A spin-based magnetic scanning microscope for in-situ strain tuning of soft matter

We present a magnetic scanning microscope equipped with a nitrogen-vacancy(NV) center scanning probe that has the ability to mechanically tune the strain of soft matter in-situ. The construction of the microscope and a continuous straintuning sample holder are discussed. An optically detected magnetic resonance protocol utilized in the imaging is described.In order to show the reliability of this microscope, the strain conduction is estimated with finite element simulation, and xray diffraction is required for calibration when freestanding crystal films are under consideration. A magnetic imaging result is displayed to demonstrate the nano-scale imaging capability. The microscope presented in this work is helpful in studying strain-coupled magnetic physics such as magnetic phase transition under strain and strain-tuned cycloidal orientation tilting.

Survival at Tumor Recurrence in Soft Matter

Survival at tumor recurrence in soft matter, after chemotherapy, is assessed by RNA folding. It is shown that this recurrence is starting with development of a fluidlike globule;it changes the energy of soft matter;it proceeds as a resonant mixing;and at the end it causes diffusion. This diffusion is interpreted as metastasis in soft matter. A tumor memory is designed for its recurrence oscillations. These oscillations are marked as positive or negative according to their influence on life stabilization or destabilization. It is demonstrated that a tumor memorizes two types of recurrences. The intensity of chemotherapy in soft matter for a tumor with such memory is obtained. Survival at tumor recurrence in soft matter, after chemotherapy, is assigned to one of the five regions of the phase diagram of the “thermalized” tumor by microenvironment. To each of these regions is collated a breast cancer survival class. It is found that the survival at tumor recurrence in soft matter, after chemotherapy, well represents actual survival of 32 patients with breast cancer.

Skin formation in drying a film of soft matter solutions：Application of solute based Lagrangian scheme

When a film of soft matter solutions is being dried, a skin layer often forms at its surface, which is a gel-like elastic phase made of concentrated soft matter solutions. We study the dynamics of this process by using the solute based Lagrangian scheme which was proposed by us recently. In this scheme, the process of the gelation（i.e., the change from sol to gel） can be naturally incorporated in the diffusion equation. Effects of the elasticity of the skin phase, the evaporation rate of the solvents, and the initial concentration of the solutions are discussed. Moreover, the condition for the skin formation is provided.

Survival Reassessment at Tumor Recurrence in Soft Matter

The paper reassesses a survival at tumor recurrence in soft matter. First, the stability of structural motifs under shear in clusters of dipolar spheres is characterized. Next, there are introduced transitions between polymer knots and rhythms of these transitions are obtained. The sensor is built for these rhythms. Treatment, with a tensile force protocol, is modeled, when the tumor in soft matter is observed by the above sensor. Survival probability, at tumor recurrence in soft matter, is defined for the treatment with a tensile force protocol. It is stated that the survival probability at a tensile force protocol treatment in soft matter confirms or specifies the prognostic survival of 32 patients with breast cancer.

Spherical Packing Superlattices in Self-Assembly of Homogenous Soft Matter:Progresses and Potentials

The construction of complex superlattices using homogenous soft matter has great potential for the bottom-up fabrication of complex,nanoscale structures.This topic is not only interested in scientific exploring for new concepts of supramolecular crystals with nanometer in sizes,which is about thousand times larger in volumes than those of normal crystals,but also practically important to provide construction principles of metamaterials which are artificially structured materials for controlling and manipulating light,sound,and other physical behaviors.These systems have fast assembly kinetics and convenient processing procedures,making them ideal for large-scale superlattice production.In this perspective,we focus on recent developments in the construction of complex spherical packing superlattices using homogenous soft self-assemblies.We discuss the general mechanism of those formations of supramolecular motifs and provide an overview of the spherical packing superlattices self-assembled by homogenous soft matters based on different volume asymmetry.Additionally,we outline the potentials of utilizing this approach in constructing novel superlattices as well as its future challenges.

