智能高分子开关膜的制备方法研究进展

智能高分子开关膜是将智能高分子与非刺激响应型基材膜结合而成。由于智能高分子能够响应外界刺激发生亲疏水性转变和构象变化,智能高分子开关膜也能根据外部刺激改变自身的表面/界面特性、渗透通量或选择透过性。智能高分子膜被用作抗污染滤膜、亲和分离、酶反应的起/停控制以及控制释放等。智能高分子开关膜的制备方法直接影响其环境刺激响应特性、稳定性和可重复制备性等。因此,系统介绍了基材膜修饰法、基材修饰成膜法和共混成膜法等3种智能高分子开关膜制备方法的定义、分类、机理和研究进展,并对比了3种方法的优缺点。基材膜修饰法研究最多,而共混成膜法最有望用于大规模制备智能高分子膜。本文以期为高效制备具有稳定、优良响应特性的智能高分子开关膜提供指导和参考。     

温度响应型智能开关膜的“开/关”长效性研究

系统研究了采用不同接枝方法制备的温度响应型智能开关膜的"开/关"长效特性.采用等离子体诱导填孔接枝聚合法和原子转移自由基聚合法,成功制备了具有聚N-异丙基丙烯酰胺(PNIPAM)接枝开关的温度响应型智能开关膜.研究表明,采用不同接枝方法制备的智能开关膜的最佳接枝率范围分别为3.6%~6.9%和10.8%~26.1%,最佳相对温敏开关系数分别为100和80.60余次"高温-低温"循环水通量实验表明,所制备的温度响应型智能开关膜均具良好的可逆性和"开/关"长效性.实验结果为环境刺激响应开关膜的制备和应用提供了重要的参考.     

环境刺激响应型智能膜材料的研究进展

在当前膜材料发展中,制备可随外界环境刺激变化而发生性能改变的环境刺激响应型智能膜材料,达到性能可控目的,实现膜的"智能化",依旧是膜研究领域中的热点方向。重点综述了目前热点研究的环境刺激响应型智能膜材料,概述了相关的膜功能以及膜应用过程,并对未来环境刺激响应型智能膜材料的应用和研究前景进行了展望。     

环境感应式控制释放开关膜的研究进展

药物控制释放是目前十分活跃的研究领域，因为它具有长效、高效、靶向、低副作用等特点，因此具有智能开关的环境感应式控制释放膜成了目前膜学与医用高分子材料的研究热点．文中基于大量研究文献，主要综述了温度感应型、pH感应型以及葡萄糖浓度感应型等环境感应式控制释放开关膜的研究进展。     

pH响应型微囊膜的研究与应用进展

综述了pH响应型微囊膜的研究和应用进展,着重介绍了pH响应型微囊膜的制备与性能方面的研究成果,以及pH响应型微囊膜在结肠靶向式药物送达、蛋白质的控制释放、酶反应的“起／停”控制、脱氮过程pH控制等方面的应用成果．     

等离子体诱导接枝聚合法制备pH感应开关膜

利用等离子体诱导填孔接枝聚合法在聚偏氟乙烯多孔膜上接枝聚甲基丙烯酸pH感应型开关,系统研究了接枝率对膜的pH感应开关特性的影响.结果表明,开关膜的接枝率对膜的过滤通量、pH感应开关系数和膜孔径感应pH变化倍数都有重要的影响.接枝率≤5.98%时,pH感应开关系数和膜孔径感应pH变化倍数均随接枝率的增加而增加;而对于接枝率＞5.98%的膜,pH感应开关系数和膜孔径pH感应变化倍数随接枝率的增加而减少,直至膜开关系数和膜孔径pH感应变化倍数趋近于1.为了获得较好的开关性能,必须将膜的接枝率控制在适当的范围内.     

智能微球复合膜的制备及其Pb~(2+)检测性能研究

通过将Pb~(2+)响应性聚(N-异丙基丙烯酰胺-共聚-苯并-18-冠-6-丙烯酰胺)智能微球结合至尼龙6/聚醚砜复合膜的膜孔中作为Pb~(2+)响应型智能开关,成功构建了一种能检测痕量Pb~(2+)浓度的高灵敏智能微球复合膜.系统研究了智能微球的形貌结构及Pb~(2+)响应性,确定了37℃时其Pb~(2+)响应性能最佳.系统研究了智能微球复合膜的形貌结构及Pb~(2+)检测性能,发现其检测限可低至10~(-7) mol/L,低于工业废水中Pb~(2+)含量标准,展现出高灵敏Pb~(2+)检测特性.研究结果为制备新型高灵敏Pb~(2+)浓度智能检测系统提供了新思路.     

