Colloidal Probe Research Articles

Active microrheology of protein condensates using colloidal probe-AFM

Protein condensates resulting from liquid–liquid phase separation have long been studied as bio-adhesives and coating materials for various applications. More recently, they are also being scrutinized as models for membraneless organelles in cells. Quantifying their interfacial mechanics and rheology at micrometer scales is vital for better understanding the physics underlying membraneless organelles in cells and for developing and improving technological applications of protein condensates. This study demonstrates how colloidal probe atomic force microscopy with an oscillating tip can be used to simultaneously investigate the interfacial mechanics and dynamic rheological properties of micro-scale protein condensates, formed via carefully controlled capillary condensation. This new approach can access oscillation frequencies ranging from 1 to 104 rad/s. By analyzing the data using an equivalent mechanical model, three characteristic frequency domains for the mechanics of micro-scale protein condensates are found: an interfacial tension-dominated domain at low frequencies, a transition domain (viscous-to-elastic crossover) at intermediate frequencies, and an elasticity-dominated domain at high frequencies, covering a broad range of time scales relevant in biology and technological applications of protein condensates.

Intermolecular adhesion forces explain the formation of denitrifying granular sludge driven by acidic pH under ambient temperature

Denitrifying granular sludge (DGS), with a unique microbial structure and high biomass retention, is tolerant to harsh environments (e.g., toxic, acidic and high temperature); therefore, its cultivation is of increasing interest. In this study, we explored the feasibility of DGS cultivation under acidic pH using a sequencing batch reactor and elucidated the mechanism. By lowering the influent pH (from 7.0 to 5.0), the content of extracellular polymeric substances (EPS) increased from 29.28 to 114.80 mg∙g-1 VSS, promoting successful DGS cultivation (mean particle size 241 µm) with high activity (VSS/SS = 0.96) and a total nitrogen removal efficiency above 99 %. Microbial community analysis revealed that Thauera (38.52 %) might be the main producer of EPS. During granulation, the extracellular protein (PN) and exopolysaccharide (PS) content increased by 2.78 and 12.49 times, respectively, with PN always being dominant. Further studies using atomic force microscopy combined with PN colloidal probes showed that both the PN-PN and PN-PS adhesion forces increased with decreasing pH (9.0, 7.0 and 5.0), indicating that the increasing contents of both PN and PS had a positive effect on sludge cell aggregation. At the same time, the PN-PN intercalation forces were greater than the PN-PS intercalation forces, especially at pH 5.0, where the former was 2.34 times greater than the latter, thereby demonstrating the dominant role of PN in DGS formation. This information provides more direct evidence for the role of PN and PS in granule formation, and this study provides an alternative strategy for the direct treatment of acidic nitrate-containing wastewater.

Studies of probe tip materials by atomic force microscopy: a review.

As a tool that can test insulators' surface morphology and properties, the performance index of atomic force microscope (AFM) probes is the most critical factor in determining the resolution of microscopy, and the performance of probes varies in various modes and application requirements. This paper reviews the latest research results in metal, carbon nanotube, and colloidal probes and reviews their related methods and techniques, analyses the advantages and disadvantages of the improved probes compared with ordinary probes by comparing the differences in spatial resolution, sensitivity, imaging, and other performance aspects, and finally provides an outlook on the future development of AFM probes. This paper promotes the development of AFM probes in the direction of new probes and further promotes the broader and deeper application of scanning probe microscope (SPM).

Carbon nanodots calibrated fluorescent probe of QD@amphiphilic polyurethane for ratiometric detection of Hg (II)

