Co-reporter:Yeqiang Lu and Weizhong Yuan
ACS Applied Materials & Interfaces August 30, 2017 Volume 9(Issue 34) pp:29167-29167
Publication Date(Web):August 10, 2017
DOI:10.1021/acsami.7b09160
Superhydrophobic/superoleophilic and reinforced ethyl cellulose (SEC) sponges were prepared by cross-linking EC with epichlorohydrin (ECH) and complexing with silanized carbon nanotubes (Si-CNTs) followed by coating nanosilica on the surface of porous sponges and subsequent modification with hexadecyltrimethoxysilane (HDTMS). These synergistic strategies endowed the SEC sponges with the superhydrophobic/superoleophilic properties (θwater = 158.2°, θoil = 0°, sliding angle = 3°) and outstanding mechanical properties (could bear the pressure of 28.6 kPa without damage). The unique micronanostructures and properties of the porous sponges were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and water contact angle measurements. The as prepared SEC sponges with high mechanical strength were able to collect a wide range of oils and organic solvents with absorption capacity up to 64 times of their own weight. Furthermore, the absorption capacity of the sponges decreased slightly to 86.4% of its initial value after 50 separation cycles, suggesting their excellent recyclable performance. The high efficiency and endurability of the sponges during oil/water separation made them ideal absorbent in oil spillage cleanup.Keywords: carbon nanotube composite; cross-linking; ethyl cellulose; oil/water separation; reinforcement; superhydrophobic/superoleophilic;
Co-reporter:Hui Zou;Yeqiang Lu;Shanfeng Wang
Chemical Communications 2017 vol. 53(Issue 16) pp:2463-2466
Publication Date(Web):2017/02/21
DOI:10.1039/C6CC09959A
UV light- and thermo-responsive supramolecular aggregates with tunable morphologies were obtained through the inclusion complexation between a β-CD containing dendritic host polymer and an azobenzene containing linear guest polymer. Morphologies of the aggregates could be adjusted by changing the molar ratio of host/guest polymers in the supramolecular polymers.
Co-reporter:Hui Zou;Yeqiang Lu;Shanfeng Wang
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 4) pp:661-665
Publication Date(Web):2017/01/24
DOI:10.1039/C6PY02016J
UV light and thermo-responsive hierarchical assemblies have been achieved based on the inclusion complexation between β-cyclodextrin and azobenzene. The conformation and morphology of the hierarchical assemblies were modulatable through external stimuli. These hierarchical assemblies have the advantages of their unique structure and precisely adjusted dual responses.
Co-reporter:Jiangdi Chen;Zixuan Zhou;Zixun Chen;Maoquan Li
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 18) pp:10272-10280
Publication Date(Web):2017/09/11
DOI:10.1039/C7NJ01263B
A well-dispersed chemosensor based on cellulose nanocrystals (CNCs) with porphyrin pendants (CNC-SA-COOC6TPP) was facilely synthesized by the combination of carboxylation, extended esterification and dicyclohexylcarbodiimide (DCC) reaction. The CNC-SA-COOC6TPP nanomaterials promoted the solubility of porphyrin groups in water and the nanomaterials could be easily separated from water by filtering. The structure of CNC-SA-COOC6TPP nanomaterials could be verified by FT-IR, 1H NMR and XPS characterization. The TEM images showed that CNC-SA-COOC6TPP nanomaterials presented needle-like morphologies. The unique properties of high sensitivity and selectivity for Hg2+ of porphyrin-modified CNCs were investigated separately via fluorescence emission spectroscopy under characteristic excitation wavelengths of porphyrin moieties. Further investigation revealed that CNC-SA-COOC6TPP nanomaterials (0.01 wt% in H2O) could specifically detect Hg2+ with a detection limit for Hg2+ of ca. 5.0 × 10−8 mol L−1 (50 nM). In addition, Hg2+ was specifically detected with interference from other metal ions, which was attributed to the specific formation of the Hg2+–porphyrin complex with an interaction stoichiometry of one Hg2+ per porphyrin moiety. The concentration of all other metal ions could be qualitatively detected based on the relationship between fluorescence intensity and concentration. As a result, the good dispersion of cellulose nanocrystals and the high selectively and sensitivity of porphyrin pendants resulted in the highly efficient detection of Hg2+ in water, which makes CNC-SA-COOC6TPP a promising fluorescence chemosensor.
Co-reporter:Yeqiang Lu, Hui Zou, Hua Yuan, Shuying Gu, Weizhong Yuan, Maoquan Li
European Polymer Journal 2017 Volume 91(Volume 91) pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.eurpolymj.2017.04.028
•The host polymer β-CD-P(MEO2MA-co-OEGMA) was prepared by click chemistry and ATRP.•The guest polymer Azo-PCL-SS-PEG was synthesized by ROP and esterification reaction.•The amphiphilic supramolecular polymer can self-assemble into spherical micelles in water.•The micelles presented obvious UV light-, thermo- and redox-responsive properties.The host polymer β-cyclodextrin-poly[(2-(2-methoxyethoxy)ethylmethacrylate)-co-oligo(ethylene glycol) methacrylate] [β-CD-P(MEO2MA-co-OEGMA)] was prepared by click chemistry and atom transfer radical polymerization (ATRP), and the guest polymer poly(ε-caprolactone)-SS-poly(ethylene glycol) with azobenzene (Azo) group at one end (Azo-PCL-SS-PEG) was synthesized by the combination of ring-opening polymerization (ROP) and esterification reaction. Based on the inclusion complexation between β-CD and Azo groups, the supramolecular polymer β-CD-P(MEO2MA-co-OEGMA)/Azo-PCL-SS-PEG was successfully obtained. Benefitting from the amphiphilicity, the supramolecular polymer could self-assemble into spherical micelles in aqueous solution, and the supramolecular micelles presented obvious UV light-, thermo- and redox-responsive properties. Alternating irradiation of the solution with UV or visible light could induce the reversible supramolecular self-assembly and disassembly of the micelles. When the temperature of the solution increased above the lower critical solution temperature (LCST) of P(MEO2MA-co-OEGMA) chains, the micelles became smaller and aggregated with each other. Moreover, after adding DTT into the micellar solution, the spherical micelles changed into irregular aggregates.Download high-res image (137KB)Download full-size image
Co-reporter:Yeqiang Lu, Yue Wang, Lejing Liu, Weizhong Yuan
Carbohydrate Polymers 2017 Volume 173(Volume 173) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.carbpol.2017.06.009
•Environmental-friendly superhydrophobic magnetic ethyl cellulose sponges were fabricated.•The sponges showed excellent hydrophobicity and oleophilicity.•The oil-absorption capabilities of the sponges were studied.•The excellent oil-absorption capability could be maintained even after fifty cycles.Ethyl cellulose (EC), owing to its wide availability, environmental-friendliness, and intrinsic hydrophobicity/oleophilicity, was used as an absorbent material for the first time. The superhydrophobic magnetic EC sponges with low density and high porosity were facilely prepared via freeze-drying method. The superhydrophobicity and magnetism of the sponges were achieved by silanization EC with hexadecyltrimethoxysilane and mixing with ferroferric oxide (Fe3O4) nanoparticles. The as-prepared magnetic silanized EC (MSEC) sponges showed stable superhydrophobicity (θwater > 150°, rolling contact angle: 7°) in several kinds of solutions. Furthermore, the sponges exhibited high separation efficiency and good mass absorption capacity for a wide variety of oils and organic solvents (37–51 times of their own weight). Benefitting from the robust superhydrophobicity and good self-cleaning property of the sponges, the absorption capacity could be well maintained upon repeated use, demonstrating the superior recyclability. These advantages made the sponges ideal absorbents for oil spillage cleanup.