A ＂green pathway＂ different from simple diffusion in soft matter： Fast molecular transport within micro/nanoscale multiphase porous systems

Soft matter has attracted extensive attention due to its special physical/chemical properties and holds great promise in many applications. However, obtaining a detailed understanding of both complex fluid and mass transport in soft matter, especially in hierarchical porous media of biological tissues, still remains a huge challenge. Herein, inspired by fast tracer transport in loose connective tissues of living systems, we observed an interesting phenomenon of fast molecular transport in situ in an artificial hierarchical multiphase porous medium （a micrometer scale hydrophobic fiber network filled with nanometer scale hydrophilic porous medium）, which was simply fabricated through electro- spinning technology and polymerization. The transportation speed of molecules in the micrometer fiber network is larger than simple diffusion in nanometer media, which is better described by Fick＇s law. We further proved that the phenomenon is based on the nanoconfined air/water/solid interface around the micrometer hydrophobic fibers. We focus on the key factors, referring to SA, （the confined multiphase area around the microfibers） and Nc （the connectivity node degree of the skeletal portion in the nanometer hydrogel medium）. Next, a quantitative parameter, VTCM （transport chance mean-value）, was introduced to describe the molecular transport capability of the fiber network within hierarchical multiphase porous systems. These fundamental advances can be applied de novo to understand the process of so-called simple diffusion in biological systems, and even to re-describe many molecular events in biologically nanoconfined spaces.

Toward Rational and Modular Molecular Design in Soft Matter Engineering

This essay discusses some preliminary thoughts on the development of a rational and modular approach for molecular design in soft matter engineering and proposes ideas of structural and functional synthons for advanced functional materials. It echoes the Materials Genome Initiative by practicing a tentative retro-functional analysis （RFA） scheme. The importance of hierarchical structures in transferring and amplifying molecular functions into macroscopic properties is recognized and emphasized. According to the role of molecular segments in final materials, there are two types of building blocks： structural synthon and functional synthon. Guided by a specific structure for a desired function, these synthons can be modularly combined in various ways to construct molecular scaffolds. Detailed molecular structures are then deduced, designed and synthesized precisely and modularly. While the assembled structure and property may deviate from the original design, the study may allow further refinement of the molecular design toward the target function, The strategy has been used in the development of soft fullerene materials and other giant molecules. There are a few aspects that are not yet well addressed： （1） function and structure are not fully decoupled and （2） the assembled hierarchical structures are sensitive to secondary interactions and molecular geometries across different length scales. Nevertheless, the RFA approach provides a starting point and an alternative thinking pathway by provoking creativity with considerations from both chemistry and physics. This is particularly useful for engineering soft matters with supramolecular lattice formation, as in giant molecules, where the synthons are relatively independent of each other.

Role of Soft Matter in the Sandwich Vein of Dragonfly Wing in Its Configuration and Aerodynamic Behaviors

The microstructure of the main longitudinal veins of the dragonfly wing and the aerodynamic behaviors of the wing were investigated in this paper. The microstructure of longitudinal vein presents two circumferential chitin layers and a protein-fiber soft layer. The dragonfly wing is corrugated due to the spatial arrangement of longitudinal veins. It was found that the corru- gation angle could significantly influence the lift/drag ratio across a range of attack angles by the wind tunnel experiments. The results of the finite element analysis indicate that the protein soft layer of vein facilitates the change of the corrugation angle by allowing substantial relative twisting deformation between two neighboring veins, which is not possible in veins without a soft sandwich layer.

MODIFIED SZABO'S WAVE EQUATION FOR ARBITRARILY FREQUENCY-DEPENDENT VISCOUS DISSIPATION IN SOFT MATTER WITH APPLICATIONS TO 3D ULTRASONIC IMAGING

Soft matters are observed anomalous viscosity behaviors often characterized by a power law frequency dependent attenuation in acoustic wave propagation. Recent decades have witnessed a fast growing research on developing various models for such anomalous viscosity behaviors among which one of the present authors proposed the modified Szabo＇s wave equation via the positive fractional derivative. The purpose of this study is to apply the modified Szabo＇s wave equation to simulate a recent ultrasonic imaging technique called the clinical amplitude- velocity reconstruction imaging （CARI） of breast tumors which are of typical soft tissue matters. Investigations have been made on the effects of the size and position of tumors on the quality of ultrasonic medical imaging. It is observed from numerical results that the sound pressure along the reflecting line, which indicates the detection results, varies obviously with sizes and lateral positions of tumors, but remains almost the same for different axial positions.

