In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, t...In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, then droping water into the corresponding copolymer solution to induce the self-assembly. The aggregates prepared were characterized with TEM and AFM techniques. The experimental results demonstrated that the self-assembled vesicles were formed when THF and 1,4-dioxane were used as the common solvents to dissolve the copolymer, comparatively, using DMF as the common solvent resulted in the formation of spherical aggregates. The self-assembled aggregates observed, possessing hierarchical structures, could be used as either the nanostructures themselves for drug delivery systems, separations, catalysts, and so on, or templates or building blocks for more complex structures.展开更多
Amphiphilic diblock copolymers containing glycopolymer segments, polystyrene block poly[2 ( β D glucopyranosyloxy)ethylacrylate](PS b PGEA), were synthesized by atom transfer radical polymerization. The morphologies ...Amphiphilic diblock copolymers containing glycopolymer segments, polystyrene block poly[2 ( β D glucopyranosyloxy)ethylacrylate](PS b PGEA), were synthesized by atom transfer radical polymerization. The morphologies of the crew cut aggregates of PS b PGEA in water were studied by TEM. It has been found that for one specific diblock copolymer, the morphological transformation from spheres to vesicles was controllable by changing solvents. Spheres, rods and vesicles were found to be the dominant morphologies for PS 55 b PGEA 9 when the solvents were DMF, DMF/1,4 doxane and 1,4 dioxane respectively. When same solvent, e.g . 1,4 dioxane, was used, sphere to vesicle transition of crew cut aggregates was also obtainable by using diblock copolymers of different compositions. The copolymers with a higher hydrophilic segment content tend to form spheres, while those with a lower content yield predominated vesicles.展开更多
To enhance the anesthetic efficacy and reduce toxic side effects,a strategy is proposed involving the utilization of general anesthetics of Propofol(Pro)and Eto-midate(Eto)to synergistic inhibition GABA receptors simul...To enhance the anesthetic efficacy and reduce toxic side effects,a strategy is proposed involving the utilization of general anesthetics of Propofol(Pro)and Eto-midate(Eto)to synergistic inhibition GABA receptors simultaneously.Four-in-one molecular aggregates were prepared to implement this strategy,which comprised of Pro and Eto with the bridging molecule monoglyceride monooleate(GMO)and sur-factant F127 through intermolecular forces.The blood-brain barrier(BBB)targeted lactoferrin(LF)is affixed to their surface,obtaining thefinal molecular aggregates.By employing lactoferrin enrich aggregates to the BBB,followed by ultrasound combine microbubbles to open the BBB,a remarkable 4.5-fold enhancement in brain drug delivery was achieved.The molecular aggregates group maintained sta-ble parameters of heart rate,diastolic blood pressure,and systolic blood pressure.A notable increase of more than twice therapeutic index(TI)value was observed,implying their higher anesthesia efficiency and reduced toxicity.Electroencephalo-gram(EEG)experiments demonstrate a significant elevation in the proportion of θ waves from 28%to 80%for aggregates,accompanied by a nearlyfivefold reduc-tion in the proportion ofθwaves,meaning a significant improvement in synergistic anesthesia effectiveness(interaction index 0.289)with lower drug dosage.Further-more,mouse immunofluorescence brain slice experiments suggest Pro and Eto enter the GABA receptor simultaneously,resulting in synergistic inhibition of GABA receptors.展开更多
Asphaltenes generally exist in the form of molecular aggregates in crude oil or in petroleum residues,and asphaltene aggregates can usually cause serious problems to oil exploitation,transportation,and processing.Achi...Asphaltenes generally exist in the form of molecular aggregates in crude oil or in petroleum residues,and asphaltene aggregates can usually cause serious problems to oil exploitation,transportation,and processing.Achieving deaggregation and separation of asphaltene aggregates is a premise and basis for molecular characterization and processing of heavy oils.Aiming at the intermolecular interactions in asphaltene molecular aggregates,it has proposed and summarized that aspahltene aggregates can be subject to deaggregation by means of five approaches,including solvent diluting,removing active sites,moderate heating,ultrasonication and on-line molecular collision.Moreover,asphaltenes can be further separated to narrow fractions for molecular-level research based on polarity difference,molecular size difference,acid-base properties,and reactivity difference.展开更多
This project aims to attack the frontiers of electronic structure calculations on the excited states of large molecules and molecular aggregates by developing novel theoretical and computational methods. The methodolo...This project aims to attack the frontiers of electronic structure calculations on the excited states of large molecules and molecular aggregates by developing novel theoretical and computational methods. The methodology development is especially based on the time-dependent density functional theory (TDDFT) and valence bond (VB) theory, and is expected to be computationally effective and accurate as well. Research works on the following related subjects will be performed: (1) The analytical energy-derivative approaches for electronically excited state within TDDFT will be developed to reduce bypass the computational costs in the calculation of molecular excited-state properties. (2) The ab initio methods for electronically excited state based on VB theory and hybrid TDDFT-VB method will be developed to overcome the limitations of current TDDFT in simulating photophysics and photochemistry. (3) For larger aggregates, neither ab initio methods nor TDDFT is applicable. We intend to build the effective model Hamiltonian by developing novel theoretical and computational methods to calculate the involved microscopic physical parameters from the first-principles methods. The constructed effective Hamiltonian is then used to describe the excitonic states and excitonic dynamics of the natural or artificial photosynthesized systems, organic or inorganic photovoltaic cell. (4) The condensed phase environment is taken into account by combining the developed theories and algorithms based on TDDFT and VB with the polarizable continuum solvent models (PCM), molecular mechanism (MM), classical electrodynamics (ED) or molecular dynamics (MD) theory. (5) Highly efficient software packages will be designed and developed.展开更多