Because of its strong toxicity to the ecosystem and human beings, mercury is regarded as one of the most hazardous heavy metals. Among various fluorescent sensors that have been designed for Hg (II) detection, the probes showing Hg (II) concentration dependent ratiometric fluorescent responses normally exhibited improved analytical performance. Herein, we have synthesized series of amphiphilic polyurethane (PU) to encapsulate hydrophobic fluorescent quantum dots (QD) via the emulsion confinement self-assembly, leading to generation of QD@PU colloids whose red emission can be selectively quenched by Hg (II) among other metal ions. In order to further improve the Hg (II) detection performance of QD@PU probe, the green emitting carbon nanodots (CD) were synthesized and conjugated with QD@PU, resulting to formation of CD-QD@PU colloidal probe showing ratiometric fluorescent response towards Hg (II), which finally contributed to an enhanced sensitivity and wider linear range for Hg (II) detection. More interestingly, both QD@PU and CD-QD@PU doped stretchable PU membranes still hold naked eye discrimination for Hg (II). Basically, the current work revealed a universal protocol to prepare fluorescent probe for Hg (II) detection using PU and low dimensional fluorescent nanoparticles as building blocks, which will open new way for design and fabrication of other advanced sensors and analytical devices. • An amphiphilic block copolymer of polyurethane (PU) were synthesized. • PU was used to encapsulate fluorescent quantum dots (QD) to obtain QD@PU colloids. • The fluorescence of QD@PU colloids can be selectively quenched by Hg (II). • Nitrogen and sulfur co-doped carbon nanodots (CD) was synthesized. • The CD-QD@PU probe allows specific detection of Hg (II) down to 10.5 nM.

Determination of the rate-dependent adhesion of polydimethylsiloxane using an atomic force microscope

A JKR (Johnson-Kendall-Roberts) formalism is used to extract the Young modulus, the contact radius, and the energy release rate simply from the retraction curve of a borosilicate glass colloidal probe from a polydimethylsiloxane (PDMS) surface using an atomic force microscope. PDMS samples ranged from perfectly elastic to those with incipient viscoelasticity. The dependence of the release rate energy with the crack speed is verified using a fracture mechanics-based method.

Using colloidal AFM probe technique and XDLVO theory to predict the transport of nanoplastics in porous media

The plastic concentration in terrestrial systems is orders of magnitude higher than that found in marine ecosystems, which has raised global concerns about their potential risk to agricultural sustainability. Previous research on the transport of nanoplastics in soil relied heavily on the qualitative prediction of the mean-field extended Derjaguin–Landau–Verwey–Overbeek theory (XDLVO), but direct and quantitative measurements of the interfacial forces between single nanoplastics and porous media are lacking. In this study, we conducted multiscale investigations ranging from column transport experiments to single particle measurements. The maximum effluent concentration (C/C0) of amino-modified nanoplastics (PS–NH2) was 0.94, whereas that of the carboxyl-modified nanoplastics (PS–COOH) was only 0.33, indicating PS-NH2 were more mobile than PS-COOH at different ionic strengths (1–50 mM) and pH values (5–9). This phenomenon was mainly attributed to the homogeneous aggregation of PS-COOH. In addition, the transport of PS-NH2 in the quartz sand column was inhibited with the increase of ionic strength and pH, and pH was the major factor governing their mobility. The transport of PS-COOH was inhibited with increasing ionic strength and decreasing pH. Hydrophilicity/hydrophobicity-mediated interactions and particle heterogeneity strongly interfered with interfacial forces, leading to the qualitative prediction of XDLVO, contrary to experimental observations. Through the combination of XDLVO and colloidal atomic force microscopy, accurate and quantitative interfacial forces can provide compelling insight into the fate of nanoparticles in the soil environment.

Insights and Applications of Composite Electroplating

Composite electroplating is the process of particle incorporation during the electrolytic deposition of metal. This process produces composite films consisting of a metallic matrix containing a dispersion of small particles. The advantages of composite electrodeposition over other coating methods are the uniformity of deposition even for complex shapes, the strong adhesion to the substrate, reduction of waste compared to dipping or spraying techniques, low levels of contamination, the ability to produce functionally-gradient material and to continuously process parts. In addition, this process avoids the problems associated with high temperature or vacuum processing.There are many contradictory experimental results in literature concerning the effects of the electrocodeposition process variables on particle incorporation. The effects of some of the process variables also vary for different particle-electrolyte combinations and cell configurations. Some of the reported contradictions are a direct consequence of incomparable hydrodynamics. The bulk of experimental electrocodeposition research has been conducted using a vertical parallel plate electrode set-up. In this configuration, the particles are maintained in suspension by either stirring the solution, vibrating a perforated plate at the bottom of the cell, bubbling gas, or pumping the suspension through the cell, all of which result in uncontrollable, and hence incomparable hydrodynamics. Other contradictions are due to the fact that the process parameters were evaluated only for a narrow range of experimental parameters and to differences in particle size and purity.This talk discusses the experimental results and mathematical modeling of electrocodeposition of particles in a metallic matrix. The effects of several key parameters, such as current density, particle loading, electrolyte composition, particle surface charge and polarity, on particle incorporation in electrodeposited composite coatings were studied and modeled. All experiments were done utilizing rotating disk electrodes over a wide range of experimental conditions in which the incorporation behavior changes appreciably, yielding reproducible data for better interpretation of process effects and modeling. These studies were combined with colloidal probe AFM experiments and process archeology using pulse plating which helped to understand the codeposition mechanism.

