COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Tengfang Zhang,Ziqi Wu,Huafeng Zhu,Zhikun Wang,Shuangqing Sun,Songqing Hu
Hypothesis Natural polymer chitosan (CS) has been widely used as emulsifier due to its good stability, salt-resistant, and stimuli-responsive demulsification . However, chitosan is a hydrocarbon structure molecule containing -NH 3+ and -OH with low surface activity, which is mainly suitable for some specific oil-water systems such as corn oil and sunflower oil . Appropriate hydrophilic-hydrophobic modification of chitosan by PNIPAM not only increases its surface activity but also introduces a temperature response on chitosan. Experiments Pickering emulsions (O/W) formed by CS-PNIPAM were prepared. The stability and response performance of the emulsions were investigated by observing the macroscopic states, microscopic images, droplet size distributions, emulsion emulsification indices, water partition rates, etc. Molecular dynamics and dissipative particle dynamics simulations were used to reveal the distribution pattern of the emulsifiers at the water-oil interface and clarify the stabilization and pH/temperature response mechanism of the emulsions. Findings CS-PNIPAM performs excellent emulsification in various oil phases. The addition of salt ions enhances the stability performance of the emulsion. At low pH, CS will be protonated to break the emulsion, while increasing the pH will deprotonate CS and reform the emulsion. Also, the increase of temperature to 80 °C leads to emulsion breakage due to the agglomeration of PNIPAM.
研究领域:
化学工程
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材料科学
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食品科学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
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2023
·Vol. 30
·期 4
·1-8
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IF 2.8
Li Dongxiang,Qian Xing,Huang Rui,Li Chunfang
Thermo-responsive poly( N -isopropylacrylamide) with terminal azobenzene group (PNIPAM-Azo) can show distinct property changes in response to temperature and light. In this paper, azobenzene-terminated trithiocarbonate (DDMAT-Azo) was synthesized as chain transfer agent, with which PNIPAM-Azo was prepared by reversible addition-fragmentation transfer (RAFT) polymerization of NIPAM in 1, 4-dioxane at 80 °C under N 2 atmosphere, azodiisobutyronitrile as initiator. The structure of DDMAT-Azo was characterized by nuclear magnetic resonance (NMR) and fourier transform infrared spectra, and PNIPAM-Azo was characterized by NMR spectra and Gel Permeation Chromatography (GPC). The result from GPC showed the numerical average molecular weight of PNIPAM-Azo was 3870 and its molecular weight distribution index was 1.31. Furthermore, thermo- and light-responsive hydrogel was obtained by introducing PNIPAM-Azo. Both PNIPAM-Azo and the hydrogel showed good light sensitivity and thermo sensitivity. Such double-stimuli sensitive hydrogel will be applied in biomaterials such as sensor, drug controlled release, information storage etc.
研究领域:
高分子化学
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材料科学
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生物医学工程
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产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 87
·70758-70765
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IF 3.84
Leli Wang,Ying Wu,Yongjun Men,Jianan Shen,Zhengping Liu
Single electron transfer living radical polymerization (SET-LRP) was employed to prepare thermal-sensitive starch graft poly(N-isopropylacrylamide) (Starch-g-PNIPAM) with soluble Starch-Br as macro-initiator at molecular level. And Starch-g-PNIAPM with improved graft ratio and controlled length of graft chains were obtained. The effects of molar ratio of monomer to initiator and temperature on polymerization were investigated. The thermal responsibilities investigated by 1H NMR and UV showed that the LCST ranged from 31.5 °C to 23 °C with the increase of the length of PNIPAM chains and the concentrations of copolymers. Starch-g-PNIPAM hydrogels were gained when adding N,N′-methylenebisacrylamide as crosslinking agent and the swelling and deswelling behaviors were also investigated. The obtained hydrogels possess a high equilibrium swelling ratio as high as 1826%, and an extremely rapid shrinking rate as fast as losing more than 85% of water in 5 min.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
Functional Materials Letters
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2023
·
IF 1.3
Jiaxin Li,Ruofei Wang,Diqing Ruan,Huaping Wu,Lin Cheng,Aiping Liu