Molecular interactions are crucial in diverse fields of protein folding,material science,nanotechnology,and life origins.Although mounting experimental research controls luminescent behavior by adjusting molecular int...Molecular interactions are crucial in diverse fields of protein folding,material science,nanotechnology,and life origins.Although mounting experimental research controls luminescent behavior by adjusting molecular interactions in light-emitting materials,it remains elusive to correlate microscopic molecular interactions with macroscopic luminescent behavior directly.Here,we synthesized three red luminogens with subtle structural variation and investigated the influence of molecular interactions on their luminescent behavior in solution and aggregate states.Our results indicate that strongπ-πand D-A interactions in both dilute solution(between luminogen and solvent molecules)and aggregate(between luminogens)states cause the redshift in emission,while weak interactions(e.g.,Van der Waals,C–H…π,and C–H…F interactions)enhance the quantum yield.This work provides a thoughtful investigation into the complicated influence of various molecular interactions on luminescent behavior.展开更多
We present here a brief summary of a National Natural Science Foundation Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". The project focuses on ...We present here a brief summary of a National Natural Science Foundation Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". The project focuses on theoretical investigation of the electronic structures and dynamic processes upon photo-and electric-excitation for molecules and aggregates. We aim to develop reliable methodology to predict the optoelectronic properties of molecular materials related to the electronic excitations and to apply in the experiments. We identify two essential scientific challenges: (i) nature of intramolecular and intermolecular electronic excited states; (ii) theoretical description of the dynamic processes of the coupled motion of electronic excitations and nucleus. We propose the following four subjects of research: (i) linear scaling time-dependent density-functional theory and its application to open shell system; (ii) computational method development of electronic excited state for molecular aggregates; (iii) theoretical investigation of the time evolution of the excited state dynamics; (iv) methods to predict the optoelectronic properties starting from electronic excited state investigation for organic materials and experimental verifications.展开更多
This contribution provides a summary of proposed theoretical and computational studies on excited state dynamics in molecular aggregates, as an important part of the National Natural Science Foundation (NNSF) Major Pr...This contribution provides a summary of proposed theoretical and computational studies on excited state dynamics in molecular aggregates, as an important part of the National Natural Science Foundation (NNSF) Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". This study will focus on developments of novel methods to simulate excited state dynamics of molecular aggregates, with the aim of understanding several important chemical physics processes, and providing a solid foundation for predicting the opto-electronic properties of organic functional materials and devices. The contents of this study include: (1) The quantum chemical methods for electronic excited state and electronic couplings targeted for dynamics in molecular aggregates; (2) Methods to construct effective Hamiltonian models, and to solve their dynamics using system-bath approaches; (3) Non-adiabatic mixed quantum-classic methods targeted for molecular aggregates; (4) Theoretical studies of charge and energy transfer, and related spectroscopic phenomena in molecular aggregates.展开更多
Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(k_(nr)) governed by the energy gap law. To date, reported endeavors to...Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(k_(nr)) governed by the energy gap law. To date, reported endeavors to decelerate k_(nr) are mainly focused on reducing the electron-vibration coupling with the electronic nonadiabatic coupling assumed as a constant. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer(CT) aggregates(CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states;thereby, not only reducing the electronic nonadiabatic coupling and contributing to small k_(nr) for high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for highefficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.展开更多
文摘In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, then droping water into the corresponding copolymer solution to induce the self-assembly. The aggregates prepared were characterized with TEM and AFM techniques. The experimental results demonstrated that the self-assembled vesicles were formed when THF and 1,4-dioxane were used as the common solvents to dissolve the copolymer, comparatively, using DMF as the common solvent resulted in the formation of spherical aggregates. The self-assembled aggregates observed, possessing hierarchical structures, could be used as either the nanostructures themselves for drug delivery systems, separations, catalysts, and so on, or templates or building blocks for more complex structures.