Sliding Friction and Superlubricity of Colloidal AFM Probes Coated by Tribo-Induced Graphitic Transfer Layers.

Colloidal probe atomic force microscopy (AFM) allows us to explore sliding friction phenomena in graphite contacts of nominal lateral size up to hundreds of nanometers. It is known that contact formation involves tribo-induced material transfer of graphite flakes from the graphitic substrate to the colloidal probe. In this context, sliding states with nearly vanishing friction, i.e., superlubricity, may set in. A comprehensive investigation of the transfer layer properties is mandatory to ascertain the origin of superlubricity. Here we explore the friction response of micrometric beads, of different size and pristine surface roughness, sliding on graphite under ambient conditions. We show that such tribosystems undergo a robust transition toward a low-adhesion, low-friction state dominated by mechanical interactions at one dominant tribo-induced nanocontact. Friction force spectroscopy reveals that the nanocontact can be superlubric or dissipative, in fact undergoing a load-driven transition from dissipative stick-slip to continuous superlubric sliding. This behavior is excellently described by the thermally activated, single-asperity Prandtl-Tomlinson model. Our results indicate that upon formation of the transfer layer, friction depends on the energy landscape experienced by the topographically highest tribo-induced nanoasperity. We consistently find larger dissipation when the tribo-induced nanoasperity is slid against surfaces with higher atomic corrugation than graphite, like MoS2 and WS2, in prototypical van der Waals layered heterojunctions.

Trapped-particle microrheology of active suspensions.

In microrheology, the local rheological properties, such as the viscoelasticity of a complex fluid, are inferred from the free or forced motion of embedded colloidal probe particles. Theoretical machinery developed for forced-probe microrheology of colloidal suspensions focused on either constant-force (CF) or constant-velocity (CV) probes, while in experiments, neither the force nor the kinematics of the probe is fixed. More importantly, the constraint of CF or CV introduces a difficulty in the meaningful quantification of the fluctuations of the probe due to a thermodynamic uncertainty relation. It is known that, for a Brownian particle trapped in a harmonic potential well, the product of the standard deviations of the trap force and the particle position is dkBT in d dimensions, with kBT being the thermal energy. As a result, if the force (position) is not allowed to fluctuate, the position (force) fluctuation becomes infinite. To allow the measurement of fluctuations in theoretical studies, in this work, we consider a microrheology model in which the embedded probe is dragged along by a moving harmonic potential so that both its position and the trap force are allowed to fluctuate. Starting from the full Smoluchowski equation governing the dynamics of N hard active Brownian particles, we derive a pair Smoluchowski equation describing the dynamics of the probe as it interacts with one bath particle by neglecting hydrodynamic interactions among particles in the dilute limit. From this, we determine the mean and the variance (i.e., fluctuation) of the probe position in terms of the pair probability distribution. We then characterize the behavior of the system in the limits of both weak and strong trap. By taking appropriate limits, we show that our generalized model can be reduced to the well-studied CF or CV microrheology models.

Advances in assembled micro- and nanoscale mechanical contact probes

The micro- and nanoscale characterization and mapping of surface properties and surface behaviour is critical to both physical and biological science. Mechanical contact probes are a critical tool for investigating surface and interface science, and have seen greater development and a diversification in recent years. In particular, mechanical contact probes that have been fabricated from the bottom-up by the assembly of synthesized nano- or microscale materials can provide enhanced functionality and sensitivity over traditional microcantilevers. This work provides an overview of recent developments in the field of assembled micro- and nanoscale mechanical contact probes, with a specific focus on three probe types: colloidal particle probes with high aspect ratio and a high lateral sensitivity, one-dimensional probes comprising of nanotube and/or nanowire deflection elements, and liquid metal-based probes. For each probe type, the state-of-the-art is reviewed, and their assembly, design, functionality and capabilities are discussed. An outlook on the future direction of probe development and potential applications is also given.