Responsive hydrogels based on Poly(N-isopropylacrylamide) (PNIPAM) are known to exhibit distinctive thermosensitive properties. However, isotropic PNIPAM hydrogels with weak mechanical properties and low deformation rates tend to exhibit only regular volume expansion/contraction, which limits them to promising applications such as intelligent actuators. In order to prepare programmable hydrogel actuators with satisfactory mechanical properties and fast deformation capability, a polyvinyl alcohol/PNIPAM (PVA/PNIPAM) bilayer hydrogel with anisotropic structure is proposed by combining preprepared PVA polymer film with outstanding mechanical properties as the passive layer and thermosensitive PNIPAM hydrogel as the active layer, forming a semi-interpenetrating network structure at the interface via the hydrogen-bond interaction between PNIPAM and PVA. The microstructures, mechanical properties and actuation behaviors of bilayer hydrogel were studied by scanning electron microscope, Fourier transform infrared spectrograph, mechanical testing machine and actuation test device. Results show that the introduction of PVA can improve the tensile stress of the bilayer hydrogel from 23.6 kPa to 62.6 kPa, and favor the hydrogel actuator excellent actuation preformation with a maximum bending amplitude of 500° and a maximum bending velocity of 13°/s within first 40 s. The bilayer hydrogel is further designed to work as a fluidic system valve that can recognize various temperature solutions and control solution flow rate. This design provides a simple and practical strategy to construct responsive hydrogels with anisotropic structure for further development in the field of intelligent actuators and flexible microfluidic systems.
研究领域:
材料科学
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生物工程
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DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 9
·1248
·
IF 4.7
Pengzhi Bi,Xiuzhong Zhu,Li Tian,Jinbang Han,Wanbin Zhang,Tong Wang
In recent years, a great deal of work has been devoted to the development of thermoresponsive polymers that can be made into new types of smart materials. In this paper, a branched polymer, HTPB-g-(PNIPAM/PEG), with polyolefin chain segments as the backbone and having polyethylene glycol (PEG) and poly(N-isopropylacrylamide) (PNIPAM) as side chains was synthesized by ATRP and click reactions using N3-HTPB-Br as the macroinitiator. This initiator was designed and synthesized using hydroxyl-terminated polybutadiene (HTPB) as the substrate. The temperature-responsive behavior of the branched polymer was investigated. The lower critical solution temperature (LCST) of the branched polymer was determined by ultraviolet and visible spectrophotometry (UV-vis) and was found to be 35.2 °C. The relationship between the diameter size of micelles and temperature was determined by dynamic light scattering (DLS). It was found that the diameter size changed at 36 °C, which was nearly consistent with the result obtained by UV-vis. The results of the study indicate that HTPB-g-(PNIPAM/PEG) is a temperature-responsive polymer. At room temperature, the polymer can self-assemble into composite micelles, with the main chain as the core and the branched chain as the shell. When the temperature was increased beyond LCST, the polyolefin main chain along with the PNIPAM branched chain assembled to form the nucleus, and the PEG branched chain constituted the shell.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2025
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IF 4.7
Xue Jing,Wei Fu,Shan Xia,Guanghui Gao
Ionic conductive hydrogels have attracted extensive attention in the field of wearable sensing due to their excellent performance. However, most wearable sensors based on ionic conductive hydrogels focus on the detection of a single form of the human signal such as strain and pressure detection. To realize the comprehensive detection of human signals, the thermosensitive materials N-isopropylacrylamide (NIPAM) and acrylamide (AAm) were chemically cross-linked, and gelatin (GA) and tannic acid (TA) were introduced to construct a double-network structure hydrogel with tensile and temperature-sensing capabilities close to those of human skin. By adjusting the content of hydrophilic and hydrophobic segments of NIPAM and AAm in the first network of the hydrogel, the phase transition temperature could be controlled to realize real-time human temperature monitoring. The introduction of gelatin GA as the second network and TA as the hydrogen bond physical cross-linking center endow the hydrogel skin-like tensile strength (43 kPa) and toughness (33 kJ/m3) to adapt to the external strain changes in wearable sensing applications. Based on the skin-matching mechanical properties and good conductivity, the epidermal electrode assembled by the hydrogel had low interface impedance and excellent stability, which could be used for real-time collection of dynamic electrocardiogram (ECG) and electromyogram (EMG) physiological signals. It is believed that this hydrogel will provide new ideas for the design and manufacture of wearable devices for comprehensive health monitoring and telemedicine.