Co-reporter:Hui Zou;Chunyao Wang;Shanfeng Wang;Maoquan Li
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 33) pp:4869-4877
Publication Date(Web):2017/08/22
DOI:10.1039/C7PY01093A
A glucose-, thermo-, and pH-triple responsive copolymer, poly(2-phenylboronic esters-1,3-dioxane-5-ethyl) methylacrylate-b-poly(2-(N,N-dimethylamino)ethyl methacrylate) (PPBDEMA-b-PDMAEMA), was synthesized through atom transfer radical polymerization (ATRP). Benefiting from its amphiphilicity, PPBDEMA-b-PDMAEMA could self-assemble in water into micelles with the PPBDEMA core and the PDMAEMA shell. Glucose would react with PPBDEMA, leading to the expansion of the micelles. Because of the thermo-responsive PDMAEMA segment, increasing temperature would cause the PDMAEMA shell to shrink and the micelles to aggregate. Both PPBDEMA and PDMAEMA segments were found to have pH-responsive properties, but PDMAEMA responded faster than PPBDEMA upon pH stimulus. When the pH value was high (>8), the original copolymer micelles would disassemble and new micelles with the PPBDEMA shell and the PDMAEMA core would form after 48 h. PPBDEMA-b-PDMAEMA copolymer micelles could be used as smart carriers to achieve the multi-controlled release of insulin and Nile red fluorescent dye molecules by adjusting the temperature, the pH value, and the glucose concentration. The release rate of insulin from the micelles at high glucose concentrations was much faster than that at lower glucose concentrations at the physiological pH value and could be further accelerated by heating. Meanwhile, increasing the temperature, the pH value, and the glucose concentration would increase the release rate of Nile red from the micelles.
Co-reporter:Hui Zou;Chunyao Wang;Shanfeng Wang;Maoquan Li
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 33) pp:4869-4877
Publication Date(Web):2017/08/22
DOI:10.1039/C7PY01093A
A glucose-, thermo-, and pH-triple responsive copolymer, poly(2-phenylboronic esters-1,3-dioxane-5-ethyl) methylacrylate-b-poly(2-(N,N-dimethylamino)ethyl methacrylate) (PPBDEMA-b-PDMAEMA), was synthesized through atom transfer radical polymerization (ATRP). Benefiting from its amphiphilicity, PPBDEMA-b-PDMAEMA could self-assemble in water into micelles with the PPBDEMA core and the PDMAEMA shell. Glucose would react with PPBDEMA, leading to the expansion of the micelles. Because of the thermo-responsive PDMAEMA segment, increasing temperature would cause the PDMAEMA shell to shrink and the micelles to aggregate. Both PPBDEMA and PDMAEMA segments were found to have pH-responsive properties, but PDMAEMA responded faster than PPBDEMA upon pH stimulus. When the pH value was high (>8), the original copolymer micelles would disassemble and new micelles with the PPBDEMA shell and the PDMAEMA core would form after 48 h. PPBDEMA-b-PDMAEMA copolymer micelles could be used as smart carriers to achieve the multi-controlled release of insulin and Nile red fluorescent dye molecules by adjusting the temperature, the pH value, and the glucose concentration. The release rate of insulin from the micelles at high glucose concentrations was much faster than that at lower glucose concentrations at the physiological pH value and could be further accelerated by heating. Meanwhile, increasing the temperature, the pH value, and the glucose concentration would increase the release rate of Nile red from the micelles.
Co-reporter:Hua Yuan, Hai Chi and Weizhong Yuan
Polymer Chemistry 2016 vol. 7(Issue 30) pp:4901-4911
Publication Date(Web):29 Jun 2016
DOI:10.1039/C6PY00702C
Star-shaped amphiphilic poly(ε-caprolactone)-SS-poly(N,N-dimethylaminoethyl methacrylate) (SPCL-SS-PDMAEMA) was synthesized by a combination of ring-opening polymerization (ROP), dicyclohexylcarbodiimide (DCC) reaction and atom transfer radical polymerization (ATRP). After the quaternization reaction of the PDMAEMA segment with excess 1,3-propane sultone, poly(ε-caprolactone)-SS-poly(3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate) (SPCL-SS-PDMAPS) was obtained. The star-shaped structure of the copolymers and the presence of the amorphous PDMAEMA and PDMAPS in copolymers decreased or even completely suppressed the crystallizability of PCL in copolymers. These copolymers could self-assemble into spherical micelles in water. The thermoresponsive micelle solutions showed transition from a lower critical solution temperature (LCST) of SPCL-SS-PDMAEMA to an upper critical solution temperature (UCST) of SPCL-SS-PDMAPS, indicating that the LCST–UCST transition of the micellar solutions can be accomplished by the transition of PDMAEMA to PDMAPS. Moreover, a redox-responsive investigation showed that the distributions of hydrodynamic radius (Rh) broadened with the emergence of aggregates when DL-dithiothreitol (DTT) was added into the micellar systems, since DTT would cause the breakage of disulfide bonds linking PCL and the PDMAEMA/PDMAPS blocks in copolymers.
Co-reporter:Weizhong Yuan, Hui Zou, Jin Shen
Carbohydrate Polymers 2016 Volume 136() pp:216-223
Publication Date(Web):20 January 2016
DOI:10.1016/j.carbpol.2015.09.052
•Amphiphilic ethyl cellulose-based brush copolymers were synthesized by ATRP.•These brush copolymers can self-assemble to micelles.•The micelles presented switchable temperature–CO2 dually responsive properties.•The micelles could achieve the control release of DOX.Amphiphilic ethyl cellulose-graft-poly(N,N-dimethylaminoethyl methacrylate) (EC-g-PDMAEMA) and ethyl cellulose-graft-poly(2-(2-methoxyethoxy)ethyl methacrylate-co-N,N-dimethylaminoethyl methacrylate) (EC-g-P(MEO2MA-co-DMAEMA)) graft copolymers were easily synthesized by atom transfer radical polymerization (ATRP). The micelles self-assembled from the copolymer presented switchable temperature–CO2 dually responsive properties. The value of lower critical solution temperature (LCST) for the copolymer micelle solutions could be adjusted by CO2/Ar. Moreover, due to the alteration of the ratio of DMAEMA to MEO2MA, the LCST values of the micelle solutions decreased with the increase of MEO2MA in copolymer. The temperature–CO2 dually responsive properties of the copolymer were reversible and could be accomplished through altering the temperature and bubbling CO2/Ar. The hydrodynamic radius (Rh) of the copolymer micelles was also influenced by the ratio of DMAEMA to MEO2MA and the stimuli of temperature and CO2/Ar. As a drug release system, the copolymer micelles could achieve the control release of doxorubicin (DOX) by changing the temperature and alternatively bubbling CO2/Ar.
Co-reporter:Hua Yuan, Hai Chi, Weizhong Yuan
Carbohydrate Polymers 2016 Volume 147() pp:261-271
Publication Date(Web):20 August 2016
DOI:10.1016/j.carbpol.2016.04.013
•EC-based graft copolymers were synthesized by ROP and ATRP.•The amphiphilic copolymers can achieve LCST-UCST transition.•The copolymers can self-assemble to micelles.•The hydrophilic-hydrophobic property of the polymers can be adjusted.Novel and well-defined graft copolymer with block copolymer side chain, ethyl cellulose-graft-(poly(ε-caprolactone)-block-poly(N,N-dimethylaminoethylmeth acrylate)) (EC-g-(PCL-b-PDMAEMA)) with a lower critical solution temperature (LCST) was successfully synthesized via the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). EC-g-(PCL-b-PDMAEMA) copolymers with various PCL-b-PDMAEMA block lengths were obtained by adjusting the molar ratios of the N,N-dimethylaminoethyl methacrylate monomer to ε-caprolactone. The EC-g-(PCL-b-PDMAPS) with an upper critical solution temperature (UCST) was obtained via facile quaternization reaction of PDMAEMA with 1,3-propane sultone. EC-g-(PCL-b-PDMAEMA) and EC-g-(PCL-b-PDMAPS) micelle solutions showed opposite thermoresponsiviness and hydrophilic-hydrophobic surface. Moreover, the tunable crystalline morphologies could be obtained from these graft copolymers through changing the polymer structure and PDMAEMA contents.