Digital holography as metrology tool at micronanoscale for soft matter

The appearance of the first laser approximately 12 years after the invention of holography by Gabor(1948)revolutionized the field of optical metrology.In fact,the invention of holographic interferometry enabled the exploitation of interferometry on non-mirror surfaces and full-scale objects.The holography-based measurement methods has been implemented to several industrial systems or in support of R&D with the aim of improving new products in many fields(automotive,aerospace,electronics,etc.).To date,holography has been considered an important measurement tool for non-destructive inspection(NDI),strain-stress measurement,and vibration analysis at various engineering sites.Recently,the new paradigm of Industry4.0 has seen the introduction of new technologies and methods of processing materials as well as the development of manufacturing approaches for the realization of innovative products.For example,direct printing,additive,and bottom-up manufacturing processes are expected to involve new ways of making products in future,and most innovative fabrication processes will be based on the manipulation of soft matter(e.g.,starting from the liquid phase)that will be shaped at the nanoscale.The inherent characteristics of digital holography(DH)make it a powerful and accurate tool for the visualization and testing of final products,as well as for in situ and real-time monitoring and quantitative characterization of the processes involved during the fabrication cycle.This review aims to report on the most useful applications of soft matter,where the capabilities offered by DH,such as three-dimensional(3D)imaging,extended focus,3D tracking,full-field analysis,high sensitivity,and a wide range of measurements from nanometers to centimeters,permit completely non-invasive characterizations on a full-scale.Several holographic experimental results of typical samples are reported and discussed where DH plays a primary role as a tool gauge for soft matter.

Modelling drying pathways of an evaporating soft matter droplet

Micro-droplets of soft matter solutions have different morphologies upon drying,and can become wrinkled,buckled or cavitated particles.We investigate the morphology evolution of a drying soft matter droplet in this work:at the early stage of drying,wrinkling or cavitation instability can occur in the droplet,depending on the comparison between the critical wrinkling and cavitation pressure;at a later stage of drying,no wrinkles will appear if cavitation happens first,while cavitation can still occur if wrinkling happens first.A three-dimensional phase diagram in the space of elastic length,gel layer thickness and weight loss is provided to illustrate the drying pathways of a soft matter droplet.This diagram can help guide future fabrications of micro-particles with desired morphologies.

Special topic on soft matter science and technology

Soft matter, as first proposed by de Gennes in 1991, describes a broad range of molecular systems exhibiting a large response to small foreign stimuli. Typically, it includes colloidal particles, amphiphiles, liquid crystals, polymers and others. The term ＂soft＂ originates from the common macroscopic properties of these systems and differentiates them from conventional ＂hard＂ materials. Over the past decades, the field of ＂soft matter＂ has progressed tremendously. Today, it is a truly multidisciplinary research endeavor bridging physics with chemistry and life science. There are many research activities all over the world that are solely devoted to the field of soft matter. In turn, the in-depth understanding of soft matter has promoted our sci- ence and technology and helped shaping our civilization as it is now.

Identifying the viscoelastic properties of soft matter from the indentation response of a hard film-soft substrate system

The indentation technique is widely used in measuring the mechanical properties of soft matter at the microscale or nanoscale,but still faces challenges by these unique properties as well as the consequent strong surface adhesion, including the strong nonlinear effect, unclear judgment of the contact point, difficulties in estimating the contact area, and the risk of the indenter piercing the sample. Here we propose a two-step method to solve these problems: lay a hard film on a soft matter, and obtain the viscoelastic properties of this soft matter through the indentation response of this composite structure. We first establish a theoretical indentation model of the hard film-soft substrate system based on the theory of plates, elastic-viscoelastic correspondence principle and Boltzmann superposition principle. To verify the correctness of this method, we measure the mechanical properties of the methyl vinyl silicone rubber(MVSR) covered by a Cu nanofilm. Finally, we test the effectiveness and error sensitivity of this method with the finite element method(FEM). The results show that our method can accurately measure the mechanical properties of soft matter, while effectively circumventing the problems of the traditional indentation technique.

THEORY OF LC BIOMEMBRANE——A PROBE INTO SOFT CONDENSED MATTER PHYSICS

Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an example, this article expounds the current development trend of this new and promising branch of contemporary physics.

