Shear Flow Field Research Articles

Deformation of a ferrofluid droplet in a simple shear flow under the effect of a constant magnetic field

In the present work, we investigate the dynamics of a droplet of ferrofluid placed in a shear flow field subjected to the additional action produced by the application of a magnetic field in a direction perpendicular to the flow. The problem is solved in the framework of a moving-boundary method based on the solution of the Navier–Stokes equations complemented with the additional equations required for the determination of the magnetic force. The results reveal interesting changes in the trends displayed by the droplet deformation and inclination angle as a function of the capillary number when the intensity of the magnetic field is varied while maintaining flow conditions corresponding to the Stokes regime. The mechanism of droplet relaxation from equilibrium when the magnetic force is suddenly removed is also investigated. According to our numerical experiments the deformation evolves in time following a harmonic decaying process, which, in the limit of small capillary number, i.e. for very small deformations, can be fairly well represented by the temporal evolution of a simple damped harmonic oscillator.

Development of cellulose nanocrystal‐reinforced polylactide: A comparative study on different preparation methods

A masterbatch of polylactide (PLA) containing cellulose nanocrystals (CNCs) prepared via a solution‐cast method was further diluted with neat PLA in the melt state using either a twin‐screw extruder or an internal batch mixer to reach a final CNC content of 4 wt%. For the sake of comparison, a direct melt mixing method was employed to prepare PLA–CNC composites. Then, the efficiency of the preparation methods was assessed by comparing the morphological, rheological and thermomechanical properties of the compounded samples. Scanning electron microscopy showed the disappearance of large agglomerates when using the PLA–CNC masterbatch. Transmission electron microscopy revealed the existence of well‐dispersed CNCs within the PLA matrix at a nanoscale for masterbatch‐based nanocomposites. The rheological properties of the nanocomposites containing the PLA–CNC masterbatch were significantly increased for both steady and small‐amplitude oscillatory shear flow fields, compared to the composites prepared via direct melt mixing. In addition, the masterbatch‐based nanocomposites exhibited pronounced overshoots in the transient start‐up viscosity. The crystalline content of the PLA in the nanocomposites and the crystallization temperature increased when the CNCs were well dispersed, which showed the nucleating effect of the CNCs. In dynamic mechanical thermal analysis, the storage modulus of the nanocomposites increased up to 41 and 128% in the glassy and rubbery regions, respectively. These results show that hydrophilic CNCs can be well dispersed and reinforce PLA using efficient preparation methods. POLYM. COMPOS., 40:E342–E349, 2019. © 2017 Society of Plastics Engineers

The lift on a small sphere in a linear shear flow near the interface of two immiscible fluids

AbstractAnalytical expressions have been derived which predict, to lowest order, the inertial lift and the lateral migration velocity of a rigid sphere translating and rotating in a linear shear flow field near the flat interface of two immiscible fluids. This asymptotic analysis is primarily based on the assumption that the two Reynolds numbers defined by the gap width between the interface and the sphere, the shear rate and the translational slip velocity with which the spherical particle moves parallel to the interface are small. Furthermore, the radius of the sphere is assumed to be small compared to the gap width. To leading order in this creeping flow regime, the linear Stokes equations are obtained and a symmetry argument can be used to show that the Stokes solution does not predict any lift force. The transverse force experienced by the sphere and its migration velocity are due to the small but finite inertial terms in the Navier‐Stokes equations, which can be studied by perturbation techniques. By applying a Green's function approach and matched asymptotic methods, which also incorporate the effects of the outer Oseen‐like flow regime, the three components comprising the lift velocity have been calculated in closed form: the one induced by the shear rate only, the purely slip induced one and the one due to the interaction of the slip velocity with the shear flow field. The thus obtained expressions for the case of two immiscible fluids with arbitrary density and viscosity ratios extend the results that already exist in the literature for other flow configurations, such as an unbounded shear flow field [1] or a wall‐bounded one, where the wall lies either within the leading order Stokes region [2] or in the outer Oseen region [3]. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Ferrocholesteric-ferronematic transitions induced by shear flow and magnetic field.