Co-reporter:Weizhong Yuan and Xiangnan Chen
RSC Advances 2016 vol. 6(Issue 8) pp:6802-6810
Publication Date(Web):08 Jan 2016
DOI:10.1039/C5RA21647H
Star-shaped copolymer poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) with a porphyrin core (THPP(-PDMAEMA-Br)4) was synthesized by atom transfer radical polymerization (ATRP). After reaction with excess NaN3, THPP(-PDMAEMA-Br)4 was transformed to THPP(-PDMAEMA-N3)4. Star-block copolymer THPP(-PDMAEMA-b-PEG)4 was obtained by click reaction of THPP(-PDMAEMA-N3)4 and alkynyl poly(ethylene glycol) (alkynyl PEG). After reaction of the PDMAEMA segment with excess 1,3-propane sultone, the quaternized THPP(-PDMAEMA-Br)4 (THPP(-PDMAPS-Br)4) and quaternized THPP(-PDMAPS-b-PEG)4 were obtained. These copolymers can self-assemble into spherical micelles by directly dissolving in water. The thermoresponsive micelle solutions showed transition from a lower critical solution temperature (LCST) of THPP(-PDMAEMA-Br)4 and THPP(-PDMAEMA-b-PEG)4 to an upper critical solution temperature (UCST) of THPP(-PDMAPS-Br)4 and THPP(-PDMAPS-b-PEG)4, indicating that the LCST–UCST transition of the micellar solutions can be accomplished by the transition of PDMAEMA to PDMAPS. Furthermore, the presence of permanent hydrophilic PEG chains in star-block copolymers changed the values of LCST, UCST and hydrodynamic radius (Rh) of micelles. The micelle solutions presented obvious fluorescence performance. The fluorescence intensity decreased with the increase of temperature, indicating that the variation of temperature could alter the fluorescence intensity of these copolymer micelle solutions.
Co-reporter:Weizhong Yuan;Weiwei Huang;Hui Zou
Polymer Bulletin 2016 Volume 73( Issue 8) pp:2199-2210
Publication Date(Web):2016 August
DOI:10.1007/s00289-016-1603-9
Amphiphilic block copolymer of poly(ethylene glycol) and polymer containing N′-Propargyl-N,N-dimethylacetamidines (PEG-b-PADS) was easily synthesized via the combination of reversible addition-fragmentation chain transfer polymerization (RAFT) and click chemistry. The structure of the copolymer was characterized by nuclear magnetic resonance (1H NMR) and attenuated total internal reflectance fourier transform infrared spectroscopy (ATR FT-IR). As an amphiphilic copolymer, PEG-b-PADS can self-assemble to micelles with PEG shell and PADS core in aqueous medium, and its self-assembly behavior and CO2-responsive properties were investigated by transmission electron microscopy (TEM) and dynamic light scatting (DLS). The size and morphologies of the micelles can be controlled by bubbling CO2 or Ar into the solution. Alternating treatment with CO2 and Ar could realize a reversible contraction–expansion transformation of the micelles. As a carrier for drug delivery systems, the micelles showed good controlled release behavior for drug molecules. Investigation shows that the release rate and level of doxorubicin (DOX) could be controlled through bubbling with CO2 and Ar alternatively.
Co-reporter:Hui Zou and Weizhong Yuan
Journal of Materials Chemistry A 2015 vol. 3(Issue 2) pp:260-269
Publication Date(Web):03 Nov 2014
DOI:10.1039/C4TB01518E
An amphiphilic PCL-SS-PDMAEMA copolymer was synthesized by the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) using a new disulfide functionalized double-head initiator with both terminal hydroxyl and bromine groups. Based on the self-assembly of the PCL-SS-PDMAEMA copolymer with oleic acid modified Fe3O4 nanoparticles in aqueous solutions, magnetic PCL-SS-PDMAEMA/Fe3O4 complex micelles with a saturation magnetization of 10.20 emu g−1 were prepared. The investigation of magnetothermal properties of the magnetic complex micelles showed that the temperature of the magnetic micellar systems increased in the alternating magnetic field (AMF) and the increasing rate and steady-state temperature could be adjusted through altering the magnetic flux density. Benefitting from the thermal response of PDMAEMA and redox response of the disulfide bond, the magnetic complex micelles presented obvious temperature- and redox-responsive properties. The Rh of the magnetic complex micelles would decrease when the micellar solutions were heated. And when DTT was added into the magnetic micellar systems, the distributions of Rh broadened with the emergence of aggregates. Due to the magnetic, magnetothermal, temperature- and redox-responsive properties, the magnetic complex micelles were used as a carrier for drug delivery systems. Doxorubicin (DOX), an anticancer drug, was used as a model drug and loaded into the magnetic complex micelles. The magnetic complex micelles presented good properties for controlled release. The release rate and level could be controlled by adding an external AMF and altering the DTT concentration.
Co-reporter:Hui Zou and Weizhong Yuan
Polymer Chemistry 2015 vol. 6(Issue 13) pp:2457-2465
Publication Date(Web):22 Jan 2015
DOI:10.1039/C5PY00024F
The amidine- and dimethylaminoethyl-containing block copolymer PADS-b-PDMAEMA was prepared by the combination of reversible addition-fragmentation chain transfer polymerization and click chemistry. Benefitting from its amphiphilic nature, the PADS-b-PDMAEMA copolymer could spontaneously form vesicles in water when the concentration was above the critical aggregation concentration. As the amidine and dimethylamino units in the copolymer are both typical CO2 responsive chemical groups, the PADS-b-PDMAEMA copolymer vesicles presented unique dual CO2 responses. Moreover, the vesicles also showed thermo-responsive behaviours due to the thermal response of the PDMAEMA block. The lower critical solution temperature (LCST) of the copolymer in aqueous solution was 42.8 °C. The size and morphologies of these vesicles can be adjusted by controlling the protonation/deprotonation of amidine and dimethylamino species through bubbling with CO2 or Ar. Alternating treatment with CO2 and Ar could realize a reversible expansion–contraction transformation of these vesicles. Moreover, the reversible vesicles-micelles transition could also be achieved through stimuli of temperature and gas. Due to its CO2- and thermo-responsive properties, the PADS-b-PDMAEMA vesicles were used as a carrier for drug delivery systems. Doxorubicin (DOX), an anticancer drug, was used as a model drug and loaded into the vesicles. The vesicles presented good controlled release behaviour. The release rate and level could be controlled through bubbling with CO2 and by changing the temperature.
Co-reporter:Weizhong Yuan, Lulin Li and Hui Zou
RSC Advances 2015 vol. 5(Issue 98) pp:80264-80268
Publication Date(Web):18 Sep 2015
DOI:10.1039/C5RA16701A
An amphiphilic brush block copolymer P(St-g-PBDEMA)-b-P(MEO2MA-co-OEGMA) was prepared by ATRP, RAFT and click chemistry. The copolymer micelles show temperature and glucose responses. The controlled release of insulin could be achieved by adjusting temperature and glucose concentration.
