ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Jiaqing He,Qiang Zhou,Zhiqing Ge,Shunfeng Jiang,Jiahe Li,Wei Feng,Haiyang Yang
Temperature-responsive hydrogels including lower critical solution temperature (LCST)- and upper critical solution temperature (UCST)-type hydrogels are attractive in various fields. However, the swift switch between LCST and UCST stimuli-responsive behaviors remains intriguing and challenging. Here is reported a kind of hydrogel with pH-gated LCST and UCST response behaviors. This is achieved using the hydrogen bonding between carboxylic acid groups of poly(acrylic acid- co -acrylamide) and hydroxyl groups of hydroxypropyl cellulose (HPC). The poly(acrylic acid- co -acrylamide)-HPC (PACA-HPC) hydrogels exhibit pH-gated reversible LCST-UCST phase transition behavior. When the transparent PACA-HPC hydrogel is placed in an acid bath, the COO − groups get protonated, rapidly forming hydrogen bonds with HPC to render a light-scattering state making the hydrogel opaque. Furthermore, the opaque hydrogel exhibits UCST phase transition behavior at 20–45 °C. When the opaque PCAC-HPC hydrogel is placed in an alkaline environment, hydrogen-bonded complexes gradually dissociate as the COOH groups are deprotonated to form a homogeneous transparent state. The transparent hydrogel exhibits LCST phase transition behavior at 20–45° C. Therefore, is shown the hydrogen bonding strategy to fabricate hydrogels with tunable LCST and UCST responses. With this pH-gated hydrogel with switchable LCST/UCST responsive behaviors, are demonstrated its applications in smart windows and information encryption.
研究领域:
材料科学
·
化学工程
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Ruixia Liu,Tingting Ding,Pingping Deng,Xiaofan Yan,Fuquan Xiong,Jienan Chen,Zhiping Wu
To expand the field of high-value utilization of lignin. The degraded deep eutectic solvent lignin-grafted poly (N-Vinyl caprolactam) (DES-lignin-g-PNVCL) was synthesized by modified DES-lignin and NVCL via the combination of activators regenerated by electron transfer-atom transfer radical polymerization (ARGET-ATRP). Fourier transform infrared spectroscopy (FT-IR), 1 H NMR, X-ray electron spectroscopy (XPS), dynamic light scattering (DLS), differential scanning calorimeter (DSC) were used to characterize the structure and performance of DES-lignin-g-PNVCL. The results indicated that the PNVCL and DES-lignin-g-PNVCL were successfully prepared by ARGET-ATRP. The lowest critical solution temperature (LCST) of PNVCL was 35.75 °C. Due to different strength of hydrogen bond , different energies were required, so the LCST of the polymer can be regulated. When the molar ratio of phenolic hydroxyl group in degraded DES-lignin to 2-bromoisobutyryl bromide (BiBB) was increased from 1:1 to 1:7, the grafting rate of DES-lignin-Br was increased from 32.87% to 60.84%, and the LCST of DES-lignin-g-PNVCL was decreased from 47.98 °C to 27.88 °C. The LCST of DES-lignin-g-PNVCL was increased from 30.98 °C to 44.64 °C when the addition amount of DES-lignin-Br was increased from 20 mg to 200 mg. The LCST of DES-lignin-g-PNVCL was increased from 27.20 °C to 39.86 °C when the ratio of DMF/water was increased from 1:4 to 4:1. The LCST of DES-lignin-g-PNVCL was decreased from 52.10 °C to 31.02 °C when the concentration of DES-lignin-g-PNVCL was increased from 0.5 mg/mL to 2.5 mg/mL. The equation represented the relationship between LCST and influencing factors was obtained, the good predictability provided a tactics for preparing desired LCST thermo-responsible polymer.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOMACROMOLECULES
·
2018
·
IF 5.738
Chao Xing,Zhekun Shi,Jiliang Tian,Jing Sun,Zhibo Li
Stimuli-responsive polymers have received increasing interest for a variety of applications. Here, we report a series of unique charge-determined thermoresponsive polypeptoids synthesized by a combination of ring-opening polymerization and click chemistry. The LCST-type and UCST-type behavior is mainly dominated by the charge state on the side chain. Further, the phase transition temperature highly depends on the degree of polymerization, the side-chain architecture, the pH value, and so on. The obtained polypeptoid solutions exhibit good stability against temperature and salt concentration. To our knowledge, this report presents the first charge-determined LCST/UCST-type polymer from identical homopolymer backbone that displays a wide range of tunable cloudy points in aqueous media. We propose the hydrogen-bonding interaction plays a critical part on the solution behavior. These features make polypeptoids ideal candidates for highly designable stimuli-responsive polymeric materials.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Hongwei Lu,Danling Wang,Daye Huang,Luyao Feng,Huapeng Zhang,Peng Zhu