We study the unwinding of the ferrocholesteric helical structure induced by a combined action of a magnetic field and a shear flow. Both influences are able to induce the ferrocholesteric–ferronematic transition independently; however, the differences between the magnetic field orientation and the flow alignment direction lead to a competition between magnetic and hydrodynamic mechanisms of influence on the ferrocholesteric structure. We analyze various orientations of a magnetic field relative to the direction of a shear flow. The pitch of the ferrocholesteric helix is obtained as function of the strength and the orientation angle of the magnetic field, the shear velocity gradient and a reactive parameter. Phase diagrams of ferrocholesteric–ferronematic transition and the pitch of the ferrocholesteric helix as functions of the material and the governing parameters are calculated. We find out that imposing a shear flow leads to a shift of the magnetic field threshold. The value of the critical magnetic field depends on the magnetic field orientation, the velocity gradient, and the viscous coefficients. We show that the interplay of a magnetic field and a shear flow can induce reentrant orientational transitions that are ferrocholesteric–ferronematic–ferrocholesteric.

Assessment of Dictyostelium discoideum Response to Acute Mechanical Stimulation.

Chemotaxis, or migration up a gradient of a chemoattractant, is the best understood mode of directed migration. Studies using social amoeba Dictyostelium discoideum revealed that a complex signal transduction network of parallel pathways amplifies the response to chemoattractants, and leads to biased actin polymerization and protrusion of a pseudopod in the direction of a gradient. In contrast, molecular mechanisms driving other types of directed migration, for example, due to exposure to shear flow or electric fields, are not known. Many regulators of chemotaxis exhibit localization at the leading or lagging edge of a migrating cell, as well as show transient changes in localization or activation following global stimulation with a chemoattractant. To understand the molecular mechanisms of other types of directed migration we developed a method that allows examination of cellular response to acute mechanical stimulation based on brief (2 - 5 s) exposure to shear flow. This stimulation can be delivered in a channel while imaging cells expressing fluorescently-labeled biosensors to examine individual cell behavior. Additionally, cell population can be stimulated in a plate, lysed, and immunoblotted using antibodies that recognize active versions of proteins of interest. By combining both assays, one can examine a wide array of molecules activated by changes in subcellular localization and/or phosphorylation. Using this method we determined that acute mechanical stimulation triggers activation of the chemotactic signal transduction and actin cytoskeleton networks. The ability to examine cellular responses to acute mechanical stimulation is important for understanding the initiating events necessary for shear flow-induced motility. This approach also provides a tool for studying the chemotactic signal transduction network without the confounding influence of the chemoattractant receptor.

Study on the morphology development and dispersion mechanism of polypropylene/graphene nanoplatelets composites for different shear field

Four different screw configurations were designed to prepare polypropylene (PP) nanocomposites reinforced with graphene nanoplatelets (GNPs). The relationship between the shear field, the morphology development of GNPs in PP and the properties of PP/GNPs nanocomposites were investigated. Finite element method software, POLYFLOW, was used to quantify the shear flow field in the four screw configurations. The morphology development was analyzed by field-emission SEM and optical transmission microscopy. The dispersion mechanism of GNPs in the PP matrix under the effect of a shear field was simulated showing that left-handed kneading elements resulted into the longest residence time and the addition of mixing elements resulted in the highest shear stress. Calculation results showed that during the extrusion process, large GNPs agglomerates (above 40 μm) tend to be exfoliated into smaller ones by two dispersion mechanisms corresponding to rupture and erosion. Since the shear stress provided by the twin-screw extruder configuration was limited, small agglomerates (below 40 μm) would exfoliate to thin layers only by following an erosion mechanism. The erosion mechanism and GNPs migration resulted to be mainly affected by the residence time. By increasing the residence time, nanocomposites resulted to be better dispersed and the particle size distribution was more homogeneous. Moreover, we found that the more the GNPs agglomerates thickness can be reduced by exfoliation, the more connection can established within the GNPs network, resulting in higher electrical and thermal conductivities.