具有pH开关特性的乙烯-乙烯醇共聚物膜的制备与性能

以乙烯-乙烯醇共聚物(EVAL)膜为基膜,甲基丙烯酸二甲基氨基乙酯(DMAEMA)为功能单体,采用分步紫外接枝法制备pH响应性EVAL-g-PDMAEMA膜。采用紫外可见吸收光谱、红外光谱、X射线光电子能谱、场发射电镜及X射线能量色散谱对接枝前后EVAL膜的化学组成、形貌与接枝链分布进行研究,并考察接枝条件对膜接枝率及pH开关性能的影响。结果表明,PDMAEMA链可成功接枝至EVAL膜上,其在EVAL膜表面和膜孔内均有存在,膜孔内PDMAEMA接枝量随接枝率增高而增高。EVAL-g-PDMAEMA膜pH开关性能主要受膜孔内PDMAEMA接枝量的影响,当二苯甲酮(BP)浓度为60 g/L,BP固定时间为5 min,单体接枝时间为20 min时,膜接枝率最高,pH开关性能最为显著。     

温敏聚氨酯软段的结晶行为及其智能响应特性

采用两步溶液共聚技术制备了一种温敏聚氨酯材料,并对其软段的结晶行为以及智能响应特性和机理进行了分析。结果表明:温敏聚氨酯具有典型的嵌段和微相分离结构,软段和硬段各具独立的结晶熔融转变温度(软段的结晶熔融转变温度定义为开关温度),且软段的结晶具有较好的热致可逆性。当温度低于开关温度时,软段具有完整的结晶形态,温敏聚氨酯膜的内部自由体积孔洞尺寸和透汽性均较低;当温度高于开关温度时,软段结晶完全熔融、消失,同时膜的内部自由体积孔洞尺寸和透汽性均明显增大,显示了温敏特性。温敏聚氨酯软段的相态转变决定材料的智能响应特性,并且这一过程可通过外界温度的改变加以控制。     

负载蓝莓花青素的壳聚糖基智能指示膜监测花蛤新鲜度的研究

目的 研发一种可视化的新鲜度指示薄膜，探究其在花蛤新鲜度监测中的可行性。方法 以对pH敏感的蓝莓花青素为指示剂，壳聚糖为基质，通过复合明胶、乳酸链球菌素（Nisin）和迷迭香精油制备5种智能指示膜，研究其pH敏感性、颜色响应性、微观结构、阻隔特性、力学性能、含水率、水溶性、抗氧化、抗菌等特性。结果 蓝莓花青素溶液在pH值为3～12内颜色响应明显。随着膜组分的增加，薄膜微观结构的粗糙度增加，而水蒸气阻隔性能逐渐降低。Nisin和迷迭香精油的添加显著增强了抗氧化和抗菌能力。壳聚糖/Nisin/迷迭香精油–蓝莓花青素（CSNR–ATH）膜的紫外线阻隔性能较优而水溶性低。CSNR–ATH膜在花蛤的冷藏过程中能灵敏反映花蛤新鲜度的变化，复合指示膜由淡绿色变为黄绿色。结论 负载蓝莓花青素的壳聚糖基智能指示膜为花蛤新鲜度的监测提供了一种新的选择。     

Zwitterionic Nanohydrogels–Decorated Microporous Membrane with Ultrasensitive Salt Responsiveness for Controlled Water Transport