研究领域:
材料科学
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生物医学工程
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传感器技术
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 12
·5825-5831
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IF 3.3
Cheng Zhou,Shengping Dai,Xiaoshuang Zhou,Hao Zhu,Guanggui Cheng,Jianning Ding
Inspired by the stimuli-responsive ability of biological, a variety of hydrogel have been prepared by stimulus, showing great application value in actuators, soft robots, etc. However, it is still challenging to prepare a toughness hydrogel by the way of stimuli-responsive. Herein, we constructed a novel dual-network structure PNIPAM/PVA hydrogel using reversible molecular configuration conversion of PNIPAM chains. Under the stimulus of ethanol, the elastic modulus of PNIPAM/PVA hydrogel can be increased by 47 times (5 times the change of the modulus of sea cucumbers’ tissue) and the stress can be six times of the original. The dynamic borate ester bond formed by the cross-linking of PVA and borax in the hydrogel enables rapid self-healing (η > 99%) within three minutes without external stimulus in the natural environment. In addition, PNIPAM/PVA hydrogels also showed outstanding underwater reversible thermokinetic properties (>25°) based on the hydrophilic/hydrophobic conversion of PNIPAM under thermal stimulation. The successful preparation of ethanol stimulus-enhancing self-healing PNIPAM/PVA hydrogel actuators, provides a new idea for the development of the soft underwater robots.
研究领域:
材料科学
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生物仿生学
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软体机器人
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
·
IF 4.784
Huayong Luo,Xueyang Zeng,Peng Liao,Hongwei Rong,Tian C. Zhang,Z. Jason Zhang,Xiangchao Meng
Currently, there is a growing trend in employing natural biomaterials (e.g., alginate) to prepare a novel bead adsorbent for phosphorus (P) elimination. However, the utilization of alginate beads to remove and recover P from effluents possesses limitations associated with its physical characteristics such as a dense gel layer, poor mechanical strength and low stability. To overcome the limitations and improve the adsorption performances, we synthesized a novel alginate-derived bead constituted of PNIPAM network interpenetrated in alginate-Zr 4+ network (PNIPAM/SA-Zr) decorated with polyethylene glycol as a pore-forming agent, and then investigated its ability to remove and recover P from effluents. The morphology, functional groups, surface area, and mechanical strength of the beads were evaluated by SEM, FTIR , BET, and swelling analysis. The adsorption of P was investigated by varying various factors. The adsorption kinetics , isotherms, and thermodynamics were studied. Particularly, the P-loaded beads exhibited a faster desorption rate under thermal stimulus, and remained good desorption efficiency and reusability within five consecutive cycles. Zeta-potential and XPS results revealed that the adsorption mechanisms were related to electrostatic interactions, ligand exchange, and the formation of inner-sphere complexes. The beads possessed favorable fixed-bed column operation performances for P removal and recovery from real wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Ziqing Zhao,Xiaoliang Ma,Rui Chen,Hui Xue,Jiehua Lei,Hui Du,Zexin Zhang,Hong Chen
Because of the excellent film-forming ability of poly(N-isopropylacrylamide) (PNIPAM) microgel and high-efficient bactericidal property of quaternary ammonium salt (QAS), QAS-based PNIPAM (QAS-PNIPAM) microgels are synthesized and employed to modify the surface of a range of commonly used materials including metal, plastic, and elastomer. Bacterial culture is carried out on such QAS-PNIPAM microgel-modified surfaces to examine the viability of the attached bacteria. It is found that the bactericidal efficiency is nearly 100% on the modified surfaces of all the studied materials. We attribute the high-efficient bactericidal performance of QAS-PNIPAM microgel film to the QAS component rather than the topography of the microgel film itself. In addition, the microgel film is robust and shows great integrity even after culture of the bacteria and repeated rinses, and the cell experiment demonstrates that this microgel film is cyto-compatible. Therefore, such a simple, versatile method of preparing antibacterial films paves the way for future bactericidal applications.