文摘Amphiphilic diblock copolymers containing glycopolymer segments, polystyrene block poly[2 ( β D glucopyranosyloxy)ethylacrylate](PS b PGEA), were synthesized by atom transfer radical polymerization. The morphologies of the crew cut aggregates of PS b PGEA in water were studied by TEM. It has been found that for one specific diblock copolymer, the morphological transformation from spheres to vesicles was controllable by changing solvents. Spheres, rods and vesicles were found to be the dominant morphologies for PS 55 b PGEA 9 when the solvents were DMF, DMF/1,4 doxane and 1,4 dioxane respectively. When same solvent, e.g . 1,4 dioxane, was used, sphere to vesicle transition of crew cut aggregates was also obtainable by using diblock copolymers of different compositions. The copolymers with a higher hydrophilic segment content tend to form spheres, while those with a lower content yield predominated vesicles.
基金Young Top-notch Talents of“High-level Talents Special Support Program”of Shaanxi ProvinceNational Natural Science Foundation of China,Grant/Award Numbers:81971290,82102074。
文摘To enhance the anesthetic efficacy and reduce toxic side effects,a strategy is proposed involving the utilization of general anesthetics of Propofol(Pro)and Eto-midate(Eto)to synergistic inhibition GABA receptors simultaneously.Four-in-one molecular aggregates were prepared to implement this strategy,which comprised of Pro and Eto with the bridging molecule monoglyceride monooleate(GMO)and sur-factant F127 through intermolecular forces.The blood-brain barrier(BBB)targeted lactoferrin(LF)is affixed to their surface,obtaining thefinal molecular aggregates.By employing lactoferrin enrich aggregates to the BBB,followed by ultrasound combine microbubbles to open the BBB,a remarkable 4.5-fold enhancement in brain drug delivery was achieved.The molecular aggregates group maintained sta-ble parameters of heart rate,diastolic blood pressure,and systolic blood pressure.A notable increase of more than twice therapeutic index(TI)value was observed,implying their higher anesthesia efficiency and reduced toxicity.Electroencephalo-gram(EEG)experiments demonstrate a significant elevation in the proportion of θ waves from 28%to 80%for aggregates,accompanied by a nearlyfivefold reduc-tion in the proportion ofθwaves,meaning a significant improvement in synergistic anesthesia effectiveness(interaction index 0.289)with lower drug dosage.Further-more,mouse immunofluorescence brain slice experiments suggest Pro and Eto enter the GABA receptor simultaneously,resulting in synergistic inhibition of GABA receptors.
文摘Asphaltenes generally exist in the form of molecular aggregates in crude oil or in petroleum residues,and asphaltene aggregates can usually cause serious problems to oil exploitation,transportation,and processing.Achieving deaggregation and separation of asphaltene aggregates is a premise and basis for molecular characterization and processing of heavy oils.Aiming at the intermolecular interactions in asphaltene molecular aggregates,it has proposed and summarized that aspahltene aggregates can be subject to deaggregation by means of five approaches,including solvent diluting,removing active sites,moderate heating,ultrasonication and on-line molecular collision.Moreover,asphaltenes can be further separated to narrow fractions for molecular-level research based on polarity difference,molecular size difference,acid-base properties,and reactivity difference.
