图1 产生和消去同时进行。流道断面(A)和表面(B)变化图;(C)用共聚焦测试得到的流道变化剖面图;(D)流道变化后的3D图[24]

Fig.1 Concurrent growth and removal. Cross section (A) and top down (B) view of a shifting channel. (C) Channel profiles obtained with confocal metrology. Shifted channel data from c is a profile through the middle of d. (D) 3D view of the channel after modification[24]

图2 界面聚合产生图灵结构。(A)反应-扩散过程中活化-抑制反应作用示意图,导致图灵结构的反应依赖竞争的活化(红)和抑制(蓝)动力学路径。(B)区域活化、横向抑制产生的空间结构。在二维层面,图灵结构以点状和条纹状形式展现[25]

Fig.2 Turing-type structures in interfacial polymerization. (A) Schematic diagram of activator-inhibitor interaction in a reaction-diffusion process. Reactions leading to Turing structures rely on competing activation(red) and inhibition (blue) kinetic pathways. (B) Spatial representation of local activation and lateral inhibition. In two dimensions, Turing structures generally consist of spots or stripes[25]

图3 光诱导基质膨胀的示意图。(A)丙烯酸4-羟基丁酯(HBA),丙烯酸邻硝基苄酯(NBA,促进剂),I-819(光引发剂),1,6-己二醇二丙烯酸酯(HDDA)。(B)膨胀发生的种子。HBA、HDDA、I-819和酯基转移催化剂作为膨胀发生的营养液。(C)选择性紫外光照引发基质膨胀。光分解NBA基团产生离子键,使得液体能扩散至光照区域。(D)通过光聚合形成新的聚合物网络。液体扩散进入后使原有聚合物链被拉伸。(E)新生长出的部分通过原聚合物网络和新形成的聚合物网络之间的酯交换反应实现均质化[30]

Fig.3 Schematic of light-induced growth from swollen substrates. (A) Growable seed made from 4-hydroxybutyl acrylate(HBA), o-nitrobenzyl acrylate(NBA, promoter), Irgacure 819(I-819, photoinitiator) and 1,6-hexanediol diacrylate(HDDA). (B) Swollen seed. The mixture of HBA, HDDA, photoinitiator(I-819), and transesterification catalyst(benzensulfonic acid(BZSA)) were used as the nutrient solution for swelling. (C) Swollen substrate under selective UV irradiation. Photolysis of NBA units generated dissociable ionic groups to induce liquid diffusion into the irradiated region. (D) New polymer network formed via photopolymerization. Liquid components diffused in, and the polymer chains in the original network were stretched. (E) The grown part was homogenized via transesterification reactions between the original and newly formed polymer networks[30]

图4 紫外光和电场协同作用调控表面拓扑形貌。(A)室温下初始状态,(B)紫外光照下,(C)在AC电场下(16 Vrms·μm-1, 900 kHz),(D)紫外光和电场协同作用下的3D拓扑形貌图[38]

Fig.4 UV light and electric field orthogonally and synergistically actuated surface topographies. 3D images showing the surface topography of (A) the initial state at RT, (B) during UV illumination, and (C) under an AC electric field (16 Vrms·μm-1, 900 kHz), (D) the combination of UV illumination and AC field actuation[38]

图5 2D有序图案制备。(A)样品制备过程示意图,含蒽聚合物及其二聚体(DLAP)的化学结构及动态光二聚反应。(B)梯度光交联体系的机械失稳模型。“E”和“h”分别表示各层的表面模量和厚度,下标f、g、s、t分别表示最外层、梯度层、基底和整个聚合物膜[39]

Fig.5 Preparation of 2D ordered patterns. (A) Schematic of the preparation procedure of the samples and the involved chemical structures and dynamic photodimerization reaction of the light-responsive anthracene-containing polymer and its dimer (DLAP). (B)The proposed model for the mechanical instability in a gradient photo-crosslinked system. “E” and “h” refer to surface modulus and thickness of the layers, respectively, and the subscripts f, g, s, and t refer to the top-layer film, gradient layer, bulk substrate, and total polymer film, respectively[39]

图6 (A)基于D-A反应实现可逆起皱的策略。对呋喃修饰的聚丙烯酸丁酯/双马来酰亚胺(FBA/BMI)覆盖的膜进行70 ℃加热4 h实现起皱的形成(C)和120 ℃处理20 min擦除起皱图案(B)。上层涂层厚度大概为75 nm[45]

Fig.6 (A) Strategy for a reversible wrinkle pattern based on a reversible Diels-Alder reaction; 3D AFM images demonstrating (C) the generation and (B) erasure of the reversible wrinkle pattern on the FBA/BMI coated film by the D-A reaction at 70 ℃ for 4 h, and the retro D-A reaction at 120 ℃ for 20 min. The thickness of the top layer is approximately 75 nm[45]

图7 湿度响应加密装置制备流程图[47]

