Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified pH.In this work,we p...Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified pH.In this work,we proposed a simple and very convenient approach to fabricate high strength pH responsive supramolecular polymer(SP) hydrogels by one-pot copolymerization of N-acryloyl glycinamide(NAGA) and 2-vinyl-4,6-diamino-1,3,5-triazine(VDT),two feature hydrogen bonding monomers.In these PNAGA-PVDT SP hydrogels obtained,the hydrogen bonding of NAGA was shown to play a dominant role in reinforcing strength,while the hydrogen bonding of diaminotriazine served as a pH sensitive moiety.At pH 3,the mechanical properties of PNAGA-PVDT hydrogels decreased to a different extent due to the breakup of hydrogen bonding;in contrast,the hydrogel resumed the original strength while pH was raised to 7.4 because of reconstruction of hydrogen bonding.Over the selected pH range,the PNAGA-PVDT hydrogels exhibited up to 1.25 MPa tensile strength,845% breaking strain,69 kPa Young's modulus and 21 MPa compressive strength.This novel high strength pH-responsive SP hydrogels may find applications in biomedical and industrial fields.展开更多
Supramolecular dendritic polymers（SDPs）provide a new opportunity for the precision diagnosis and treatment of diseases. SDPs are a novel class of non-covalently bonded macromolecules with highly branched structure a...Supramolecular dendritic polymers（SDPs）provide a new opportunity for the precision diagnosis and treatment of diseases. SDPs are a novel class of non-covalently bonded macromolecules with highly branched structure and three-dimensional globular topology, which exhibit dynamic/reversible features and unique physical/chemical properties（e.g., high solubility, low viscosity, and numerous functional terminal groups）. The reversibility of non-covalent interactions endows SDPs with the ability of facile preparation, smart responsiveness, and simple metabolism. These special characteristics determine the properties of SDPs, which are the key points for theranostic applications, including diagnosis,therapy, and theranostics. In this review, we briefly summarize the design and synthesis of SDPs with aimed structures,properties, functions as well as their present diagnostic and theranostic applications. These developments on the preparation and applications of SDPs for diagnostic and theranostic purpose promote interdisciplinary research fields of chemistry, material and biomedical science.展开更多
Many technological applications require templates with nanoscale patterns.Block copolymer self-assembly is a method of choice for obtaining a large variety of such patterns,with greatest flexibility achieved when comb...Many technological applications require templates with nanoscale patterns.Block copolymer self-assembly is a method of choice for obtaining a large variety of such patterns,with greatest flexibility achieved when combined with a supramolecular approach.One of the ways to fabricate block copolymer templates is the Langmuir-Blodgett (LB) technique.Here,we briefly summarize recent work with LB films of polystyrene-poly(4-vinyl pyridine) (PS-P4VP) mixed with 3-n-pentade cylphenol (PDP),illustrating the different types of patterns possible and the principles governing them.One interesting pattern that can be easily achieved with this system is the so-called "nanostrand network",which,when used as a template for gold deposition,can produce double striped lines of gold.Here,we show how this pattern can be modified by acetone swelling to give rise to gold monolayer ribbons with internal structure.The results also suggest new insights into the early stages of morphology formation at the air/water interface.展开更多
This contribution shows the strong influence of using chloroform instead of THF on the characteristics of thin films of supramolecular block copolymers of poly(styrene-b-4-vinyl pyridine) dip-coated in the so-called &...This contribution shows the strong influence of using chloroform instead of THF on the characteristics of thin films of supramolecular block copolymers of poly(styrene-b-4-vinyl pyridine) dip-coated in the so-called "capillarity" regime from solutions containing 1-naphthol or 1-naphthoic acid.The small molecule content in the dip-coated films was investigated by infrared spectroscopy and the film morphology by atomic force microscopy.It was found that the small molecule content in the films is constant with dip-coating rate in the range investigated,but it is higher for 1-naphthoic acid than for 1-naphthol.The main morphology observed was in the form of "islands" and "holes",which is typical of flat-on lamellae.These findings are related to hydrogen-bonding between the small molecule and pyridine being conserved in chloroform and to the good solubility of both blocks in this solvent,with differences between the two small molecules related to their differing H-bond strengths.These findings contrast strongly with what was observed previously using THF as a solvent,for which the SM content increases with dip-coating rate and the morphologies are mainly spherical and cylindrical in the same parameter range.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51325305)National Key Research and Development Program(GrantNo.2016YFC1101301)Tianjin Municipal Natural Science Foundation(Grant Nos.13ZCZDSY00900,15JCZDJC38000)
文摘Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified pH.In this work,we proposed a simple and very convenient approach to fabricate high strength pH responsive supramolecular polymer(SP) hydrogels by one-pot copolymerization of N-acryloyl glycinamide(NAGA) and 2-vinyl-4,6-diamino-1,3,5-triazine(VDT),two feature hydrogen bonding monomers.In these PNAGA-PVDT SP hydrogels obtained,the hydrogen bonding of NAGA was shown to play a dominant role in reinforcing strength,while the hydrogen bonding of diaminotriazine served as a pH sensitive moiety.At pH 3,the mechanical properties of PNAGA-PVDT hydrogels decreased to a different extent due to the breakup of hydrogen bonding;in contrast,the hydrogel resumed the original strength while pH was raised to 7.4 because of reconstruction of hydrogen bonding.Over the selected pH range,the PNAGA-PVDT hydrogels exhibited up to 1.25 MPa tensile strength,845% breaking strain,69 kPa Young's modulus and 21 MPa compressive strength.This novel high strength pH-responsive SP hydrogels may find applications in biomedical and industrial fields.