Co-reporter:Weizhong Yuan, Jin Shen and Hui Zou
RSC Advances 2015 vol. 5(Issue 17) pp:13145-13152
Publication Date(Web):13 Jan 2015
DOI:10.1039/C4RA13118E
An amphiphilic block copolymer poly(ε-caprolactone)-block-poly(N-isopropylacrylamide-co-N,N-dimethylaminoethyl methacrylate) terminated with a pyrene group (Py-PCL-b-P(NIPAM-co-DMAEMA)) was synthesised by the combination of ring-opening polymerisation (ROP), DCC reaction and reversible addition-fragmentation chain transfer polymerisation (RAFT). The micelles self-assembled from the copolymer and showed switchable CO2-temperature dual responses. The copolymerisation incorporating DMAEMA was used as a CO2-responsive trigger into NIPAM, and the lower critical solution temperature (LCST) value could be switched by the gas. The fluorescence intensities and the controlled drug release properties could be adjusted and achieved by altering the temperature of the micelle solution and bubbling CO2/Ar into the micelle solution.
Co-reporter:Weizhong Yuan and Wen Guo
Polymer Chemistry 2014 vol. 5(Issue 14) pp:4259-4267
Publication Date(Web):18 Mar 2014
DOI:10.1039/C3PY01681A
Novel ultraviolet (UV) light-breakable and tunable thermoresponsive amphiphilic block copolymers were synthesized by atom transfer radical polymerization (ATRP). These amphiphilic copolymers can self-assemble into micelles in water. The lower critical solution temperature (LCST) and size of the micelles were adjusted by altering the ratio of 2-(2-methoxyethoxy)ethyl methacrylate (MEO2MA) and oligo(ethylene glycol) methacrylate (OEGMA). Upon UV light irradiation, 2-nitrobenzyl moieties were detached from polymer chains and the micelles were dissociated. When the solutions were heated above LCST, the micelles can be re-self-assembled. Investigation revealed that the Nile red molecules which were encapsulated in micelles can be controllably released through changing temperature and undergoing UV light irradiation of micelle solutions.
Co-reporter:Weizhong Yuan, Tianxiang Shen, Jinju Wang and Hui Zou
Polymer Chemistry 2014 vol. 5(Issue 13) pp:3968-3971
Publication Date(Web):23 Apr 2014
DOI:10.1039/C4PY00463A
An amphiphilic copolymer containing PEO and PAPBA linked by a disulfide bond (PEO–SS–PAPBA) was synthesized by RAFT. The micelles with a PEO shell and a PAPBA core presented glucose, pH and redox triple responses. The controlled release of insulin could be achieved through adding glucose or GSH.
Co-reporter:Weizhong Yuan;Jinju Wang;Lulin Li;Hui Zou;Hua Yuan;Jie Ren
Macromolecular Rapid Communications 2014 Volume 35( Issue 20) pp:1776-1781
Publication Date(Web):
DOI:10.1002/marc.201400308
Co-reporter:Weizhong Yuan, Jin Shen, Lulin Li, Xu Liu, Hui Zou
Carbohydrate Polymers 2014 Volume 113() pp:353-361
Publication Date(Web):26 November 2014
DOI:10.1016/j.carbpol.2014.07.035
•POSS-poly(ɛ-caprolactone)-β-cyclodextrin was synthesized by ROP and click reaction.•The star-shaped copolymer can self-assemble to micelles.•The hybrid micelles can be obtained by complexing with Fe3O4 nanoparticles.•The magnetic hybrid micelles can remove bisphenol A from water.A novel amphiphilic star-shaped inorganic–organic hybrid copolymer polyhedral oligomeric silsesquioxane-poly(ɛ-caprolactone)-β-cyclodextrin (POSS-PCL-β-CD) was synthesized by ring-opening polymerization (ROP) and click chemistry. The amphiphilic copolymer can self-assemble into hybrid micelles with hydrophobic POSS-PCL chain encapsulating Fe3O4 nanoparticles as the core and β-CD as the shell after mixing with Fe3O4 nanoparticles in solvent and dialysis against water. The chemical structure of POSS-PCL-β-CD was characterized by 1H NMR and the morphology of the magnetic hybrid micelles was characterized by TEM and DLS. Due to the host–guest interaction of β-CD with bisphenol A (BPA), POSS-PCL-β-CD/Fe3O4 hybrid micelles present good adsorption capacity in removal of BPA from aqueous solution. Magnetic measurement reveals that POSS-PCL-β-CD/Fe3O4 hybrid micelles still exhibit magnetism for separation by an external magnetic field, indicating that these magnetic hybrid micelles may have potential application in the field of environmental protection.
Co-reporter:Weizhong Yuan and Jinju Wang
RSC Advances 2014 vol. 4(Issue 73) pp:38855-38858
Publication Date(Web):12 Aug 2014
DOI:10.1039/C4RA05096G
P(St-g-QA)-b-P(MEO2MA-co-OEGMA) copolymers were synthesized by RAFT and click chemistry. The micelles self-assembled from the amphiphilic copolymers showed tunable thermoresponse through alteration of the molar ratio of MEO2MA and OEGMA. P(St-g-QA) and P(MEO2MA-co-OEGMA) segments both presented salt response.
Co-reporter:Menghong Jia;Tianbin Ren;An Wang;Jie Ren
Journal of Applied Polymer Science 2014 Volume 131( Issue 7) pp:
Publication Date(Web):
DOI:10.1002/app.40097
Abstract
Star-shaped copolymers poly(ε-caprolactone)-bolck-poly(ε-benzyloxycarbonyl-l-lysine) (SPPCL-b-PZLLs) with porphyrin core were synthesized by a sequential ring-opening polymerization (ROP) of CL and Nε-Benzyloxycarbonyl-l-lysine N-Carboxyanhydride. After the deprotection of benzyloxycarbonyl groups in polylysine blocks, the star-shaped amphiphilic copolymers SPPCL-b-PLLs were obtained. These amphiphilic copolymers can self-assemble into micelles or aggregates in aqueous solution. Investigation shows that the morphology of micelles/aggregates varied according to the change of pH values of media, indicating the pH-responsive property of SPPCL-b-PLL copolymers. Furthermore, associated with conjugated porphyrin cores, the SPPCL-b-PLL copolymers micelles showed a certain degree of Photodynamic Therapy (PDT) effects on tumor cells, suggesting its potential application as carrier for hydrophobic drug with additional therapeutic ability of inherent porphyrin segments. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40097.
Co-reporter:Weizhong Yuan, Jin Shen, Wen Guo
Materials Letters 2014 Volume 134() pp:259-262
Publication Date(Web):1 November 2014
DOI:10.1016/j.matlet.2014.07.108
•P(DMAEMA-co-AzoMA) and β-CD-(PDMAEMA)7 were synthesized by ATRP.•The supra-amphiphiles can self-assemble to spherical nano-micelles.•The micelles present thermoresponse.•The micelles can achieve reversible self-assembly/disassembly.>P(DMAEMA-co-AzoMA)/β-CD-(PDMAEMA)7 supra-amphiphiles were prepared by atom transfer radical polymerization (ATRP) and supramolecular host–guest inclusion complexation between trans-azobenzene and β-CD. The supra-amphiphiles self-assemble to spherical nano-micelles. Owing to the thermoresponse of PDMAEMA segment, the size and the aggregation of the micelles are changed by altering the solution temperature. Upon ultraviolet irradiation, azobenzene moieties undergo trans–cis photoisomerization, and leaves from the cavity of β-CD, which results in the disassembly of supra-amphiphiles. The reversible self-assembly/disassembly behavior of the supra-amphiphiles is achieved by visible light or ultraviolet irradiation. Finally, the supramolecular micelles realize the controlled release of Nile red by adjusting the temperature or light irradiation.
