(No.2019B121205004)。
文摘Photoinitiators(PIs)are widely used in industrial polymerization processes.It has been reported that PIs are ubiquitous in indoor environments and that humans are exposed to PIs,but the occurrence of PIs in natural environments are rarely known.In the present study,25 PIs,including 9 benzophenones(BZPs),8 amine co-initiators(ACIs),4 thioxanthones(TXs)and 4 phosphine oxides(POs),were analyzed in water and sediment samples collected from eight riverine outlets of the Pearl River Delta(PRD).Eighteen,14,and 14 of the 25 target PIs were detected in water,suspended particulatematter(SPM)and sediment samples,respectively.The total concentrations of PIs in water,SPM,and sediment were in the ranges of 2.88–96.1 ng/L,9.25–923 ng/g dry weight(dw),and 3.79–56.9 ng/g dw,with geometric mean concentration(GM)of 10.8 ng/L,48.6 ng/g dw,and 17.1 ng/g dw,respectively.A significant linear regression was observed between the log partitioning coefficients(Kd)values of PIs and their log octanol water partition coefficient(Kow)values(R^(2)=0.535,p<0.05).The annual riverine input of PIs to the coastal waters of the South China Sea via eightmain outlets of the PRD was estimated to be 4.12×10^(3)kg/year,and the∑BZPs,∑ACIs,∑TXs and∑POs contributed to 1.96×10^(3),1.24×10^(3),89.6 and 830 kg/year,respectively.This is the first report of a systematic description of the occurrence characteristics of PIs exposure in water,SPM,and sediment.The environmental fate and risks of PIs in aquatic environments need further investigations.