Highly sensitive responsiveness is vital for stimuli‐responsive membranes. However, it is a great challenge to fabricate stimuli‐responsive membranes with ultrahigh gating ratio (the ratio of the salt solution permeating flux to the pure water permeating flux) and high response speed simultaneously. In this work, a salt‐responsive membrane with an ultrahigh gating ratio is fabricated via a facile strategy by grafting zwitterionic nanohydrogels onto a poly(acrylic acid)‐grafting‐poly(vinylidene fluoride) (PAA‐g‐PVDF) microporous membrane. Due to the synergistic effect of two functional materials, PAA chains and zwitterionic nanohydrogels tethered on PAA chains, this stimuli‐responsive membrane exhibits an ultrasensitive salt responsiveness with a gating ratio of up to 8.76 times for Na⁺ ions, 89.6 times for Mg²⁺ ions, and 89.3 times for Ca²⁺ ions. In addition, such zwitterionic nanohydrogels–grafted PAA‐g‐PVDF (ZNG‐g‐PVDF) membranes exhibit very rapid responses to stimuli. The permeating flux changes swiftly while altering the feed solution in a continuous filtration process. The excellent salt‐responsive characteristics endow such a ZNG‐g‐PVDF membrane with great potential for applications like drug delivery, water treatment, and sensors.     

Bioinspired Smart Gating of Nanochannels Toward Photoelectric‐Conversion Systems

Learning from nature has inspired the creation of intelligent materials to better understand and imitate biology. Recent studies on bioinspired responsive surfaces that can switch between different states are shown, which open up new avenues for the development of smart materials in two dimensions. Based on this strategy, biomimetic nanochannel systems have been produced by introducing responsive molecules, which closely mimic the gating mechanism of biological nanochannels and show potential applications in many fields such as photoelectric‐conversion systems demonstrated in this paper.     

A Magnetic Gated Nanofluidic Based on the Integration of a Superhydrophilic Nanochannels and a Reconfigurable Ferrofluid

The design of intelligent gating in nanoscale is the subject of intense research motivated by a broad potential impact on science and technology. However, the existing designs require complex modification and are unstable, which restrict their practical applications. Here, a magnetic gated nanofluidic is reported based on the integration of superhydrophilic membranes and reconfigurable ferrofluid, which realizes the gating of the nanochannel by adjusting the steric configuration of the ferrofluid. This system could achieve ultrahigh gating ratio up to 10 000 and excellent stability up to 130 cycles without attenuation. Experiments and theoretical calculations demonstrate that the switch is controlled by the synergy of magnetic force and the interfacial tension. The introduction of ferrofluid and superhydrophilic nanochannels in this work presents an important paradigm for the nanofluidic systems and opens a new and promising avenue to various developments in the fields of materials science, which may be utilized in medical devices, nanoscale synthesis, and environmental analysis.     

Plasmonic Retrofitting of Membrane Materials: Shifting from Self‐Regulation to On‐Command Control of Fluid Flow

This work calls for a paradigm shift in order to change the operational patterns of self‐regulated membranes in response to chemical signals. To this end, the fabrication of a retrofitting material is introduced aimed at developing an innovative generation of porous substrates endowed with symbiotic but fully independent sensing and actuating capabilities. This is accomplished by transferring carefully engineered plasmonic architectures onto commercial microfiltration membranes lacking of such features. The integration of these materials leads to the formation of a coating surface proficient for ultrasensitive detection and “on‐command” gating. Both functionalities can be synergistically modulated by the spatial and temporal distribution of an impinging light beam offering an unprecedented control over the membrane performance in terms of permeability. The implementation of these hybrid nanocomposites in conventional polymeric porous materials holds great potential in applications ranging from intelligent fluid management to advanced filtration technologies and controlled release.     

环境响应型控制释放微载体材料研究新进展

环境响应型智能微载体材料可以响应温度、pH值、磁场、化学物质等环境刺激的微小变化,实现物质的自律式控制释放,在药物送达、酶和细胞固定化、分离纯化等领域显示出突出的优越性,具有广泛应用前景。综述了环境响应型控制释放微载体材料的研究进展,介绍了"开-关模式"控释微囊和"突释模式"控释微囊等环境响应型控释微载体材料的研究新进展,着重介绍了温度响应型、血糖浓度响应型、离子识别响应型"开-关模式"控释微囊以及温度响应型、pH响应型、离子识别响应型"突释模式"控释微囊的制备与性能方面的研究新成果。目前,环境响应型智能微载体材料仍多处于基础研究阶段,还需要进一步系统深入研究和开发完善。     