Co-reporter:Hui Zou, Wen Guo and Weizhong Yuan
Journal of Materials Chemistry A 2013 vol. 1(Issue 45) pp:6235-6244
Publication Date(Web):25 Sep 2013
DOI:10.1039/C3TB21181A
An amphiphilic Py-PCL-b-POEGMA copolymer was prepared by the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Based on the host–guest inclusion complexation of α-CD with densely grafted chains of the POEGMA shell in Py-PCL-b-POEGMA micelles, supramolecular micellar hydrogels were obtained by adding α-CD into Py-PCL-b-POEGMA micellar solutions. Resulting from the dissociation of α-CD from the ICs upon heating, the Py-PCL-b-POEGMA IC-based supramolecular hydrogels presented thermo-responsive properties. As they were heated, the IC-based hydrogels underwent gel–sol transformation because of the breakage of the physical cross-links. Benefiting from the fluorescent pyrene group in the Py-PCL-b-POEGMA copolymer, the system showed fluorescent properties. And the fluorescent intensity decreased obviously and regularly during the sol–gel transformation process, which makes it possible to detect the sol–gel transformation through sensing the fluorescent intensity of the system. Due to the biodegradable and biocompatible properties, the IC-based hydrogels were used as carriers for delivery systems. The hydrogels showed good properties for controlled release, and the release rate and level can be controlled by temperature.
Co-reporter:Weizhong Yuan, Wen Guo, Hui Zou and Jie Ren
Polymer Chemistry 2013 vol. 4(Issue 14) pp:3934-3937
Publication Date(Web):14 May 2013
DOI:10.1039/C3PY00478C
A novel amphiphilic block copolymer containing N,N-dimethylaminoethyl and azopyridine groups has been synthesized and self-assembled into micelles with triple tunable responses to temperature, pH and light from the shell to the core of micelles. Moreover, the variations of temperature and pH have obvious influences on the light response.
Co-reporter:Weizhong Yuan, Hui Zou, Wen Guo, Tianxiang Shen and Jie Ren
Polymer Chemistry 2013 vol. 4(Issue 9) pp:2658-2661
Publication Date(Web):27 Feb 2013
DOI:10.1039/C3PY00211J
Novel supramolecular micelles with dual temperature and redox responses were self-assembled from the polyrotaxane of poly(ethylene glycol)–SS–poly(2-(N,N-dimethylamino) ethyl methacrylate) with α-cyclodextrin (PRX–SS–PDMAEMA). The unique micelles present a high drug encapsulation efficiency and multi-controlled drug release behaviour.
Co-reporter:Weizhong Yuan, Jinju Wang, Tianxiang Shen, Jie Ren
Materials Letters 2013 Volume 107() pp:243-246
Publication Date(Web):15 September 2013
DOI:10.1016/j.matlet.2013.06.028
•GO-PDMAEMA was synthesized by ATRP of DMAEMA on the surface of GO.•Quaternized GO-PDMAEMA can be obtained by quaternization of PDMAEMA.•GO-PDMAEMA is a LCST-type thermoresponsive nanocomposite.•Quaternized GO-PDMAEMA is an UCST-type thermoresponsive nanocomposite.•Transition from LCST to UCST: from GO-PDMAEMA to quaternized GO-PDMAEMA.Graphene oxide-poly(2-N,N-dimethylamino)ethyl methacrylate (GO-PDMAEMA) nanocomposite was synthesized via atom transfer radical polymerization (ATRP) and PDMAEMA chains were grafted on the surface of GO. After quaternization, quaternized GO-PDMAEMA nanocomposite was achieved. GO-PDMAEMA shows a lower critical solution temperature (LCST)-type thermoresponsivity, and the dispersion-aggregation behavior was controlled by changing the temperature of the solution. The hydrophilicity of GO-PDMAEMA decreased with increasing temperature. Conversely, the dispersion and hydrophilicity of quaternized GO-PDMAEMA increased with increasing temperature due to the upper critical solution temperature (UCST)-type thermoresponsivity. So the LCST–UCST transition can be accomplished by the transition of PDMAEMA to quaternized PDMAEMA on the surface of GO.
Co-reporter:Weizhong Yuan, Tianxiang Shen, Xu Liu, Jie Ren
Materials Letters 2013 Volume 111() pp:9-12
Publication Date(Web):15 November 2013
DOI:10.1016/j.matlet.2013.08.062
•POSS-(P(MEO2MA-co-OEGMA))8 star-shaped hybrid polymers were synthesized by ATRP.•The inorganic–organic hybrid polymers can self-assemble into micelles.•The hybrid micelles present tunable thermoresponse.A series of novel star-shaped hybrid P(2-(2-methoxyethoxy)ethylmethacrylate)-co-oligo(ethylene glycol) methacrylate (P(MEO2MA-co-OEGMA)) polymers with polyhedral oligomeric silsesquioxane (POSS) core (POSS-(P(MEO2MA-co-OEGMA))8) were synthesized via atom transfer radical polymerization (ATRP). The obtained inorganic–organic hybrid polymers can self-assemble into micelles in aqueous solution owing to the amphiphilic property resulting from the hydrophobic inorganic POSS core and the hydrophilic P(MEO2MA-co-OEGMA) segments. The hybrid polymeric micelles show a significant tunable temperature responsive property which can be adjusted from 29.7 to 39.1 °C through altering the ratio of MEO2MA and OEGMA in P(MEO2MA-co-OEGMA) polymers. These amphiphilic hybrid polymers have potential applications in nano-carrier, nano-reactor, smart materials and biomedical fields..
Co-reporter:Weizhong Yuan;Xu Liu;Hui Zou;Jianbo Li;Hua Yuan;Jie Ren
Macromolecular Chemistry and Physics 2013 Volume 214( Issue 14) pp:1580-1589
Publication Date(Web):
DOI:10.1002/macp.201300201
Co-reporter:Tian-Bin Ren;Chang-Jin Liu;Wei Wu;Kuan Ye ;Wei-Zhong Yuan
Polymer International 2013 Volume 62( Issue 10) pp:1500-1506
Publication Date(Web):
DOI:10.1002/pi.4449
Abstract
Novel, well-defined A4BA4 nonlinear block copolymers [poly(ϵ-caprolactone)]4-block-poly(propylene oxide)-block-[poly(ϵ-caprolactone)]4 (PCL4-b-PPO-b-PCL4) with eight arms were synthesized by ring-opening polymerization. An investigation of melting and crystallization demonstrated that the values of crystallization temperature, melting temperature and degree of crystallinity of PCL4-b-PPO-b-PCL4 were enhanced with an increase of PCL chain length. At the same time, the crystallizability of PCL segments was influenced by the star-shaped structure of the copolymers and the amorphous PPO segments in the copolymers. Furthermore, PCL4-b-PPO-b-PCL4 showed crystalline morphologies that were different from that of linear PCL according to polarized optical microscopy. Moreover, the hydrophilicity of the copolymers could be improved and adjusted by the star-shaped structure and the alteration of the relative content of the PCL and PPO segments in the copolymers.© 2013 Society of Chemical Industry
Co-reporter:Weizhong Yuan, Xu Liu, Hui Zou, Jie Ren
Polymer 2013 Volume 54(Issue 20) pp:5374-5381
Publication Date(Web):6 September 2013
DOI:10.1016/j.polymer.2013.08.008
The star-shaped amphiphilic inorganic–organic hybrid polymer POSS-(PEO)8 prepared via click chemistry can self-assemble into spherical aggregates by directly dissolving the hybrid polymer in water. The regular spherical aggregates were gradually transformed to deformed spherical aggregates, cylinders and sheets through adding different amount of α-CD molecules into the POSS-(PEO)8 spherical aggregates solution due to the host-guest inclusion complexation between POSS-(PEO)8 aggregates and α-CD. Adding different amount of phenol which captured α-CD from PEO chains or increasing the environmental temperature of the self-assemblies solutions which also led to the slipping of α-CD out of PEO can reversibly and dynamically change the sheets to cylinders, deformed spherical aggregates or regular spherical aggregates, showing that the reversibly nanostructural dynamical-change can be induced by altering the environmental conditions of the solutions.
