POLYMER DEGRADATION AND STABILITY
·
2018
·
IF 3.193
Ke Huang,Hongyan Wu,Fan Jiang,Guozhu Shen,Lu Wang
Smart near-infrared (NIR) light-responsive poly N-isopropylacrylamide (PNIPAM) nanocomposite hydrogels were prepared by incorporating sparse chemical cross-linking of small molecules. The thermo-sensitive, NIR light-responsive, toughness and strength of the pure PNIPAM, PNIPAM-Graphene oxide(GO) and PNIPAM-GO-Zirconia(ZrO 2 ) hydrogels were invesitgated. The introduction of GO induced PNIPAM the transformation from the thermosensitive to NIR light-responsive, and the oxidized groups of GO nanosheets could physically cross-link the PNIPAM chains to increase the toughness of the hydrogel networks. The loading capability and penetration resistance of PNIPAM-GO-ZrO 2 composite hydrogel was obviously improved due to that the ZrO 2 powder stabilize the hydrogel networks and strengthen the hydrogen bond interaction with the amide groups of PNIPAM chains compared with that of the pure PNIPAM and PNIPAM-GO, respectively.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 47
·6903-6913
·
IF 5.582
Si Wu,Lei Lei,Yuzheng Xia,Susan Oliver,Xiaonong Chen,Cyrille Boyer,Zhiyong Nie,Shuxian Shi
Multifunctional hybrid particles have been attracting tremendous interest over decades. Herein we demonstrated the functionality of poly(N-isopropylacrylamide) immobilized gold nanoparticles (PNIPAMs-AuNP) as both colorimetric temperature-sensors and reusable temperature-switchable catalysts. The hybrid nanoparticles composed of a gold core (diameter = 14.8 ± 0.2 nm) and a PNIPAM shell (thickness = 2.6 ± 0.2 nm) exhibit reversible color changes and size adjustment in aqueous dispersion upon salt and environment temperature variation. Visual observation or colorimetric monitoring of the PNIPAMs-AuNP dispersion through a UV-vis spectrometer, we were able to detect and calibrate the changes in color between red–purple–red as the environmental temperature changes. The synergetic effect of different types of salt has been systematically investigated. It is observed that the sensitivity of the colorimetric temperature-sensor could be significantly improved by adding salts (NaCl < KCl < MgCl2) or controlling salt concentrations. Moreover, the temperature-switchable PNIPAMs-AuNP hybrid nanoparticles were applied to catalyze the reduction reaction of 4-nitrophenol to 4-aminophenol. The reduction process can be sped-up or slowed-down by controlling the system temperature, which switches the catalytic AuNPs surface on and off as the reversible PNIPAM chains collapse (hydrodynamic size = 41 ± 1 nm) and expand (49 ± 1 nm). Moreover, the switchable catalysts can be recycled through centrifugation and reused. The polymer-engineered core–shell PNIPAMs-AuNP hybrid nanoparticles are promising to enrich the development of temperature-responsive systems such as ambient temperature alarms and smart catalysts.
研究领域:
材料科学
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化学工程
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2013
·Vol. 51
·期 10
·2142-2149
·
IF 3.543
Chen He,Ban-Kun Jin,Wei-Dong He,Xue-Song Ge,Jing Tao,Jing Yang,Sheng-Qi Chen
Long-subchain hyperbranched polystyrene (lsc-hp PSt) with uniform subchain length was obtained through copper-catalyzed azide-alkyne cycloaddition click chemistry from seesaw macromonomer of PSt having one alkynyl group anchored at the chain centre and two azido group attached to both chain ends [alkynyl-(PSt-N 3 ) 2 ]. After precipitation fraction, different portions of lsc-hp PSt having narrow overall molecular weight distribution were obtained for further grafting with alkynyl-capped poly( N -isopropylacrylamide) (alkynyl-PNIPAM), which was obtained via single-electron transfer living radical polymerization of NIPAM with propargyl 2-bromoisobutyrate as the initiator and grafted onto the peripheral azido groups of lsc-hp PSt via click chemistry. Thus, amphiphilic lsc-hp PSt grafted with PNIPAM chains (lsc-hp PSt- g -PNIPAM) was obtained and would have star-like conformation in tetrahydrofuran (THF). By replacing THF with water, lsc-hp PSt- g -PNIPAM was dissolved at molecular level in aqueous solution due to the hydrophilicity of PNIPAM and exhibited thermal induced shrinkage of PNIPAM arms. The water-insoluble lsc-hp PSt would collapse densely and could be served as a reservoir to absorb hydrophobic chemicals in aqueous solution. The influence of overall molecular weight of lsc-hp PSt on the absorption of pyrene was studied. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Jie Zhang,Jia Liu,An Liu,Shu He,Wei Shao