Effects of inorganic cations on the steric force between polyacrylamide layer physically adsorbed on SiO2 wafer and poly (ethylene oxide) layer

The physical adsorption of polyacrylamide on the SiO2 wafer in high salty solutions was investigated by an improved AFM steric force measurement. The colloid probe was modified by poly (ethylene oxide) layer and used to determine the steric force between adsorbed polyacrylamide and poly (ethylene oxide) layer in NaCl, KCl, MgCl2 and CaCl2 solutions. Assuming the adsorbed polyacrylamide complies with the self-similar model, the surface excesses, the thicknesses of the proximal regions, and "free energies of sticking" were estimated. Take the case of 5000 mg/L NaCl for example. The concentration profile was deduced from the corresponding steric force profile. The polyacrylamide concentration next to the SiO2 wafer was estimated to be about 147 g/L and the average concentration in the proximal region was estimated to be about 100 g/L. Based on the above estimations, interaction strength between the adsorbed cations and polyacrylamide was established, Mg2+ > Ca2+ > K+ > Na+. Moreover, the conformations of the adsorbed polyacrylamide were changed from "lying flat" to folded ones by the stronger interactions between the adsorbed cations and polyacrylamide.”

Forced microrheology of active colloids

Particle-tracking microrheology of dilute active (self-propelled) colloidal suspensions is studied by considering the external force required to maintain the steady motion of an immersed constant-velocity colloidal probe. If the probe speed is zero, the suspension microstructure is isotropic but exhibits a boundary accumulation of active bath particles at contact due to their self-propulsion. As the probe moves through the suspension, the microstructure is distorted from the nonequilibrium isotropic state, which allows us to define a microviscosity for the suspension using the Stokes drag law. For a slow probe, we show that active suspensions exhibit a swim-thinning behavior in which their microviscosity is gradually lowered from that of passive suspensions as the swim speed increases. When the probe speed is fast, the suspension activity is obscured by the rapid advection of the probe and the measured microviscosity is indistinguishable from that of passive suspensions. Generally for finite activity, the suspension exhibits a velocity-thinning behavior—though with a zero-velocity plateau lower than passive suspensions—as a function of the probe speed. These behaviors originate from the interplay between the suspension activity and the hard-sphere excluded-volume interaction between the probe and a bath particle.

Tuning the surface functionality of polyamide films via termination reaction in molecular layer-by-layer deposition

Molecular layer-by-layer (mLbL) deposition of highly crosslinked polyamide-based membranes affords flexibility and control over membrane properties such as thickness, roughness, and chemistry of the selective membrane layer. Of particular interest is the ability to non-destructively tailor the surface chemistry of the membrane for a particular purpose, such as enhancing hydrophilicity or minimizing membrane fouling. Here, we show that the surface chemistry of the mLbL membrane can be tuned via termination reactions to render the surface rich in –COOH, −NH2, −polyethylene glycol (−PEG), or −fluorinated groups. We systematically characterize the resulting surfaces with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) to validate successful modification and to ensure the low surface roughness is maintained, respectively. We then use pH-dependent contact angle and carboxylate-modified colloidal probe AFM to measure the surface wettability and adhesion of the modified surfaces. The measured adhesion force follows the ranking –NH2≫ −fluorinated > –COOH ≈ −PEG, where the –COOH and −PEG are repulsive due to charge interactions and hydration state, respectively. Combined with the low surface roughness afforded by mLbL deposition, surface functionalization through termination reactions as shown here will allow researchers to disentangle contributions of surface chemistry from surface roughness to the overall performance and fouling of polyamide-based membranes for water purification and advanced chemical separations.

Oscillatory structural forces probed by the nanofilm Macroscopic contact angle

The research on oscillatory structural forces (OSF) has a long history. OSF arise when liquid dispersions of a nano/micellar solution of complex fluids are confined between surfaces. In recent years, significant progress has been made in the measuring and modeling of OSF. Advanced techniques that use tools such as the surface forces apparatus (SFA), colloidal probe atomic force microscope (CP-AFM), and foam film capillary balance (FCB) were developed to gain information about nanofilm interactions in the confinement film geometry as the “layer” and “in-layer” particle entropy structural transition takes place. Henderson’s theory, based on the statistical mechanics approach to model the OSF, proposed analytical results using the Laplace transformation of the radial distribution function (RDF) for two large hard spheres in a fluid to calculate the film free energy; this approach is commonly applied to the model of the nanofilm layering between two solid surfaces. To extend Henderson’s theory to model the “layer” and “in-layer” structural transition of a capillary system, e.g., foam and emulsions, we propose the use of the foam film-meniscus macroscopic contact angle approach to calculate the nanofilm’s OSF.