Effect of the wall presence on the bubble interfacial forces in a shear flow field

Understanding the interactions between the bubbles and solid walls is important for predicting how the bubbly flow characteristics, such as void fraction and statistical distribution of bubble sizes, are affected by the presence of solid boundaries. In the present research, the numerical simulations with interface tracking method are performed to evaluate the interfacial forces’ closures in shear flow field under well-controlled conditions. The proportional-integral-derivative bubble controller is adopted to keep a single bubble at fixed position near the wall by balancing the forces in all three directions. This allows the extraction of the interfacial forces and the calculation of the corresponding coefficients. Validation tests have previously been conducted by the authors to compare the interfacial closures’ results against the experimental data. In this work, the influence of wall distance, relative velocity and bubble deformation on the interfacial forces are investigated. The results show that as the bubble approaches the wall, it experiences a transition from attractive force to repulsive force normal to the wall. The bubble Reynolds number also has significant impact on the interfacial forces: the net lateral force changes direction at Reb=35. The coupled phenomenon of bubble deformation and wall effect is investigated as well. The net lift sign change is observed at Eo=2.3 when the dimensionless wall distance (the ratio between the distance from the bubble center to the wall and the bubble diameter) is equal to 1. The presented studies complement the state-of-the-art knowledge and those are aimed to help improve the closure laws for interfacial forces and contribute to the multiphase computational fluid dynamics (M-CFD) closure model development.

Achieving high-efficiency and robust 3D thermally conductive while electrically insulating hybrid filler network with high orientation and ordered distribution

Continuous and robust filler network is very critical in improving thermal conductivity of the thermally conductive yet electrically insulating composite. Regrettably, such network is commonly constructed by large amount of thermally conductive while electrically insulating fillers with sacrificing mechanical properties of the final composite. In the present work, to address this issue and further improve the thermally conductive property, the robust 3D thermally conductive while electrically insulating hybrid filler network with high orientation and ordered distribution was constructed successfully through strong shear and extension flow field in confined space during the multilayer co-extrusion. In the hybrid filler network with the 32-layer alternating structure, along the extrusion direction, graphite (Gt) flakes were highly oriented; meanwhile, along the thickness direction, the local Gt-MWCNTs network was confined between two adjacent SiC-filled layers. As a result, thermal conductivity of the final composite reached as high as 2.05 W/(m × K). Furthermore, significantly anisotropic electrical resistivities were also obtained, which endowed the final composite with excellent electrical insulation, great anti-static and electromagnetic interference shielding properties. Moreover, compared with commonly compounded composites, mechanical properties of the multilayered composite were also enhanced significantly. As a consequence, the multifunctional composite with robust thermally conductive while electrically insulating filler network and excellent mechanical properties can be obtained based on this strategy, thus it plays a critical role in facilitating the development of the thermal management materials.

The chain scission extent of polystyrene in different shear flow fields

A mechanochemical reactor providing strong shear‐force has been developed in order to graft the polar groups onto the polymers. The extent of polymers' chain scission is a key factor in grafting process. In order to evaluate the scission extent, the shearing experiments were carried out for GPPS152P, which were produced by SECCO Petrochemical Company, Shanghai, China, at different revolving speeds, and temperatures. The decrease in molecular weight of GPPS152P was evaluated through gel permeation chromatography method and was estimated to be 13.8%. Additionally, the molecular weight distribution (MWD) of this sample became narrower. The chain scission theory and the shear rate, simulated through POLYFLOW software, were simultaneously employed to conduct quantitative analysis of molten PS' chain scission process. According to this method, the decrease in molecular weight was estimated to be 12.88%. Therefore, this method can be taken as a guideline for estimating molecular weight and MWD of products in manufacturing industry. POLYM. ENG. SCI., 58:913–919, 2018. © 2017 Society of Plastics Engineers

Simple and Consecutive Melt Extrusion Method to Fabricate Thermally Conductive Composites with Highly Oriented Boron Nitrides.

In the region of thermally conductive polymer composites, forcing anisotropic fillers into the highly oriented structure is the most effective method to improve thermal conductivity and mechanical properties simultaneously. However, up to now, such highly oriented structure was mainly achieved in low viscosity polymer matrix or solutions. For the purpose of expanding the range of applications, in the present work, a new strategy, the consecutive and powerful shear flow field, was applied to introduce highly oriented boron nitride (BN) into high viscosity polymer matrix. Results indicated that BN was almost totally oriented along the extrusion plane; as a result, the anisotropic index and thermal conductivity of the composite filled with 40 wt % BN reached as high as 480% and 3.57 W/(m K), respectively. Furthermore, compared with the samples with randomly oriented BN, elongations at break were improved more than 50-fold at the same filler content. Finite element analysis was also applied to systematically investigate the effect of the orientation direction of BN on heat dissipation property of the composites, and results indicated that orienting the longitudinal direction of BN parallel to the heat source is the best way to reduce the heat source temperature to a low level. Therefore, the simple, consecutive, and environmentally friendly melt extrusion with powerful shear flow field is an outstanding method to fabricate high efficiency thermally conductive composites, and the simulative results also have important significance on designing such composites for different applications.