In recent years, smart hydrogels have been widely applied to various types of hydrogel actuators due to their unique stimulus responsibility, such as temperature responsiveness, near-infrared (NIR) light responsiveness, pH responsiveness, etc. Herein, segmented poly (N-isopropyl acrylamide) (PNIPAM) based hydrogel actuators with both temperature and NIR light actuation behaviors were constructed. Polydopamine (PDA) was firstly used to modify MXene nanosheets to fabricate an efficient photothermal conversion material. Then they were added into PNIPAM matrix to prepare PDA@MXene/PNIPAM hydrogels. The prepared PDA@MXene/PNIPAM hydrogels exhibited three-dimensional network structure with the tensile strength of 26.84 kPa, and they were successfully assembled into segmented hydrogel actuators. The assembled segmented hydrogel actuator exhibited high bending angle of 470° in 1.75 s in 55 °C hot water and bending angle of 203° in 15 s when irradiated by 6 W/cm 2 NIR light. The segmented hydrogel actuators displayed good programmable actuation performance. Finally, they were applied as smart devices, such as hydrogel hook for grasping object, switch for controlling circuit and valve for governing fluid flow. This work provides a novel strategy for fabricating programmable hydrogel actuators and will inspire new ideas and constructions for smart soft hydrogel actuators.
研究领域:
材料科学
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智能器件
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2013
·
IF 3.554
Yan-Ling Luo,Xiao-Li Yang,Feng Xu,Ya-Shao Chen,Bin Zhang
Two kinds of thermo-sensitive poly(N-isoproplacrylamide) (PNIPAM) block copolymers, AB 4 four-armed star multiblock and linear triblock copolymers, were synthesized by ATRP with hydroxyl-terminated polybutadiene (HTPB) as central blocks, and characterization was performed by 1 H NMR, FT-IR and SEC . The multiblock copolymers could spontaneously assemble into more regular spherical core–shell nanoscale micelles than the linear triblock copolymer. The physicochemical properties were detected by a surface tension technique, nano particle analyzer, TEM, DLS and UV–vis measurements. The multiblock copolymer micelles had lower critical micelle concentration than the linear counterpart, TEM size from 100 to 120 nm and the hydrodynamic diameters below 150 nm. The micelles exhibited thermo-dependent size change, with low critical solution temperature about 33–35 °C. The characteristic parameters were affected by the composition ratios, length of PNIPAM blocks and molecular architectures. The camptothecin release demonstrated that the drug release was thermo-responsive, accompanied by the temperature-induced structural changes of the micelles. MTT assays were performed to evaluate the biocompatibility or cytotoxicity of the prepared copolymer micelles.
研究领域:
高分子化学
·
药物传递系统
·
生物材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2025
·
IF 6.3
Yan Wang,Jie Zhang,Jianlei Lu,Nan Hai,Jiawei Zhang
In this study, we developed a poly(styrene- b - N -isopropyl acrylamide) (PS- b -PNIPAm) block copolymer-incorporated hydrogel with cooling/water dual-responsive shape recovery performance. Three kinds of PS- b -PNIPAm block copolymers with different chain lengths of PNIPAm were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization, and the block copolymers could self-assemble into micelles with PNIPAm as the outer layer in water. Hydrogels were then prepared by introducing the micelles formed by the block copolymers into the polyacrylamide (PAM) network. The collapse of PNIPAm chains could be promoted by both temperature and salt, which acted as temporary crosslinks to stabilize temporary shapes, enabling cooling- and water-stimulated shape recovery. Moreover, fluorescent information could be encoded on the surface of the hydrogel and encrypted by the shape changes of the hydrogel during the shape fixing process, with the information revealed under UV irradiation after the shape recovery process, achieving information security. This approach could accelerate the evolution of shape memory hydrogels and broaden their applications across diverse fields.