Rapid and sensitive detection of metal chelator ethylenediamine tetraacetic acid

A colloidal gold-labeled monoclonal antibody nano-probe for metal chelator ethylenediamine tetraacetic acid (EDTA) was synthesized. Based on the probe, an immunochromatographic assay that was highly sensitive, convenient, and one-step competitive to detect EDTA, was developed. Then the immunochromatographic assay was applied for the detection of water samples. The goat anti-mouse IgG was immobilized on the nitrocellulose membrane as a control line. And the detection conjugate (isothiocyanobenzyl-EDTA-BSA) was immobilized on the nitrocellulose membrane as a detection line. EDTA in water samples would compete with the immobilized isothiocyanobenzyl-EDTA-BSA to bind with the colloidal gold probe. The visual detection limit of EDTA was detected to be about one ppm. The immunochromatographic assay in the present study does not need any equipment and complicated sample preparation and can be performed within 10 min. The EDTA concentrations in local water samples were successfully detected by the immunochromatographic assay, which is rapid, low cost, and suitable for testing on-site.

Absence of anomalous underscreening in highly concentrated aqueous electrolytes confined between smooth silica surfaces

Recent surface forces apparatus experiments that measured the forces between two mica surfaces and a series of subsequent theoretical studies suggest the occurrence of universal underscreening in highly concentrated electrolyte solutions. We performed a set of systematic Atomic Force Spectroscopy measurements for aqueous salt solutions in a concentration range from 1 mM to 5 M using chloride salts of various alkali metals as well as mixed concentrated salt solutions (involving both mono- and divalent cations and anions), that mimic concentrated brines typically encountered in geological formations. Experiments were carried out using flat substrates and submicrometer-sized colloidal probes made of smooth oxidized silicon immersed in salt solutions at pH values of 6 and 9 and temperatures of 25 °C and 45 °C. While strong repulsive forces were observed for the smallest tip-sample separations, none of the conditions explored displayed any indication of anomalous long range electrostatic forces as reported for mica surfaces. Instead, forces are universally dominated by attractive van der Waals interactions at tip-sample separations of ≈2 nm and beyond for salt concentrations of 1 M and higher. Complementary calculations based on classical density functional theory for the primitive model support these experimental observations and display a consistent decrease in screening length with increasing ion concentration.

Nonequilibrium fluctuations and nonlinear response of an active bath

We analyze the dynamics of a passive colloidal probe immersed in an active bath using an optical trap to study three physical processes: (1) the non-equilibrium fluctuations transferred to the probe by the active bath, (2) the friction experienced by the probe as it is driven through the active bath, and (3) the force relaxation of the probe returning to its equilibrium position. We measure the local force dynamics where all of the following characteristics are of $\mathcal{O}(1)$: the size of the probe colloid relative to active bath particle; the size of the probe colloid relative to the characteristic run-length of an active particle; and the timescale of probe movement to the persistence time of an active particle. We find at P\'{e}clet (Pe) $\ll 1$ the active suspension exhibits shear thinning down to the solvent viscosity (but not below); at $0.85 <$ Pe $\leq 5.1$ the active bath shear thickens; and at Pe $\geq 8.5$ the effective viscosity of the active bath shows a decreased effect of thickening and plateaus. These results are in agreement with recent modeling and simulations of the nonlinear rheology of an isotropic active bath, providing experimental verification, and suggesting the model predictions extends to moderately dense suspensions. Further, we observe that the distribution of force fluctuations depends on Pe, unlike in passive equilibrium baths. Lastly, we measure the energy transfer rate from the active bath to the probe to be $\langle J \rangle \approx 10^3$ $k_B T/$s, which leads to an increase in the effective diffusion of the probe by a factor of $\sim 2$.