Co-reporter:Weizhong Yuan;Hui Zou;Wen Guo;Tianbin Ren;Jie Ren
Polymer Bulletin 2013 Volume 70( Issue 8) pp:2257-2267
Publication Date(Web):2013 August
DOI:10.1007/s00289-013-0947-7
pH-responsive amphiphilic H-shaped copolymer was prepared by the supramolecular self-assembly between β-cyclodextrin-graft-poly(2-(N,N-diethylamino)ethyl methacrylate) (β-CD-(PDEAEMA)2) and bi-adamantyl terminated poly(ε-caprolactone) (Ad-PCL-Ad). β-CD-(PDEAEMA)2 was synthesized by click reaction of alkynyl-modified β-CD with azide PDEAEMA (PDEAEMA-N3). Ad-PCL-Ad was synthesized by the DCC reaction of bi-hydroxyl terminated PCL (HO-PCL-OH) with adamantaneacetic acid. The supramolecular copolymer can self-assemble into micelles in water at room temperature. The micellization and pH-responsivity of the amphiphilic copolymer solution were investigated by transmittance, dynamic light scattering spectrophotometer, and transmission electron microscopy in water. Investigation shows that the micelles’ sizes can be adjusted through the alteration of the pH values of solutions and the supramolecular copolymer will have the potential applications in biomedical field.
Co-reporter:Weizhong Yuan, Hui Zou, Wen Guo, An Wang and Jie Ren
Journal of Materials Chemistry A 2012 vol. 22(Issue 47) pp:24783-24791
Publication Date(Web):27 Sep 2012
DOI:10.1039/C2JM35297D
The novel and well-defined supramolecular amphiphilic star-branched copolymer poly((caprolactone)-star-(poly(2-N,N-dimethylamino)ethylmethacrylate)7 (PCL-(PDMAEMA)7) with a porphyrin core was prepared via the combination of ring-opening polymerization (ROP), atom transfer radical polymerization (ATRP), and supramolecular host–guest inclusion complexation. After reaction of PDMAEMA with excess 1,3-propane sultone, the quaternized star-PCL-(PDMAEMA)7 was obtained. The amphiphilic star-PCL-(PDMAEMA)7 and quaternized star-PCL-(PDMAEMA)7 can self-assemble into spherical nano-micelles by directly dissolving in water. This thermoresponsive micelles solution shows a transition from a lower critical solution temperature (LCST) of star-PCL-(PDMAEMA)7 to an upper critical solution temperature (UCST) of quaternized star-PCL-(PDMAEMA)7, indicating that the LCST–UCST transition of micellar solutions can be accomplished by the transition of PDMAEMA to quaternized PDMAEMA. Due to the presence of porphyrin molecules in the micelles core, the micelle solutions present obvious fluorescence and the fluorescent intensity can be adjusted by altering the temperatures. For the star-PCL-(PDMAEMA)7 micelle solution, the fluorescent intensity decreases with the increase of temperature, while the fluorescent intensity increases with the increase of temperature for the quaternized star-PCL-(PDMAEMA)7 micelle solution, indicating unique temperature–fluorescence responsive behavior.
Co-reporter:Weizhong Yuan, Jinchun Zhang, Hui Zou, Tianxiang Shen, Jie Ren
Polymer 2012 Volume 53(Issue 4) pp:956-966
Publication Date(Web):17 February 2012
DOI:10.1016/j.polymer.2012.01.003
Novel amphiphilic ethyl cellulose (EC) brush polymers with mono and dual side chains of poly(2-(2-methoxyethoxy)ethyl methacrylate)-co-oligo(ethylene glycol) methacrylate) (P(MEO2MA-co-OEGMA)) and poly(2-(N,N-dimethylamino)ethyl methacrylate) (PDMAEMA) were synthesized by the combination of atom transfer radical polymerization (ATRP) and click chemistry. The molar ratio of P(MEO2MA-co-OEGMA) and PDMAEMA was varied through changing the feed ratio of these polymers and the coupling efficiency of click chemistry is relatively high. The brush polymers can self-assemble into spherical micelles/aggregates. The micelles/aggregates show the tunable temperature-pH responsive properties. The cloud points and the pH-triggered phase transition were influenced by EC chains and the ratio of P(MEO2MA-co-OEGMA) and PDMAEMA side chains. The brush polymers have the great potential applications as biomedical or intelligent materials.
Co-reporter:Weizhong Yuan;Jinchun Zhang;Hui Zou;Jie Ren
Journal of Polymer Science Part A: Polymer Chemistry 2012 Volume 50( Issue 13) pp:2541-2552
Publication Date(Web):
DOI:10.1002/pola.26032
Abstract
Novel and well-defined amphiphilic H-shaped terpolymers poly(L-lactide)-block-(poly(2-(N,N-dimethylamino)ethyl methacrylate) -block-)poly(ε-caprolactone)(-block-poly(2-(N,N-dimethylamino)ethyl methacrylate)) -b-poly(L-lactide) (PLLA-b-(PDMAEMA-b-)PCL(-b-PDMAEMA)-b-PLLA) were synthesized by the combination of ring-opening polymerization, atom transfer radical polymerization, and click chemistry. The H-shaped amphiphilic terpolymers can self-assemble into spherical nano-micelles in water. Because of the dually responsive (temperature and pH) properties of PDMAEMA segments, the hydrodynamic radius of the micelles of the H-shaped terpolymer solution can be adjusted by altering the environmental temperature or pH values. The thermal properties investigation and the crystalline morphology analysis indicate that the branched structure of the H-shaped terpolymers and the presence of amorphous PDMAEMA segments together led to the obvious decrease of PCL segments and the complete destruction of crystallinity of the PLLA segments in the H-shaped terpolymers. In addition, the H-shaped terpolymer film has better hydrophilicity than linear PCL or triblock polymer of PLLA-b-(N3)PCL(N3)-b-PLLA, due to the decrease or destruction of the crystallizability of the PCL or PLLA in the H-shaped terpolymer and the presence of hydrophilic PDMAEMA segments. These unique H-shaped amphiphilic terpolymers composed of biodegradable and biocompatible PCL and PLLA components and intelligent and biocompatible PDMAEMA component will have the potential applications in biomedical fields. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Co-reporter:Weizhong Yuan, Jinchun Zhang, Jingren Wei, Cong Zhang, Jie Ren
European Polymer Journal 2011 Volume 47(Issue 5) pp:949-958
Publication Date(Web):May 2011
DOI:10.1016/j.eurpolymj.2011.01.002
Novel pH-responsive amphiphilic dendritic star-block poly(l-lactide)-b-poly(2-(N, N-diethylamino)ethyl methacrylate)-b-poly(ethylene oxide) (DPLLA-b-PDEAEMA-b-PEO) terpolymers were synthesized by the combination of ring-opening polymerization (ROP), atom transfer radical polymerization (ATRP), and click chemistry. DPLLAOH was synthesized by ROP of l-lactide (LLA) and then reacted with propargyl 3-carboxylic-propanoate to obtain alkynyl-DPLLA. PEO-b-PDEAEMA-Br was prepared by ATRP of DEAEMA and then reacted with NaN3 to obtain PEO-b-PDEAEMA-N3. DPLLA-b-PDEAEMA-b-PEO was easily prepared by click chemistry of alkynyl-DPLLA and PEO-b-PDEAEMA-N3. DPLLA-b-PDEAEMA-b-PEO can assemble into micelles in water with PLLA segments as core and PEO segments as corona. The hydrophilicity/hydrophobicity of PDEAEMA can be adjusted with the alteration of pH values. Therefore, PDEAEMA segments form core or corona of micelles at pH ⩾ 7 or pH < 7. Due to the pH-responsive property of PDEAEMA and unique structure of terpolymer, the size and conformation of the micelles can be changed to some extent by altering the pH values of solutions.