研究领域:
材料科学
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高分子化学
·
智能材料
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Kequn Sun,Yinghui Dong,Lulu Yao,Mausumi Mahapatra,Yufu Xu
In this investigation, the surface tribological behavior of YG8/TC4 contacts under microgel lubrication was explored, utilizing thermal- and pH-sensitive PNIPAM-co-PAA-(IF-MoS 2 /GO) composite microgels as lubricant additives. Through the application of a ball-on-disk reciprocating tribometer, the study demonstrated the outstanding lubrication capabilities of the composite microgels. The lubrication process involving PNIPAM-co-PAA-(IF-MoS 2 /GO) composite microgels initiated a tribo-chemical reaction, leading to the generation of a larger quantity of TiS 2 with exceptional lubricating properties on the friction surface compared to alternative lubrication conditions. The effective isolation of the friction pair by PNIPAM-co-PAA composite microgels contributed to the reduction in tribo-oxidation of the sliding surfaces , while the presence of IF-MoS 2 facilitated the formation of TiS 2 . Furthermore, the facile sliding property of GO nanosheets played a crucial role in achieving overall excellent lubrication performance. The synergistic effects arising from the components in PNIPAM-co-PAA-(IF-MoS 2 /GO) composite microgels introduce a novel and effective strategy for controlling the friction and wear of YG8/TC4 contacts.
研究领域:
材料科学
·
表面工程学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 15
·期 1
·116
·
IF 4.967
Tisana Kaewruethai,Yuan Lin,Qian Wang,Jittima Amie Luckanagul
Curcumin is an extract of turmeric (Curcuma longa) which possesses anti-inflammatory, anti-cancer and wound-healing effects and has been used as an active compound in biomedical research for many years. However, its poor solubility presents challenges for its use in drug delivery systems. A modified nanogel delivery system, with PNIPAM and β-cyclodextrin grafted onto hyaluronic acid (PNCDHA), was utilized to enhance the solubility. The polymer was characterized by NMR, and the inclusion complex between curcumin and β-cyclodextrin was confirmed by FTIR. The potential of this PNCDHA polymer complex as a drug delivery vehicle was supported by a curcumin encapsulation efficiency of 93.14 ± 5.6% and the release of encapsulated curcumin at 37 °C. At a concentration of 0.5%w/vin water, PNCDHA nanogels were biocompatible with fibroblast cell line (L929) up to a curcumin concentration of 50 µM. There was a direct concentration between curcumin loading and cellular internalization. A more detailed study of the cellular internalization of PNCDHA nanogel should be considered in order to clarify cellular delivery mechanisms and to assess how its viability as a carrier may be optimized.Keywords:hyaluronic acid;β-cyclodextrin;PNIPAM;thermoresponsive;nanogel;self-assembly;curcumin
研究领域:
药物递送
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生物材料
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOBIOTECHNOLOGY
·
2024
·Vol. 22
·期 1
·1-14
·
IF 10.6
Sun Xiaodong,Li Yujie,Liu Xiaowan,Cui Dandan,Shi Yujiao,Huang Guojia
Background Properly designed second near-infrared (NIR-II) nanoplatform that is responsive tumor microenvironment can intelligently distinguish between normal and cancerous tissues to achieve better targeting efficiency. Conventional photoacoustic nanoprobes are always “on”, and tumor microenvironment-responsive nanoprobe can minimize the influence of endogenous chromophore background signals. Therefore, the development of nanoprobe that can respond to internal tumor microenvironment and external stimulus shows great application potential for the photoacoustic diagnosis of tumor. Results In this work, a low-pH-triggered thermal-responsive volume phase transition nanogel gold nanorod@poly(n-isopropylacrylamide)-vinyl acetic acid (AuNR@PNIPAM-VAA) was constructed for photoacoustic detection of tumor. Via an external near-infrared photothermal switch, the absorption of AuNR@PNIPAM-VAA nanogel in the tumor microenvironment can be dynamically regulated, so that AuNR@PNIPAM-VAA nanogel produces switchable photoacoustic signals in the NIR-II window for tumor-specific enhanced photoacoustic imaging. In vitro results show that at pH 5.8, the absorption and photoacoustic signal amplitude of AuNR@PNIPAM-VAA nanogel in NIR-II increases up obviously after photothermal modulating, while they remain slightly change at pH 7.4. Quantitative calculation presents that photoacoustic signal amplitude of AuNR@PNIPAM-VAA nanogel at 1064 nm has ~ 1.6 folds enhancement as temperature increases from 37.5 °C to 45 °C in simulative tumor microenvironment. In vivo results show that the prepared AuNR@PNIPAM-VAA nanogel can achieve enhanced NIR-II photoacoustic imaging for selective tumor detection through dynamically responding to thermal field, which can be precisely controlled by external light. Conclusions This work will offer a viable strategy for the tumor-specific photoacoustic imaging using NIR light to regulate the thermal field and target the low pH tumor microenvironment, which is expected to realize accurate and dynamic monitoring of tumor diagnosis and treatment.