Ionic liquids on uncharged and charged surfaces: In situ microstructures and nanofriction

In situ changes in the nanofriction and microstructures of ionic liquids (ILs) on uncharged and charged surfaces have been investigated using colloid probe atomic force microscopy (AFM) and molecular dynamic (MD) simulations. Two representative ILs, [BMIM][BF4] (BB) and [BMIM][PF6] (BP), containing a common cation, were selected for this study. The torsional resonance frequency was captured simultaneously when the nanoscale friction force was measured at a specified normal load; and it was regarded as a measure of the contact stiffness, reflecting in situ changes in the IL microstructures. A higher nanoscale friction force was observed on uncharged mica and highly oriented pyrolytic graphite (HOPG) surfaces when the normal load increased; additionally, a higher torsional resonance frequency was detected, revealing a higher contact stiffness and a more ordered IL layer. The nanofriction of ILs increased at charged HOPG surfaces as the bias voltage varied from 0 to 8 V or from 0 to —8 V. The simultaneously recorded torsional resonance frequency in the ILs increased with the positive or negative bias voltage, implying a stiffer IL layer and possibly more ordered ILs under these conditions. MD simulation reveals that the [BMIM]+ imidazolium ring lies parallel to the uncharged surfaces preferentially, resulting in a compact and ordered IL layer. This parallel “sleeping” structure is more pronounced with the surface charging of either sign, indicating more ordered ILs, thereby substantiating the AFM-detected stiffer IL layering on the charged surfaces. Our in situ observations of the changes in nanofriction and microstructures near the uncharged and charged surfaces may facilitate the development of IL-based applications, such as lubrication and electrochemical energy storage devices, including supercapacitors and batteries.

Investigating agglomeration of kaolinite particles in the presence of dodecylamine by force testing and molecular dynamics simulation

Kaolinite, one of the main components of clay minerals, is detrimental to slime water sedimentation. Sedimentation, adsorption, surface tension, contact angle, and interaction force measurements were conducted to study the hydrophobic agglomeration mechanism in kaolinite particles in the presence of dodecylamine (DDA). The results showed that DDA could be adsorbed on the kaolinite surface, improving the surface hydrophobicity and promoting hydrophobic particle agglomeration. Kaolinite hydrophobic sedimentation was enhanced with increased DDA concentration. The settling velocity and the adsorption of DDA on slurry particles were optimal when the DDA concentration was 14 × 10-4 mol/L. The shape and size distribution significantly affected the particle-surface interaction. Reliable force data could not be obtained from colloidal probes made of actual clay particles. Therefore, silica-silica and silica-alumina systems were used to replace clay mineral particles for force testing. AFM results showed that electrostatic repulsion existed in silica-silica and silica-alumina particles in ultrapure water. With DDA addition, the electrostatic repulsive force in silica-silica and silica-alumina particles decreased, the hydration film was destroyed, and an adhesion force was generated. In addition, the silicon-oxygen (001) surface of kaolinite adsorbed DDA more easily than the aluminum-oxygen (001̅) surface. The adsorption behavior of DDA+ on the kaolinite (001) and (001̅) surfaces was calculated by molecular dynamics simulation to explore the adsorption mechanism of DDA on kaolinite surfaces. The results suggested that the DDA+ polar head groups were adsorbed on the kaolinite surface, whereas the non-polar groups faced the solution. DDA+ adsorbed more easily on the (001) surface than on the (001̅) surface.

Tunable Adhesion and Interfacial Structure of Layer‐by‐Layer Assembled Block co‐polymer Micelle and Polyelectrolyte Coatings

AbstractUnderstanding and tuning nanoscale structure is critical in developing new coatings and adhesives. In this work layer‐by‐layer assembly of block co‐polymer (BCP) micelles and oppositely charged polyelectrolytes produces structurally unique coatings with wet adhesion comparable to that of mussel adhesive proteins. Cationic (CAT) and anionic (ANI) BCPs, synthesized by atom transfer radical polymerization (ATRP), are used to create colloidally stable, self‐assembled, spherical BCP micelles. The assembly of BCP micelle and polyelectrolyte multilayers is monitored in situ where CAT‐ and ANI‐BCP micelles exhibit linear and super‐linear growth, respectively. Imaging of the surfaces reveals that CAT‐BCP micelles yield flat, uniform layers whereas ANI‐BCP micelle assemblies form islands that increase in surface area with each additional layer. The adhesion of these layers, measured by colloidal probe atomic force microscopy (CP‐AFM), shows that the distinct layers of CAT‐BCP micelle assemblies produce alternating high and low adhesion surfaces whereas ANI‐BCP micelle assemblies continually increase in adhesion with each additional bilayer. The unique behavior of each assembly demonstrates that both composition and structure play important roles in wet adhesion of submicron layers and that each can be tuned to target performance for different applications.