基金the National Natrual Science Foundation of China (21290193)
文摘This project aims to attack the frontiers of electronic structure calculations on the excited states of large molecules and molecular aggregates by developing novel theoretical and computational methods. The methodology development is especially based on the time-dependent density functional theory (TDDFT) and valence bond (VB) theory, and is expected to be computationally effective and accurate as well. Research works on the following related subjects will be performed: (1) The analytical energy-derivative approaches for electronically excited state within TDDFT will be developed to reduce bypass the computational costs in the calculation of molecular excited-state properties. (2) The ab initio methods for electronically excited state based on VB theory and hybrid TDDFT-VB method will be developed to overcome the limitations of current TDDFT in simulating photophysics and photochemistry. (3) For larger aggregates, neither ab initio methods nor TDDFT is applicable. We intend to build the effective model Hamiltonian by developing novel theoretical and computational methods to calculate the involved microscopic physical parameters from the first-principles methods. The constructed effective Hamiltonian is then used to describe the excitonic states and excitonic dynamics of the natural or artificial photosynthesized systems, organic or inorganic photovoltaic cell. (4) The condensed phase environment is taken into account by combining the developed theories and algorithms based on TDDFT and VB with the polarizable continuum solvent models (PCM), molecular mechanism (MM), classical electrodynamics (ED) or molecular dynamics (MD) theory. (5) Highly efficient software packages will be designed and developed.
基金supported by the National Natural Science Foundation of China(21788102,52003228)the Innovation and Technology Commission(ITC-CNERC14SC01)+1 种基金the Research Grants Council of Hong Kong(16307020,C6009-17G,C6014-20W,and N-HKUST609/19)the Natural Science Foundation of Guangdong Province(2019B121205012)。
文摘Molecular interactions are crucial in diverse fields of protein folding,material science,nanotechnology,and life origins.Although mounting experimental research controls luminescent behavior by adjusting molecular interactions in light-emitting materials,it remains elusive to correlate microscopic molecular interactions with macroscopic luminescent behavior directly.Here,we synthesized three red luminogens with subtle structural variation and investigated the influence of molecular interactions on their luminescent behavior in solution and aggregate states.Our results indicate that strongπ-πand D-A interactions in both dilute solution(between luminogen and solvent molecules)and aggregate(between luminogens)states cause the redshift in emission,while weak interactions(e.g.,Van der Waals,C–H…π,and C–H…F interactions)enhance the quantum yield.This work provides a thoughtful investigation into the complicated influence of various molecular interactions on luminescent behavior.
基金the National Natural Science Foundation of China (21290190)
文摘We present here a brief summary of a National Natural Science Foundation Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". The project focuses on theoretical investigation of the electronic structures and dynamic processes upon photo-and electric-excitation for molecules and aggregates. We aim to develop reliable methodology to predict the optoelectronic properties of molecular materials related to the electronic excitations and to apply in the experiments. We identify two essential scientific challenges: (i) nature of intramolecular and intermolecular electronic excited states; (ii) theoretical description of the dynamic processes of the coupled motion of electronic excitations and nucleus. We propose the following four subjects of research: (i) linear scaling time-dependent density-functional theory and its application to open shell system; (ii) computational method development of electronic excited state for molecular aggregates; (iii) theoretical investigation of the time evolution of the excited state dynamics; (iv) methods to predict the optoelectronic properties starting from electronic excited state investigation for organic materials and experimental verifications.
基金the National Natural Science Foundation of China (21290194)
文摘This contribution provides a summary of proposed theoretical and computational studies on excited state dynamics in molecular aggregates, as an important part of the National Natural Science Foundation (NNSF) Major Project entitled "Theoretical study of the low-lying electronic excited state for molecular aggregates". This study will focus on developments of novel methods to simulate excited state dynamics of molecular aggregates, with the aim of understanding several important chemical physics processes, and providing a solid foundation for predicting the opto-electronic properties of organic functional materials and devices. The contents of this study include: (1) The quantum chemical methods for electronic excited state and electronic couplings targeted for dynamics in molecular aggregates; (2) Methods to construct effective Hamiltonian models, and to solve their dynamics using system-bath approaches; (3) Non-adiabatic mixed quantum-classic methods targeted for molecular aggregates; (4) Theoretical studies of charge and energy transfer, and related spectroscopic phenomena in molecular aggregates.
基金the National Natural Science Foundation of China(51773109,21788102)National Key R&D Program of China(2020YFA0715001,2017YFA0204501)+1 种基金National Postdoctoral Program for Innovative Talents(BX20180159)the Project funded by China Postdoctoral Science Foundation(2019M660606)。
文摘Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(k_(nr)) governed by the energy gap law. To date, reported endeavors to decelerate k_(nr) are mainly focused on reducing the electron-vibration coupling with the electronic nonadiabatic coupling assumed as a constant. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer(CT) aggregates(CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states;thereby, not only reducing the electronic nonadiabatic coupling and contributing to small k_(nr) for high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for highefficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.