PNIPAM as a stimuli-responsive polymer has generated extreme interests due to its versatile applications. However, there is no research report on whether PNIPAM micro/nano-particles can be extracted from its suspension after phase separation. In the present work, LCST-type phase separation in self-synthesized PNIPAM/water system was investigated in depth by dividing the DLS testing process into four stages. In addition to quenching duration, temperature rise process, quenching temperature and PNIPAM concentration all have a great influence on particle size of the suspension. Meanwhile, the steady-state rheology and dynamic viscoelasticity results show that PNIPAM micro/nano-particles in the suspension are “soft” that can deform. Finally, FE-SEM was used to observe the morphology of dehydrated PNIPAM extracted by sessile droplet evaporation under different conditions. The results indicate that these “soft” particles are easier to fuse together, do not have sufficient mechanical strength to maintain their spherical morphology after dehydration. But the above fusion can be suppressed by adjusting evaporation conditions to acquire smaller PNIPAM particles which have sufficient mechanical properties to keep their basic particle morphology . Further, by changing evaporation pressure to positive or negative pressure, dehydrated PNIPAM micro/nano-particles with excellent uniformity and separation can be obtained. This work will provide guidance for extracting micro/nano-particles from polymer/diluent systems with LCST .
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2020
·
IF 0
Yongliang Ding,Youxian Yan,Qiang Peng,Baoxia Wang,Yuxian Xing,Zan Hua,Zhongkai Wang
It has been a significant challenge to prepare multiple-response hydrogels with both lower critical solution temperature (LCST) and upper critical solution temperature (UCST). This work reports the synthesis of methyl cellulose-graft-polyacrylamide (MC-g-PAM) hydrogels by ceric ion initiated graft polymerization. Mechanically strong MC-g-PAM hydrogels combine LCST and UCST in one system (LCST > UCST), which provides a transparent “temperature window”. The range of this temperature window can be tuned by changing cellulose contents or adding sodium chloride. In addition, the transmittance of MC-g-PAM hydrogels can be precisely controlled via application of varied DC voltage. These desirable properties make the MC-g-PAM hydrogels as smart materials.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
Polymer Chemistry
·
2017
·Vol. 8
·期 37
·5749-5760
·
IF 5.375
Hongcan Zhang,Jian Zhang,Wenxue Dai,Youliang Zhao
The simple and straightforward construction of multi-responsive systems with tunable LCST and UCST dual phase transitions is a great challenge. This study affords an efficient route to tune cloud points via control over the chemical composition of hydroxyl and diethylamino bearing poly(amido thioether)s which were prepared by one-pot thiol–amine–acrylate polyaddition. Owing to the balance of inter/intrachain interactions, various copolymers could exhibit LCST (fOH < 0.84), LCST–UCST (fOH = 0.84–0.89) and UCST (fOH > 0.89) behaviors relying on the hydroxyl fraction in comonomer units. Meanwhile, the thermoresponsive behaviors of copolymer solutions could be efficiently tuned via switching the solvent and solution pH, applying CO2/N2 bubbling, and oxidation. The success of this study further paves the way for the robust synthesis and practical applications of smart polymers with double thermoresponsivity.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 89
·86012-86018
·
IF 3.289
Mengmeng Li,Xiaoyan Song,Tingbin Zhang,Lintao Zeng,Jinfeng Xing
In this study, an organic–inorganic temperature-sensitive polymer encapsulating tetraphenylethene (TPE) was designed. Its fluorescence intensity is sensitive to temperature changes and reaches a maximum at normal cell temperature. Firstly, the organic–inorganic hybrid polymer, polyhedral oligomeric silsesquioxane-based-poly(N-isopropylacrylamide) (POSS-b-PNIPAM) with a particular LCST of 37.5 °C, was synthesized by atom transfer radical polymerization. POSS-b-PNIPAM self-assembled in aqueous solutions to form stable micelles and then TPE was assembled into the micelles in water. The fluorescence intensity of TPE encapsulated in POSS-b-PNIPAM can be tuned by changing the temperature. The fluorescence intensity of TPE encapsulated in POSS-b-PNIPAM reached a maximum at 37 °C, which is much higher than the TPE fluorescence intensity at the same temperature. TPE encapsulated in POSS-b-PNIPAM still showed high fluorescence intensity after entering HeLa cells at 37 °C.