自组装生物分子软物质材料及其物理特性

自组装生物分子软物质材料是以生物分子或生物分子基元为构建单元,通过自组织过程形成的一类新型软物质材料.因其组成单元的生物特性和其中弱相互作用驱动组装的特征,这类材料通常具有高度生物相容性、可逆组装、动态响应和微结构可控性等优势,在生物医学、组织工程和柔性传感等领域中被广泛关注并得到了相关研发和应用.本文简要介绍自组装生物分子软物质材料的基本构建原理和物理特性,并以氨基酸、多肽分子等组装单元为例,对三类自组装生物分子软物质材料(纳米材料、凝胶材料和复合材料)的自组装分子机制、材料构建思路、力学特性和功能应用场景做了具体阐述.我们认为自组装生物分子软物质材料的研究,将从结构单元的发掘和相关特性的表征,向多功能性质定制与前端应用集成方向发展,从而研发出崭新的复合智能生物软物质材料,进一步促进其在生物医学、有机半导体和软体机器人等新兴领域中的应用.

从果冻到软物质——几种不同类型水凝胶的制备及性质探究

水凝胶作为软物质的成员之一,是一种具有三维网络结构的新型功能高分子材料,以其含水量高、溶胀快、生物相容性好、对外界刺激响应灵敏等性质而被广泛应用于不同领域。本项目从生活中常见的果冻零食、水精灵玩具出发,逐步深入到适宜3D打印的水凝胶、可变形的水凝胶、基于热刺激的记忆-遗忘型水凝胶,面向不同的受众群体分层次科普水凝胶的知识、体验不同类型水凝胶的制备及性质探究实验,深入浅出地阐释实验背后的化学原理,提升公众的化学素养。

从软物质到拓扑力学超材料

软物质是物理学、化学和生物学的重要研究对象。在软物质中,等静定系统恰好处在力学稳定和非稳定的边缘,展现出丰富的物理性质,普遍存在于自然界和工程领域,如颗粒物质、细胞骨架纤维和软体机器人等。等静定系统展现出独特的力学性能极化现象,一侧因力学软模而展现出柔软性,另一侧则在自应力作用下异常坚硬,这种奇特的表面性质具有拓扑稳定性,对材料内部缺陷及外部破坏不敏感,为力学材料的创新设计提供了新视角,催生了“软物质拓扑力学”这一前沿领域。文章基于软物质的基本概念,融合拓扑能带理论,聚焦于力学超材料,讨论了软物质拓扑力学的发展历程及最新研究进展。

Transition Between Solid-like and Liquid-like States in Soft Silica Suspensions

The influences of silica volume fraction, electrolyte concentration and pH value upon the stress dependence of elastic modulus G′and viscous modulus G″ were investigated. The results show that the suspension transforms from a liquid-like state to a solid-like state with increasing the volume fraction of silica. Such a solid-like state can be transformed back into a liquid-like state under the application of a larger stress. At the higher volume fraction, the larger critical stress is required to induce the transition from solid-like to liquid-like state. As the electrolyte concentration decreases or pH value increases, the inter-particle force increases, which causes the state transition to occur at a higher stress.

海相淤泥质固化土强度劣化规律试验研究

针对海相淤泥质软土中水泥搅拌桩成桩效果不佳的问题,选取天津地区某地铁工程施工现场海相淤泥质黏土,通过室内水泥土无侧限抗压强度试验,研究了可溶性盐和有机质含量对海相淤泥固化的无侧限抗压强度(UCS)的影响,并通过扫描电镜(SEM)和X射线衍射(XRD)对其微观结构和物相特征进行分析。结果表明:土壤水泥的强度随可溶性盐和有机质含量的增加而降低,其主要通过破坏和抑制水泥水化产物的形成,进而降低水化产物的胶凝性能,破坏了水泥土结构,导致强度降低。该研究结果对解释海相淤泥质软土固化效果不佳的现象具有重要的意义。

Stabilization effects of surplus soft clay with cement and GBF slag

Utilization of industrial waste and surplus construction soft clay as construction material was recommended, and many attempts at geotechnical waste utilization were undertaken. This study aimed at the application of cement and a kind of industrial wastes, i.e. granulated blast furnace slag, on stabilization of surplus soft clay. The results showed that the cement and slag can successfully stabilize Ariake clays even though this high organic clay fails to be stabilized by lime and cement. Addition of slag in cement for stabilization induces higher strength than cement alone for longer curing time. The application of the cement with slag is more suitable than cement alone for stabilization because of economical consideration.