Fig.7 Flow chart for the preparation of a moisture-responsive encryption device[47]

图8 (A)平行取向的电纺纤维在与预拉伸基底上实现波浪形纳米纤维形成过程示意图。(B)波长为(4.7 ± 1.3)和(2.3 ± 0.7)μm的波浪形纳米纤维在预拉伸率为40%和100%上分别形成。褐色和红色箭头分别表示取向和拉伸率[49]

Fig.8 (A) Schematic of wave-like nanofiber synthesis by relaxation of electrospun layers of parallel-aligned nanofibers on prestretched substrates. (B) Relaxation of the substrates gives rise to wave-like nanofibers with wavelengths of (4.7 ± 1.3) and (2.3 ± 0.7) μm at 40% and 100% prestretching, respectively. Black and red arrows indicate alignment direction and stretch-compression ratio, respectively[49]

图9 (A)二甲亚砜(DMSO)溶液中的聚甲基丙烯酸缩水甘油基酯(PGMA)聚合物刷在10 nN 力的作用下得到的AFM拓扑形貌图(24 × 24 μm)。(B)与A一样大小平面的中心5.46 × 4.80 μm区域450 nN力以12.52 μm/s速度扫描256次。(C)图B中心区域功能化表面。(D)图B中心区域410~430 nm波长范围的荧光显微照片。标尺为5.0 μm[51]

Fig.9 (A) AFM topographic image (24 × 24 μm) of a PGMA brush acquired in DMSO under 10 nN force. (B) The same area as A after the central 5.46 × 4.80 μm region was subjected to high-force (450 nN) scans at 12.52 μm/s with 256 lines. (C) The surface functionalities across the middle of image B. (D) Fluorescence microscopy image of the same region as B collected from 410 to 430 nm. All scale bars are 5.0 μm[51]

图10 用于动态磁响应结构(DMRWs)在磁场作用下实现倾斜示意图。磁场的增强,弯曲角度(βtilt)越大(A,B);当磁铁远离DMRWs,磁场减弱,弯曲角度(βtilt)减小(B,C)[60]

Fig.10 The illustration of the neodymium iron boron magnet used to tilt the DMRWs. With the increasing magnetic (A,B) field by getting closer magnet, the tilt angles βtilt of DMRWs increase. With the decreasing magnetic (B,C) field by getting farther magnet, the tilt angles βtilt of DMRWs decrease[60]

图11 表面微纳复合结构形变和恢复过程示意图[63]

Fig.11 Schematic illustration of surface hierarchical micro/nanostructure deformation and recovery process[63]

图12 3D分层结构动态起皱策略和表征。(A)通过光控D-A反应制备分层结构过程和结构示意图。(B)BMI光诱导扩散示意图。(C)光诱导BMI扩散过程中形成的浮雕图案的激光共聚焦扫描图(LSCM);插图为浮雕图案的剖面图。(D)75 ℃处理90 min使样品C得到时空结构的LSCM图,插图表示起皱的轮廓线。(E)对样品C进行75 ℃处理90 min后得到的起皱结构AFM图。(F)BMI和含有呋喃的聚合物(PSFB)以及通过BMI光二聚实现的光控D-A反应机理[65]

Fig.12 The strategy and characterization for 3D hierarchical pattern with dynamic wrinkles. (A) The process for fabrication of hierarchical pattern with dynamic wrinkles through photocontrolled D-A reaction and its 3D model; (B) the scheme of photoinduced diffusion of bismaleimide(BMI); (C) laser scanning confocal microscopy(LSCM) images of relief pattern caused by photoinduced diffusion of BMI; the inset shows the typical profile of the relief pattern; (D) the LSCM image of the wrinkle with spatial-temporal features obtained by the sample C being heated at 75 ℃ for 60 min; the inset is the outline of a wrinkle in a line-marked place; (E) the AFM image of hierarchical wrinkle obtained by the sample C being heated at 75 ℃ for 90 min; (F) the chemical structure of BMI and furan-containing polymer(PSFB) and the proposed mechanism for photocontrolled D-A reaction through photodimerization of BMI[65]

图13 (A~C)(PEI/PAA-N3)10三种图案SEM图。每一种图案都有不同形状的平整区域阵列(圆形、正方形、三角形)。插图分别表示(PEI/PAA-N3)10图案的整体外观。(D)平整和结构区域结合处的高倍数SEM图。(E)条带SEM图。(F)图E中形貌特性的高倍数SEM显示图[66]

Fig.13 (A~C) SEM images of three patterned (PEI/PAA-N3)10 films. Each of these has an array of flat regions with varied geometries (circle, square, and triangle). Insets in images b, c, and d are the overall appearance of these three patterned (PEI/PAA-N3)10 films. (D) High-magnification SEM image shows the junction area between the flat region and the structured region in imaged. (E) SEM image of a patterned surface with an array of stripes. (F) High-magnification SEM image shows the morphological features of the patterned surfaces in image E[66]