研究领域:
材料科学
·
高分子化学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Soft Matter
·
2016
·Vol. 12
·期 8
·2473-2480
·
IF 3.798
Lei Hou,Qijing Chen,Zesheng An,Peiyi Wu
The lower critical solution temperature (LCST) transition in water and the upper critical solution temperature (UCST) transition in ethanol of poly(oligo(ethylene glycol) acrylate) (POEGA)-based core cross-linked star (CCS) polymers have been investigated and compared by employing turbidity, dynamic light scattering (DLS), 1H NMR and FTIR measurements. Macroscopic phase transitions in water and in ethanol were observed to occur when passing through the transition temperature, as revealed by DLS and turbidity measurements. Analysis by IR indicated that the interactions between the polymer chains and solvent molecules in water are stronger than those in ethanol such that the CCS polymer arm chains in water adopt more extended conformations. Moreover, hydrophobic interaction among the aliphatic groups plays a predominant role in the LCST-type transition in water whereas weak solvation of the polymer chains results in the UCST-type transition in ethanol. Additionally, the LCST-type transition in water was observed to be much more abrupt and complete than the UCST-type transition in ethanol, as suggested by 1H NMR and IR at the molecular level. Finally, an abnormal “forced hydration” phenomenon was observed during the LCST transition upon heating. This study provides a detailed understanding of the subtle distinctions between the thermal transitions of CCS polymers in two commonly used solvents, which may be useful to guide future materials design for a wide range of applications.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Yu-Lin Hong,Jian Sun,Hong-Wei Yang,Chang Wang,Yun Liu,Zhi-Wei Tan,Cheng-Mei Liu
Nitrile-rich polymers have found applications in carbon fibre, functional materials and rubber industry, though nitrile-rich polyelectrolytes have seldom been reported before. Here we present a nitrile-rich reactive phosphonium-based polyelectrolyte (PVBzTCPC) synthesized by the RAFT polymerization of 4-vinylbenzyl-tris(2-cyanoethyl)phosphonium chloride (VBzTCPC), a CN-rich phosphonium monomer prepared from tris(2-cyanoethyl)phosphine (TCP) and 4-vinylbenzyl chloride. The RAFT polymerization behaviour of the monomer was studied and it was found that the polymerization of monomer proceeded in a controlled/living manner. PVBzTCPC underwent the Wittig reaction and vinyl groups were introduced into the polymer chain as polymerizable pendant groups. Post-polymerization modifications of PVBzTCPC through the nitrile group proceeded successfully and the modified polymers were also phosphonium-based polyelectrolytes. PVBzTCPC showed a high tendency to form an undissolved polyelectrolyte complex with sodium perfluorooctanoate in aqueous solution, which provided a possible way of removing this persistent organic pollutant from water. The DMF solution of CN-rich PVBzTCPC showed LCST-type (lower critical solution temperature) phase transition without adding any foreign salts over 100 °C, and a possible mechanism of LCST transition was proposed.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 7
·2921
·
IF 4.6
Yunyun Tu,Dandan Fang,Wanli Zhan,Zengming Wei,Liming Yang,Penghui Shao,Xubiao Luo,Guang Yang