Three-Dimensional Visualization and Characterization of Polymeric Self-Assemblies by Transmission Electron Microtomography.

Self-assembling structures and their dynamical processes in polymeric systems have been investigated using three-dimensional transmission electron microscopy (3D-TEM). Block copolymers (BCPs) self-assemble into nanoscale periodic structures called microphase-separated structures, a deep understanding of which is important for creating nanomaterials with superior physical properties, such as high-performance membranes with well-defined pore size and high-density data storage media. Because microphase-separated structures have become increasingly complicated with advances in precision polymerization, characterizing these complex morphologies is becoming increasingly difficult. Thus, microscopes capable of obtaining 3D images are required. In this article, we demonstrate that 3D-TEM is an essential tool for studying BCP nanostructures, especially those self-assembled during dynamical processes and under confined conditions. The first example is a dynamical process called order-order transitions (OOTs). Upon changing temperature or pressure or applying an external field, such as a shear flow or electric field, BCP nanostructures transform from one type of structure to another. The OOTs are examined by freezing the specimens in the middle of the OOT and then observing the boundary structures between the preexisting and newly formed nanostructures in three-dimensions. In an OOT between the bicontinuous double gyroid and hexagonally packed cylindrical structures, two different types of epitaxial phase transition paths are found. Interestingly, the paths depend on the direction of the OOT. The second example is BCP self-assemblies under confinement that have been examined by 3D-TEM. A variety of intriguing and very complicated 3D morphologies can be formed even from the BCPs that self-assemble into simple nanostructures, such as lamellar and cylindrical structures in the bulk (in free space). Although 3D-TEM is becoming more frequently used for detailed morphological investigations, it is generally used to study static nanostructures. Although OOTs are dynamical processes, the actual experiment is done in the static state, through a detailed morphological study of a snapshot taken during the OOT. Developing time-dependent nanoscale 3D imaging has become a hot topic. Here, the two main problems preventing the development of in situ electron tomography for polymer materials are addressed. First, the staining protocol often used to enhance contrast for electrons is replaced by a new contrast enhancement based on chemical differences between polymers. In this case, no staining is necessary. Second, a new 3D reconstruction algorithm allows us to obtain a high-contrast, quantitative 3D image from fewer projections than is required for the conventional algorithm to achieve similar contrast, reducing the number of projections and thus the electron beam dose. Combining these two new developments is expected to open new doors to 3D in situ real-time structural observation of polymer materials.

Inducing protein aggregation by extensional flow

Relative to other extrinsic factors, the effects of hydrodynamic flow fields on protein stability and conformation remain poorly understood. Flow-induced protein remodeling and/or aggregation is observed both in Nature and during the large-scale industrial manufacture of proteins. Despite its ubiquity, the relationships between the type and magnitude of hydrodynamic flow, a protein's structure and stability, and the resultant aggregation propensity are unclear. Here, we assess the effects of a defined and quantified flow field dominated by extensional flow on the aggregation of BSA, β2-microglobulin (β2m), granulocyte colony stimulating factor (G-CSF), and three monoclonal antibodies (mAbs). We show that the device induces protein aggregation after exposure to an extensional flow field for 0.36-1.8 ms, at concentrations as low as 0.5 mg mL-1 In addition, we reveal that the extent of aggregation depends on the applied strain rate and the concentration, structural scaffold, and sequence of the protein. Finally we demonstrate the in situ labeling of a buried cysteine residue in BSA during extensional stress. Together, these data indicate that an extensional flow readily unfolds thermodynamically and kinetically stable proteins, exposing previously sequestered sequences whose aggregation propensity determines the probability and extent of aggregation.

Thrombotic and hemolytic evaluation under shear flow field using a double-cylinder type rheometer

Thrombotic and hemolytic evaluation under shear flow field using a double-cylinder type rheometer

Improved viscoelastic, thermal, and mechanical properties of in situ microfibrillar polypropylene/polyamide 6,6 composites via direct extrusion using a triple-screw extruder

Improved viscoelastic, thermal, and mechanical properties ofin situmicrofibrillar polypropylene/polyamide 6,6 compositesviadirect extrusion using a triple-screw extruder.