Co-reporter:Weizhong Yuan, Zhengda Zhao, Shuying Gu, Tianbin Ren, Jie Ren
Materials Letters 2011 Volume 65(Issue 4) pp:793-796
Publication Date(Web):28 February 2011
DOI:10.1016/j.matlet.2010.11.043
Amphiphilic chitosan-graft-poly(2-(N,N-diethylamino)ethyl methacrylate)-block-poly(ethylene oxide) (CS-g-(PDEAEMA-b-PEO)) copolymer was synthesized by the combination of atom transfer radical polymerization (ATRP) and click chemistry. The copolymer was characterized by 1H NMR spectrum. The self-assembly and pH-responsive properties of CS copolymer were investigated by TEM, DLS, and transmittance in water. The micelle sizes can be adjusted through the alteration of the pH values of solutions. The presence of PEO segments can improve the hydrophilicity of the copolymer and avoid the excessive aggregation of the micelles. CS-g-(PDEAEMA-b-PEO) copolymer has both the unique properties of PDEAEMA-b-PEO and chitosan, and will have the potential applications in biomedical field.
Co-reporter:Weizhong Yuan;Zhengda Zhao;Jinying Yuan;Shuying Gu;Fengbo Zhang;Xuming Xie;Jie Ren
Polymer International 2011 Volume 60( Issue 2) pp:194-201
Publication Date(Web):
DOI:10.1002/pi.2926
Abstract
Novel pH- and temperature-responsive chitosan-graft-poly[2-(N,N-dimethylamino)ethyl methacrylate] (chitosan-g-PDMAEMA) copolymers were successfully synthesized by homogeneous atom transfer radical polymerization (ATRP) under mild conditions. Chitosan macroinitiator was prepared by phthaloylation of amino groups of chitosan and subsequent acylation of hydroxyl groups of chitosan with 2-bromoisobutyryl bromide. The copolymers were obtained by ATRP of 2-(N,N-dimethylamino)ethyl methacrylate and they can self-assemble into stable micelles in water. Hybrid micelles with a PDMAEMA corona incorporating gold nanoparticles (Au NPs) were prepared in situ via the reduction of HAuCl4 with NaBH4. The pH and temperature responses of the copolymer micelles and hybrid micelles were characterized using UV-visible spectroscopy and dynamic laser light scattering. The morphology of the micelles was observed using transmission electron microscopy and atomic force microscopy. The PDMAEMA corona of the micelles acts as the ‘nanoreactor’ and the ‘anchor’ for the in situ formation and stabilization of Au NPs. Therefore, the spatial distribution of Au NPs within the micelles can be tuned by varying the temperature and pH value. Copyright © 2010 Society of Chemical Industry
Co-reporter:Weizhong Yuan, Xiaofei Li, Shuying Gu, Amin Cao, Jie Ren
Polymer 2011 Volume 52(Issue 3) pp:658-666
Publication Date(Web):3 February 2011
DOI:10.1016/j.polymer.2010.12.052
Novel amphiphilic chitosan-g-poly(ε-caprolactone)-(g-poly(2-(2-methoxyethoxy)ethyl methacrylate)-co-oligo(ethylene glycol) methacrylate) (CS-g-PCL(-g-P(MEO2MA-co-OEGMA))) copolymers with double side chains of PCL and P(MEO2MA-co-OEGMA) were synthesized via combination of ring-opening polymerization (ROP), atom transfer radical polymerization (ATRP) and click chemistry. The molar ratio of PCL and P(MEO2MA-co-OEGMA) was varied through variation of the feed ratio and the coupling efficiency of click chemistry is comparatively high. The graft copolymers can assemble into spherical micelles. The micelles show thermosensitive properties and the lower critical solution temperatures (LCSTs) were influenced by CS chains and the ratio of PCL and P(MEO2MA-co-OEGMA) side chains. Moreover, the micelles can reversibly swell and shrink in response to the change of temperatures. Furthermore, the micelles present obvious fluorescence and the fluorescent intensity can be adjusted by altering the temperatures. The investigation of doxorubicin release from the micelles indicated that the release rate of the drug could be effectively controlled by altering the temperatures.
Co-reporter:Weizhong Yuan;Jinchun Zhang;Jingren Wei;Hua Yuan;Jie Ren
Journal of Polymer Science Part A: Polymer Chemistry 2011 Volume 49( Issue 18) pp:4071-4080
Publication Date(Web):
DOI:10.1002/pola.24850
Abstract
Novel and well-defined amphiphilic dendrimer-star copolymer poly(ε-caprolactone)-block-(poly(2-(2-methoxyethoxy)ethylmethacrylate-co-oligo(ethylene glycol) methacrylate))2 with Y-shaped arms were synthesized by the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The investigation of thermal properties and the analysis of crystalline morphology indicate that the high-branched structure of dendrimer-star copolymers with Y-shaped arms and the presence of amorphous P(MEO2MA-co-OEGMA) segments together led to the complete destruction of crystallinity of the PCL segments in the dendrimer-star copolymer. In addition, the hydrophilicity–hydrophobicity transition of the dendrimer-star copolymer film can be achieved by altering the external temperatures. The amphiphilic copolymers can self-assemble into spherical nanomicelles in water. Because the lower critical solution temperature of the copolymers can be adjusted by varying the ratio of MEO2MA and OEGMA, the tunable thermosensitive properties can be observed by transmittance, dynamic laser light scattering, and transmission electron microscopy (TEM). The release rate of model drug chlorambucil from the micelles can be effectively controlled by changing the external temperatures, which indicates that these unique high-branched amphiphilic copolymers have the potential applications in biomedical field. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Co-reporter:Tianbin Ren;An Wang;Lan Li;Yue Feng
Journal of Polymer Science Part A: Polymer Chemistry 2011 Volume 49( Issue 10) pp:2303-2313
Publication Date(Web):
DOI:10.1002/pola.24665
Abstract
Star-shaped amphiphilic poly(ε-caprolactone)-block-poly(oligo(ethylene glycol) methyl ether methacrylate) with porphyrin core (SPPCL-b-POEGMA) was synthesized by combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Star-shaped PCL with porphyrin core (SPPCL) was prepared by bulk polymerization of ε-caprolactone (CL) with tetrahydroxyethyl-terminated porphyrin initiator and tin 2-ethylexanote (Sn(Oct)2) catalyst. SPPCL was converted into SPPCLBr macroinitiator with 2-bromoisobutyryl bromide. Star-shaped SPPCL-b-POEGMA was obtained via ATRP of oligo(ethylene glycol) methyl ether methacrylate (OEGMA). SPPCL-b-POEGMA can easily self-assemble into micelles in aqueous solution via dialysis method. The formation of micellar aggregates were confirmed by critical micelle formation concentration, dynamic light scattering, and transmission electron microscopy. The micelles also exhibit property of temperature-induced drug release and the lower critical solution temperature (LCST) was 60.6 °C. Furthermore, SPPCL-b-POEGMA micelles can reversibly swell and shrink in response to external temperature. In addition, SPPCL-b-POEGMA can present obvious fluorescence. Finally, the controlled drug release of copolymer micelles can be achieved by the change of temperatures. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Co-reporter:Xiaofei Li, Weizhong Yuan, Shuying Gu, Jie Ren
Materials Letters 2010 Volume 64(Issue 24) pp:2663-2666
Publication Date(Web):31 December 2010
DOI:10.1016/j.matlet.2010.08.077
Amphiphilic chitosan-graft-P(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol) methacrylate) (CS-g-P(MEO2MA-co-OEGMA)) copolymers were synthesized by the “graft onto” method via click chemistry. The graft copolymers were characterized by 1H NMR and ATR FT-IR measurements. The self-assembly behavior and tunable thermosensitive properties of CS copolymers in water were investigated by TEM, DLS, and transmittance. The lower critical solution temperature (LCST) values of CS copolymer micelle solutions were tuned by altering the molar ratio of MEO2MA and OEGMA in copolymers. Furthermore, the copolymer micelles can reversibly swell and shrink in response to external temperature. The obtained tunable thermosensitive amphiphilic CS copolymers have both the unique properties of P(MEO2MA-co-OEGMA) and chitosan, and will have the potential applications in the biomedical field.