Engineering Biomimetic Platesomes for pH‐Responsive Drug Delivery and Enhanced Antitumor Activity

Biomimetic camouflage, i.e., using natural cell membranes for drug delivery, has demonstrated advantages over synthetic materials in both pharmacokinetics and biocompatibility, and so represents a promising solution for the development of safe nanomedicine. However, only limited efforts have been dedicated to engineering such camouflage to endow it with optimized or additional properties, in particular properties critical to a “smart” drug delivery system, such as stimuli‐responsive drug release. A pH‐responsive biomimetic “platesome” for specific drug delivery to tumors and tumor‐triggered drug release is described. This platesome nanovehicle is constructed by merging platelet membranes with functionalized synthetic liposomes and exhibits enhanced tumor affinity, due to its platelet membrane–based camouflage, and selectively releases its cargo in response to the acidic microenvironment of lysosomal compartments. In mouse cancer models, it shows significantly better antitumor efficacy than nanoformulations based on a platesome without pH responsiveness or those based on traditional pH‐sensitive liposomes. A convenient way to incorporate stimuli‐responsive features into biomimetic nanoparticles is described, demonstrating the potential of engineered cell membranes as biomimetic camouflages for a new generation of biocompatible and efficient nanocarriers.     

3D Porous Hydrogel/Conducting Polymer Heterogeneous Membranes with Electro‐/pH‐Modulated Ionic Rectification

Heterogeneous membranes composed of asymmetric structures or compositions have enormous potential in sensors, molecular sieves, and energy devices due to their unique ion transport properties such as ionic current rectification and ion selectivity. So far, heterogeneous membranes with 1D nanopores have been extensively studied. However, asymmetric structures with 3D micro‐/nanoscale pore networks have never been investigated. Here, a simple and versatile approach to low‐costly fabricate hydrogel/conducting polymer asymmetric heterogeneous membranes with electro‐/pH‐responsive 3D micro‐/nanoscale ion channels is introduced. Due to the asymmetric heterojunctions between positively charged nanoporous polypyrrole (PPy) and negatively charged microscale porous hydrogel poly (acrylamide‐co‐acrylic acid) (P(AAm‐co‐AA)), the membrane can rectify ion transmembrane transport in response to both electro‐ and pH‐stimuli. Numerical simulations based on coupled Poisson and Nernst–Plank equations are carried out to explain the ionic rectification mechanisms for the membranes. The membranes are not dependent on elaborately fabricated 1D ion channel substrates and hence can be facilely prepared in a low‐cost and large‐area way. The hybridization of hydrogel and conducting polymer offers a novel strategy for constructing low‐cost, large‐area and multifunctional membranes, expanding the tunable ionic rectification properties into macroscopic membranes with micro‐/nanoscale pores, which would stimulate practical applications of the membranes.     

微流控技术构建单分散微囊膜的研究新进展

单分散微囊膜在控制释放领域显示出许多优势而备受重视,而近期出现的微流控技术为制备单分散微囊膜提供了可靠的新方法.综述了微流控技术构建单分散微囊膜的研究新进展,着重介绍了微流控技术制备基于乙基纤维素、壳聚糖和海藻酸钙等生物相容性材料的单分散微囊膜以及基于聚N-异丙基丙烯酰胺的温敏型和离子识别型的单分散微囊膜的研究现状.     

Red Blood Cells for Glucose‐Responsive Insulin Delivery

Glucose‐responsive delivery of insulin mimicking the function of pancreatic β‐cells to achieve meticulous control of blood glucose (BG) would revolutionize diabetes care. Here the authors report the development of a new glucose‐responsive insulin delivery system based on the potential interaction between the glucose derivative‐modified insulin (Glc‐Insulin) and glucose transporters on erythrocytes (or red blood cells, RBCs) membrane. After being conjugated with the glucosamine, insulin can efficiently bind to RBC membranes. The binding is reversible in the setting of hyperglycemia, resulting in fast release of insulin and subsequent drop of BG level in vivo. The delivery vehicle can be further simplified utilizing injectable polymeric nanocarriers coated with RBC membrane and loaded with Glc‐Insulin. The described work is the first demonstration of utilizing RBC membrane to achieve smart insulin delivery with fast responsiveness.