研究领域:
材料科学
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生物医学工程
·
化学
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产品关联
DOI
PubMed
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 8
·085708
·
IF 1.449
Bian Wang,Qingjuan Wang,Yuting Zhu,Litao Kang,Jingxin Zhu,Fuyi Jiang,Wei Du,Dongjiang You,Zongtao Zhang,Feng Gao
Cesium tungsten bronze (CsxWO3) is an important functional material for energy efficient windows, showing excellent near infrared (NIR) shielding ability but no optical switching ability. In this paper, we demonstrate a photo-/thermo-dual-responsible CsxWO3/PNIPAM composite by dispersing CsxWO3 nanoparticles into PNIPAM hydrogels. Combination of the photothermic conversion ability of CsxWO3 with the thermochromic property of PNIPAM makes this hydrogel responds to both thermo- and photo-stimuli. In sunlight, the CsxWO3 component converts the absorbed infrared light into heat, triggering the phase transition of PNIPAM and switching the hydrogel into visibly opaque state (for example, transmittance decreased from 58% down to 15% at 590 nm). At the same time, an ambient temperature >32 °C can also initiate the phase transition of PNIPAM. Therefore, a photo- and/or thermo-derived transition between a 'transparent NIR-shielding' state and a 'full-solar-spectrum shielding' state is achieved, making it highly attractive for the applications as energy efficient windows for buildings in hot climate.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2014
·
IF 1.357
Yan-Ling Luo,Jing-Yu Fu,Feng Xu,Ya-Shao Chen,Bin Zhang
Thermo-sensitive poly(N-isoproplacrylamide)m-block-hydroxyl-terminated polybutadiene-block-poly(N-isoproplacrylamide)m (PNIPAMm-b-HTPB-b-PNIPAMm, m = 1 or 2) block copolymers, AB4 four-armed star multiblock and linear triblock copolymers, were synthesized by ATRP with HTPB as central blocks, and characterization was performed by 1H NMR, Fourier transform infrared, and size exclusion chromatography. 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, nanoparticle analyzer, transmission electron microscope (TEM), dynamic light scattering, 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 of 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
·
药物递送系统
·
生物材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 44
·49375
·
IF 2.52
Liai Yang,Ting Zhang,Wei Sun
To construct an actuator with biocompatibility and potential use in biomedicine field, a light-driven actuator composed of reduced graphene oxide (rGO)/poly (N-isopropyl acrylamide) (PNIPAM) and poly (ethylene glycol) diacrylate (PEGDA) hydrogel is constructed. First, rGO/PNIPAM hydrogel is prepared by free radical polymerization and l -ascorbic acid reduction, of which the surface temperature increases quickly under near-infrared (NIR) laser indicating the efficient photothermal conversion of rGO. The results of cytotoxicity tests demonstrate that rGO/PNIPAM is biocompatible and has no obvious toxicity to myoblast line C2C12 cells. Second, bilayer hydrogel composed of rGO/PNIPAM and PEGDA is prepared using a similar method layer-by-layer. The bilayer strip bends towards rGO/PNIPAM under NIR laser. The bending is improved after reduction. The laser power density has a strong impact on the bending rate and degree. The reversible bending deformation indicates the structural stability. All the above results approve that the bilayer actuator has great potential to be applied in biomedicine fields such as organ-on-chip, drug-carrier, or surgical aid.
研究领域:
材料科学
·
生物医学工程
✓ 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）