Thermal-responsive block copolymers are a special type of macromolecule that exhibit a wide range of applications in various fields. In this contribution, we report a new type of polyacrylamide-based block copolymer bearing pyridine groups of polyethylene glycol-block-poly(N-(2-methylpyridine)-acrylamide; Px) that display distinct salt-induced lower critical solution temperature (LCST) behavior. Unexpectedly, the phase-transition mechanism of the salt-induced LCST behavior of Px block copolymers is different from that of the reported LCST-featured analogues. Moreover, their thermo-responsive behavior can be significantly regulated by several parameters such as salt species and concentration, urea, polymerization degree, polymer concentration and pH values. This unique thermal behavior of pyridine-containing block copolymers provides a new avenue for the fabrication of smart polymer materials with potential applications in biomedicine.Keywords:thermo-responsive;block-copolymer;LCST;self-assembly;nanomaterial
研究领域:
高分子化学
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 10
·1922-1930
·
IF 5.687
Yanzhi Xu,Mengxiang Zhu,Minjie Li,Ying Ling,Haoyu Tang
Water-soluble thermoresponsive poly(γ-4-methylbenzyl-L-glutamate) bearing Y-shaped (i.e., oligo-ethylene-glycol and alkyl groups, such as 1-butyl, 1-hexyl, or 1-dodecyl) and triazolium tetrafluoroborate side-chains (PMBLG-OEG7/Cm-BF4, m = 4, 6, and 12) have been prepared by nucleophilic substitution of poly(γ-4-methylbenzyl-L-glutamate)-oligo-ethylene-glycol conjugates (PMBLG-OEG7) and various 1-alkyl bromide and ion-exchange reactions of triazolium bromide and NaBF4. Poly(γ-4-chloromethylbenzyl-L-glutamate) (PCMBLG) was derivatized into poly(γ-4-azidomethylbenzyl-L-glutamate) (PAMBLG), followed by reaction with propargyl functionalized polyethylene glycol monomethylether 350 (Pr-OEG7) via a copper-mediated 1,3-dipolar cycloaddition to yield PMBLG-OEG7. PMBLG-OEG7/Cm-BF4, m = 4, 6, and 12) adopted an α-helical conformation and showed lower critical solution temperature (LCST)-type phase behaviors in aqueous solutions. The cloud point temperature (Tcp) was significantly decreased with an increase in polymer concentration and salt (e.g., NaBF4) concentration. Elongating the alkyl chain length can further decrease the Tcp.
研究领域:
高分子化学
·
生物材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 17
·9626-9634
·
IF 11.9
Hao Wu,Mi Wang,Wanbao Wu,De Bai,Yihong Liang,Shunyou Hu,Wen Yu,Peng He,Jiaheng Zhang
Multi-stimuli-responsive devices have attracted much attention in the field of smart windows due to their rich color-adjustable effect and high energy efficiency. However, most multi-stimuli-responsive color-adjustable devices have insufficient stability and complex preparation processes, which impede their industrialization. In this work, thermo- and electro-dual-responsive devices were fabricated by preparing thermochromic ion gel electrolytes and combining them with electrochromic films. Locating thermochromic and electrochromic materials in different functional layers reduces their mutual influence and prevents a decline in their single performances. The thermochromic ion gel electrolytes with a lower critical solution temperature (LCST) phenomenon were obtained from a simple UV-curing method with polyurethane acrylate oligomers and ionic liquids. Compared with traditional LCST hydrogels, the ion gels undergo phase transitions without a volume change, exhibit better thermal and ambient stability, and possess a wide electrochemical window. They can be widely used as electrolytes for various electrochromic materials, resulting in color-changing performance and cycling stability comparable to those of organic solution and ionic liquid electrolytes. The ion gels' LCST effect and the electrochromic layers' color-changing characteristics endow the devices with a dual-responsive feature and improved optical modulation ability. This gives the devices great application potential in smart windows and indoor decorations.
研究领域:
材料科学
·
电化学
·
光学
·
智能材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）