대진폭 전단유동장에서 잔탄검 농후계의 비선형 점탄성 거동 연구: 응력파형 및 Lissajous 패턴 해석

The objective of the present study is to phenomenologically characterize the nonlinear rheological behavior of concentrated xanthan gum systems in large amplitude oscillatory shear (LAOS) flow fields by means of stress waveform and Lissajous pattern analysis. Using an Advanced Rheometric Expansion System (ARES), the dynamic viscoelastic behavior of aqueous xanthan gum solutions with different concentrations has been experimentally investigated in LAOS flow conditions with a various combination of several fixed strain amplitudes and constant angular frequencies. The main findings obtained from this study are summarized as follows: (1) When a sinusoidal deformation with large strain amplitude is applied, a distorted and nonsinusoidal but symmetrical stress response waveform is observed with time. (2) A saw-tooth shaped stress signal detected at large strain amplitudes may arise from a unique microstructure of xanthan polymer chains. A small peak of stress wave appearing at the position of maximum and minimum stress represents a nonlinear viscous nature of concentrated xanthan gum systems in LAOS flow fields. (3) As an increase in polymer concentration, the shape of stress wave becomes sharper and more distorted. This trend may be explained by an increase in structural density. (4) As a decrease in angular frequency, the stress wave exhibits a more distorted shape and both of the maximum and minimum peaks of a saw-tooth shaped stress response becomes more dominant. (5) At relatively small strain amplitudes, the Lissajous patterns (stress versus strain rate loops) show an elliptical form and their normalized ones are coincident with each other. When larger strain amplitudes are applied, however, the Lissajous patterns are noticeably nonelliptical, and moreover, as the strain amplitude is further increased, the tips of loops become more pointed with exhibiting a characteristic "S" shape.

The relationship between rheological behavior and microstructure of nanocomposite based on PA6/NBR/clay

Microstructure, rheological properties and their relationships of PA6/NBR/nano‐clay nanocomposite have been investigated. Scanning electron microscopy (SEM) and transmission electron microscopy imaging techniques were used to study micro‐structure. The nano‐clay dispersion was measured by small angle X‐ray diffraction. Frequency sweep, steady shear, startup shear transient, and startup shear free transient experiments were carried out to study rheological characteristics of nanocomposite. SEM micrograph revealed that nano‐clay decreased the size of rubber droplets to a half in comparison with samples without nano‐clay. Storage modulus of nanocomposite containing 7% wt nano‐clay exhibited frequency independent behavior because of physical network which formed in matrix, in contrast to pure PA6 which showed terminal storage modulus at low frequencies. Shear thinning at high shear rates was observed by addition of rubber to PA6 matrix caused by deformation of rubber droplets. Nano‐clay orientation in shear flow field accelerated non‐Newtonian behavior in steady shear experiment. Transient shear viscosity studies were used for measurement the strength of nano‐clay physical network. It was found that network breakdown is more stress consuming factor in comparison with nano‐particle orientation and hydrodynamic forces. Elongation transient viscosity studies showed that critical Hencky strain for linear–nonlinear viscoelastic transition shifted to higher strains by increasing nano‐clay concentration. POLYM. COMPOS., 39:2403–2410, 2018. © 2016 Society of Plastics Engineers

An investigation on the flow and heat transfer characteristics of nanofluids by nonequilibrium molecular dynamics simulations

ABSTRACTThe flow and heat transfer characteristics of nanofluids are investigated by nonequilibrium molecular dynamics simulations. Both the effect of chaotic movements of nanoparticle (CMN) on flow properties and its resulting heat transfer enhancement are analyzed. Results show that compared with the base fluid, the effective thermal conductivity of nanofluids is increased, and the increase ratio in the shear flow field is much higher than that in the zero-shear flow field. Based on the models built in this paper, the contributions of increased thermal conductivity and CMN to the heat transfer enhancement of nanofluids are 49.8–68.6% and 31.4–50.2%, respectively.

Reaction mechanism of blood coagulation factors in shear flow field.