研究领域:
生物医学工程
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医学影像学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLAR ENERGY
·
2024
·
IF 6
Xiangfei Kong,Yue Han,Jianjuan Yuan,Xuemei Zhang
As a bridge connecting indoor and outdoor environment, windows cause extremely high energy consumption, and near infrared light entering rooms is the primary reason for the increase of cooling load in summer. Thermochromic smart windows, which dynamically regulate light transmittance through stimulus–response mechanism, aroused enormous interest in building energy-saving. However, the development of traditional thermochromic smart windows is often limited by single function and inappropriate response temperature. Herein, a novel fully autonomous multi-stage thermal-response@storage (MTRS) smart window that responds to the ambient temperature was designed by using the thermoresponsive SPCM@PNIPAm-PAM hydrogel for energy-saving and privacy protection. The SPCM@PNIPAm-PAM hydrogel exhibited satisfactory luminous transmittance of 62.70 % and solar modulation ability ( Δ T s o l , 25 - 40 ° C =27.39 %, Δ T s o l , 40 - 55 ° C = 19.28 %). With the temperature changing from low (<28 °C) to medium (28–45 °C) to high (>45 °C), the MTRS smart window realized the multi-stage reversible transition from opaque to transparent to opaque, which achieved privacy protection at night and thermal insulation during the day. The obtained MTRS smart window achieved a peak temperature drop of 12.14 °C compared with the regular window on a certain day in the midsummer in Tianjin region. Based on this day’s temperature data, the cooling load of was calculated, and the energy saving was further calculated, which was as high as 21.37 %. The proposed work has a great significance for further development of effective smart windows and deserves attention for the future design of windows for energy saving.
研究领域:
材料科学
·
能源工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 17
·7893-7899
·
IF 3.591
L. Z. Liu,X. Y. Sun,Z. Y. Yan,B. F. Ye
Particle-based delivery systems have emerged as a powerful platform in controlled drug release. In the present study, we developed a new inverse opal hydrogel microcarrier system composed of gold nanorods (AuNRs) for near-infrared light (NIR) activated drug delivery. AuNRs with a desired aspect ratio were prepared by a seed-mediated growth method. The inverse opal hydrogel microcarriers composited with AuNRs were synthesized by negatively replicating silica colloidal crystal beads (SCCBs). The NIR-thermo response of the microcarriers was due to the NIR photothermal heating effect of AuNRs and the thermo responsive volume transition of poly(N-isopropylacrylamide) (pNIPAM) hydrogel. It was found that the NIR-controlled reversible shrinking response of the microcarriers was ideal for the controllable drug release with real-time self-reporting color indication.
研究领域:
材料科学
·
药学
·
纳米技术
·
药物递送系统
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 10
·3330
·
IF 4.927
Bingxin Mao,Cong Liu,Xu Cui,Yanhui Li,Qian Duan
A novel thermo-responsive 2,9(10),16(17),23(24)-tetrakis[(3-carboxyacrylamide) phthalocyaninato] zinc (ZnPc)-g-TiO2-g-poly(N-isopropylacrylamide) (PNIPAM) photocatalyst modified with phthalocyanines was prepared. The photocatalyst exhibited thermo-responsive properties due to the introduction of PNIPAM, which performed recovery for reuse above the lower critical solution temperature (LCST, about 26 °C). ZnPc-g-TiO2-g-PNIPAM effectively expanded the light response range to the visible light region and inhibited the recombination of electron–hole pairs, which enhanced the performance of the photocatalyst. As expected, ZnPc-g-TiO2-g-PNIPAM (0.3 g/L) exhibited excellent photocatalytic performance for the removal of Rhodamine B (RhB, 1.0 × 10−5mol/L) and methylene blue (MB, 1.0 × 10−5mol/L) under visible light, which reached 97.2% and 88.6% at 20 °C within 40 min, respectively. Furthermore, the influence of temperature upon photocatalytic performance was also investigated. When the temperature increased from 20 °C to 45 °C, the removal of RhB decreased by approximately 53.8%. The stability of the photocatalyst demonstrated that the photocatalytic activity was still above 80% for the removal of RhB after 3 cycles. Above all, this work provided an intelligent thermally responsive photocatalyst based on phthalocyanine for water purification under visible light.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）