Co-reporter:Weizhong Yuan;Zhengda Zhao;Shuying Gu ;Jie Ren
Journal of Polymer Science Part A: Polymer Chemistry 2010 Volume 48( Issue 15) pp:3476-3486
Publication Date(Web):
DOI:10.1002/pola.24136
Abstract
Novel amphiphilic chitosan copolymers with mixed side chains of poly(ε-caprolactone) and poly(ethylene oxide) (CS-g-PCL/PEO) were successfully synthesized by “graft to” approach via click chemistry. The melting and crystallization behaviors and crystalline morphology of CS-g-PCL/PEO copolymers can be adjusted by the alteration of the feed ratio of PCL and PEO segments. CS-g-PCL/PEO copolymers revealed crystalline morphology different from that of linear alkynyl PCL and alkynyl PEO due to the influence of brush structure of copolymers and the mutual influence of PCL and PEO segments. The hydrophilicity of the CS copolymers can be improved and adjusted by the alteration of the composition of PCL and PEO segments. Moreover, the CS copolymers can self-assemble into spherical micelles in aqueous solution. Investigation shows that the size of the CS copolymer micelles increased with the increase of the content of hydrophobic PCL segments in copolymers, which indicated that the micellar behavior of the copolymers can be controlled by the adjustment of the ratio of PCL and PEO segments in copolymer. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3476–3486, 2010
Co-reporter:Weizhong Yuan, Hui Zou, Wen Guo, An Wang and Jie Ren
Journal of Materials Chemistry A 2012 - vol. 22(Issue 47) pp:NaN24791-24791
Publication Date(Web):2012/09/27
DOI:10.1039/C2JM35297D
The novel and well-defined supramolecular amphiphilic star-branched copolymer poly((caprolactone)-star-(poly(2-N,N-dimethylamino)ethylmethacrylate)7 (PCL-(PDMAEMA)7) with a porphyrin core was prepared via the combination of ring-opening polymerization (ROP), atom transfer radical polymerization (ATRP), and supramolecular host–guest inclusion complexation. After reaction of PDMAEMA with excess 1,3-propane sultone, the quaternized star-PCL-(PDMAEMA)7 was obtained. The amphiphilic star-PCL-(PDMAEMA)7 and quaternized star-PCL-(PDMAEMA)7 can self-assemble into spherical nano-micelles by directly dissolving in water. This thermoresponsive micelles solution shows a transition from a lower critical solution temperature (LCST) of star-PCL-(PDMAEMA)7 to an upper critical solution temperature (UCST) of quaternized star-PCL-(PDMAEMA)7, indicating that the LCST–UCST transition of micellar solutions can be accomplished by the transition of PDMAEMA to quaternized PDMAEMA. Due to the presence of porphyrin molecules in the micelles core, the micelle solutions present obvious fluorescence and the fluorescent intensity can be adjusted by altering the temperatures. For the star-PCL-(PDMAEMA)7 micelle solution, the fluorescent intensity decreases with the increase of temperature, while the fluorescent intensity increases with the increase of temperature for the quaternized star-PCL-(PDMAEMA)7 micelle solution, indicating unique temperature–fluorescence responsive behavior.
Co-reporter:Hui Zou and Weizhong Yuan
Journal of Materials Chemistry A 2015 - vol. 3(Issue 2) pp:NaN269-269
Publication Date(Web):2014/11/03
DOI:10.1039/C4TB01518E
An amphiphilic PCL-SS-PDMAEMA copolymer was synthesized by the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) using a new disulfide functionalized double-head initiator with both terminal hydroxyl and bromine groups. Based on the self-assembly of the PCL-SS-PDMAEMA copolymer with oleic acid modified Fe3O4 nanoparticles in aqueous solutions, magnetic PCL-SS-PDMAEMA/Fe3O4 complex micelles with a saturation magnetization of 10.20 emu g−1 were prepared. The investigation of magnetothermal properties of the magnetic complex micelles showed that the temperature of the magnetic micellar systems increased in the alternating magnetic field (AMF) and the increasing rate and steady-state temperature could be adjusted through altering the magnetic flux density. Benefitting from the thermal response of PDMAEMA and redox response of the disulfide bond, the magnetic complex micelles presented obvious temperature- and redox-responsive properties. The Rh of the magnetic complex micelles would decrease when the micellar solutions were heated. And when DTT was added into the magnetic micellar systems, the distributions of Rh broadened with the emergence of aggregates. Due to the magnetic, magnetothermal, temperature- and redox-responsive properties, the magnetic complex micelles were used as a carrier for drug delivery systems. Doxorubicin (DOX), an anticancer drug, was used as a model drug and loaded into the magnetic complex micelles. The magnetic complex micelles presented good properties for controlled release. The release rate and level could be controlled by adding an external AMF and altering the DTT concentration.
Co-reporter:Hui Zou, Wen Guo and Weizhong Yuan
Journal of Materials Chemistry A 2013 - vol. 1(Issue 45) pp:NaN6244-6244
Publication Date(Web):2013/09/25
DOI:10.1039/C3TB21181A
An amphiphilic Py-PCL-b-POEGMA copolymer was prepared by the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Based on the host–guest inclusion complexation of α-CD with densely grafted chains of the POEGMA shell in Py-PCL-b-POEGMA micelles, supramolecular micellar hydrogels were obtained by adding α-CD into Py-PCL-b-POEGMA micellar solutions. Resulting from the dissociation of α-CD from the ICs upon heating, the Py-PCL-b-POEGMA IC-based supramolecular hydrogels presented thermo-responsive properties. As they were heated, the IC-based hydrogels underwent gel–sol transformation because of the breakage of the physical cross-links. Benefiting from the fluorescent pyrene group in the Py-PCL-b-POEGMA copolymer, the system showed fluorescent properties. And the fluorescent intensity decreased obviously and regularly during the sol–gel transformation process, which makes it possible to detect the sol–gel transformation through sensing the fluorescent intensity of the system. Due to the biodegradable and biocompatible properties, the IC-based hydrogels were used as carriers for delivery systems. The hydrogels showed good properties for controlled release, and the release rate and level can be controlled by temperature.
Co-reporter:Hui Zou, Weizhong Yuan, Yeqiang Lu and Shanfeng Wang
Chemical Communications 2017 - vol. 53(Issue 16) pp:NaN2466-2466
Publication Date(Web):2017/02/03
DOI:10.1039/C6CC09959A
UV light- and thermo-responsive supramolecular aggregates with tunable morphologies were obtained through the inclusion complexation between a β-CD containing dendritic host polymer and an azobenzene containing linear guest polymer. Morphologies of the aggregates could be adjusted by changing the molar ratio of host/guest polymers in the supramolecular polymers.
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