Thrombus formation in blood pumps is a major problem. It has been reported that the shear rate is closely related to thrombus formation in blood pumps; however, the mechanism of blood coagulation in a shear flow field is not yet fully understood. The purpose of this study is to evaluate the effect of shear loading on the reaction of blood coagulation factors quantitatively. Human blood and porcine blood were used as test blood and sheared at 2,880 s-1 for 3 h using a rheometer. After shear loading to the test blood, the activated partial thromboplastin time (APTT) and prothrombin time (PT) of sample plasma were measured using an automated coagulation analyzer. The APTT and PT of mixed plasma containing human blood coagulation factor-deficient plasma and sample plasma were also measured. The APTT and PT of mixed plasma reflected the reaction of the particular blood coagulation factor. Results show that shear loading prolonged the APTT and PT of human sample plasma. Accordingly, the APTT and PT of mixed plasma containing human blood coagulation factor V-deficient plasma and human sample plasma were prolonged after shear loading. Thus, the reaction of human blood coagulation factors was inhibited by specific inhibition of the reaction of human blood coagulation factor V in the shear flow field. The reaction time of porcine blood coagulation factors after shear loading differed from that of human blood coagulation factors. The result suggest the evaluation difficulty of animal blood coagulation reaction, that is, porcine blood coagulation reaction did not fully proceed with clinical reagents due to species specificity.

A simulation-based analysis of the effect of a reflecting surface on aeroacoustic time-reversal source characterization and comparison with beamforming

This paper presents a simulation-based analysis of the effect of a reflecting surface on aeroacoustic Time-Reversal (TR) source localization/characterization and compares the results of TR with those obtained using cross-spectral Conventional Beamforming (CB). The TR technique is shown to require the use of at least two line arrays of microphones to accurately characterize the nature of aeroacoustic sources. This work, however, shows that in the presence of a rigid surface, only one line array of microphones is sufficient to accurately localize and characterize idealized aeroacoustic sources. Forward simulations were carried out using the 2-D Linearized Euler Equations on a rectangular domain with a rigid bottom boundary (modeling a 2-D semi-infinite space) for the test-cases of stationary idealized tonal aeroacoustic (monopole, dipole and lateral quadrupole) sources located in a fully-developed mean shear flow field wherein the acoustic pressure time–history was stored at the computational boundaries. A set of TR simulations are implemented that show for each test-case that only the top line array is required to accurately characterize the idealized aeroacoustic sources in the presence of a reflecting bottom boundary, thereby suggesting the redundancy of acoustic pressure measurement at the rigid surface. The test-case of convecting (moving) idealized aeroacoustic source was also considered and the TR simulation using only the top line array in the presence of reflecting bottom boundary was able to accurately retrieve the source trajectory and simultaneously characterize its nature. This numerical experiment demonstrates in principle that when a rigid surface is mounted on the floor of an Anechoic Wind Tunnel, the use of only one (top) line array of microphones should be sufficient to characterize the nature and location of experimental flow-induced noise source. Acoustic source maps were also obtained using the CB method based on the Method of Images (to model the reflecting surface) and incorporation of the Ray-Tracing algorithm necessary to account for the effect of mean flow. The CB results were found to be highly comparable to those obtained using TR for the test-cases of non-convecting sources; thereby demonstrating the conceptual equivalence of the Method of Images and directly implementing the rigid-wall condition during TR for source localization/characterization.

Robust Interfacial Cylindrites of Polylactic Acid Modulated by an Intense Shear Flow Field

Evolution of crystalline morphology/structure of PLA was investigated by combination of homemade fiber-pulling device and polarized optical microscopy, where the intense shear field within the range of the actual processing conditions was modulated by the pulling speed of glass fiber (GF). Sporadic dispersion of PLA spherulites in the quiescent melt indicated no nucleation ability of GF. High density of row-nuclei was induced by the strong shear flow (120 s–1) around the pulled GF surface. Also, these nuclei hindered the lateral extension of lamellae and forced growth direction perpendicular to the GF axis, leading to the formation of the semicircle cylindrite. As the shear rate rose to 280 and 420 s–1, nuclei density on the surface of pulled GF was further increased, and the cylindrites became more compact, generating the fan-shaped and brush-like morphology, respectively. As detected by two-dimension wide-angle X-ray diffraction, the cylindrites showed increased crystallinity and degree of orientation with the shear rate. Thereupon, the remarkable enhancement in the interfacial strength between the PLA matrix and GF was obtained, showing the upmost increase of 143% for the sheared sample (420 s–1) compared to the quiescent counterpart. These interesting results are of importance to bridge the gap between the crystalline morphology/structure of PLA and the shear flow quantitatively, offering helpful guidance to design the interfacial crystalline structure of PLA composites during the pratical processing.