基金financially supported by the National Natural Science Foundation of China (51690151, 51503122, 21374062 and 51473093)National Basic Research Program (2015CB931801)
文摘Supramolecular dendritic polymers（SDPs）provide a new opportunity for the precision diagnosis and treatment of diseases. SDPs are a novel class of non-covalently bonded macromolecules with highly branched structure and three-dimensional globular topology, which exhibit dynamic/reversible features and unique physical/chemical properties（e.g., high solubility, low viscosity, and numerous functional terminal groups）. The reversibility of non-covalent interactions endows SDPs with the ability of facile preparation, smart responsiveness, and simple metabolism. These special characteristics determine the properties of SDPs, which are the key points for theranostic applications, including diagnosis,therapy, and theranostics. In this review, we briefly summarize the design and synthesis of SDPs with aimed structures,properties, functions as well as their present diagnostic and theranostic applications. These developments on the preparation and applications of SDPs for diagnostic and theranostic purpose promote interdisciplinary research fields of chemistry, material and biomedical science.
基金supported by the Natural Sciences and Engineering Council of Canada (NSERC)the Fonds de recherches du Québec-Nature et Technologies (FQRNT)
文摘Many technological applications require templates with nanoscale patterns.Block copolymer self-assembly is a method of choice for obtaining a large variety of such patterns,with greatest flexibility achieved when combined with a supramolecular approach.One of the ways to fabricate block copolymer templates is the Langmuir-Blodgett (LB) technique.Here,we briefly summarize recent work with LB films of polystyrene-poly(4-vinyl pyridine) (PS-P4VP) mixed with 3-n-pentade cylphenol (PDP),illustrating the different types of patterns possible and the principles governing them.One interesting pattern that can be easily achieved with this system is the so-called "nanostrand network",which,when used as a template for gold deposition,can produce double striped lines of gold.Here,we show how this pattern can be modified by acetone swelling to give rise to gold monolayer ribbons with internal structure.The results also suggest new insights into the early stages of morphology formation at the air/water interface.
基金supported by the Natural Sciences and Engineering Council of Canada (NSERC)the Fonds de recherche du Québec-Nature et Technologies (FQRNT)
文摘This contribution shows the strong influence of using chloroform instead of THF on the characteristics of thin films of supramolecular block copolymers of poly(styrene-b-4-vinyl pyridine) dip-coated in the so-called "capillarity" regime from solutions containing 1-naphthol or 1-naphthoic acid.The small molecule content in the dip-coated films was investigated by infrared spectroscopy and the film morphology by atomic force microscopy.It was found that the small molecule content in the films is constant with dip-coating rate in the range investigated,but it is higher for 1-naphthoic acid than for 1-naphthol.The main morphology observed was in the form of "islands" and "holes",which is typical of flat-on lamellae.These findings are related to hydrogen-bonding between the small molecule and pyridine being conserved in chloroform and to the good solubility of both blocks in this solvent,with differences between the two small molecules related to their differing H-bond strengths.These findings contrast strongly with what was observed previously using THF as a solvent,for which the SM content increases with dip-coating rate and the morphologies are mainly spherical and cylindrical in the same parameter range.
