Bicontinuous Structure Research Articles

Liquid Metal–Ionic Liquid Composite Gels for Soft, Mixed Electronic–Ionic Conductors

AbstractMixed electronic–ionic conductors with high flexibility and stretchability can serve as key materials in rapidly emerging applications such as soft electronics and soft robotics. The combined use of two functional liquid materials, ionic liquids (ILs) and liquid metals (LMs), is of significant interest in the development of highly deformable mixed conductors. In this study, composite gels embedded with both IL and LM are prepared for the first time using a Ga–In eutectic (eGaIn), 1‐ethyl‐3‐methyl imidazolium bis(trifluoromethanesulfonyl)amide, and poly(vinylidene fluoride‐co‐hexafluoropropylene) as the LM, IL, and polymer matrix, respectively. The composite gels exhibit low electronic conductivities of the order of 10−3 S cm−1. The addition of an optimal amount of Ni particles (NiPs) improve the electronic conductivity to ≈25 S cm−1 while retaining mechanical flexibility. The electronic conductivity is further enhanced upon elongation due to the reversible alignment and elongation of the LM in the gel matrix along the stretching direction. Owing to a bicontinuous structure composed of the IL‐based gel and metal component phases, the composite gels exhibit high ionic conductivity of the order of 10−3 S cm−1. This study demonstrates a rational approach for designing stretchable mixed conductors using ILs and Ga‐based LMs.

Hierarchically porous membranes with multiple channels: Fabrications in PVDF/PMMA/PLLA blend and enhanced separation performance

In this work, separation performance of hierarchically porous membranes (HPMs) with multiple channels have been investigated with the combination of finite element simulation and experiment. The simulation results indicate that in addition to m-channels (i.e., channels in microns) in reference (with only pores in microns), nanopores in HPMs not only contribute to n-channels (channels in nanometers), but also connect them with m-channels, producing mixed channels. In experiment, PVDF HPMs have been prepared in poly(vinylidene fluoride)/poly(methyl methacrylate)/poly(l-lactic acid) (PVDF/PMMA/PLLA) blend based on phase separation and crystallization templates. Phase separation produces bi-continuous structures of PLLA and PVDF/PMMA with size of microns. In the latter, PMMA has been expelled out during the crystallization of PVDF, resulting in the bi-continuous structures of them in nanometers. Upon etching with chloroform, both PLLA and PMMA have been removed, yielding pores in microns and nanometers respectively. Relative to reference, HPMs exhibit enhanced separation performance, which can be attributed to the shorter diffusion length, extra channels, enlarged contact angle difference and enhanced driving force for separation. Both simulation and experiment results indicate that multiple channels play more important role in the improvement of flux in the case of smaller m-channel diameter. Our results provide an efficient solution for trade-off effect in separation based on HPMs with multiple channels.

A study of electrocatalytic ethanol oxidation of nanoporous PtSi alloy

In recent years, nanoporous alloys have presented the advantages of a large specific surface area, low density, and simple operation, and they have been widely used in the fields of catalysis, magnetism, and medicine. Nanoporous Pt-Si alloy was prepared by melt-spun and chemical dealloying, and was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, and transmission electron microscopy. Pt-Si alloys possess a three-dimensional bicontinuous structure and an average size of 5 nanometers. Compared with commercial Pt/C catalysts, nanoporous Pt-Si alloys exhibit excellent electrocatalytic activity and stability in ethanol-catalyzed oxidation reactions. It is taken into consideration to be a promising catalyst in direct ethanol fuel cells.

Fabrication and Evaluation of Lidocaine Hydrochloride loaded Cubosomes

Topical delivery of local anaesthetic drugs such as Lidocaine HCl using carriers and novel nanotechnology can enhance effective drug permeation through the skin into deeper layers and exhibit desirable duration of action. The present study was aimed to formulate and evaluate Lidocaine HCl loaded cubosomes (LHLCs) for sustained therapeutic topical action. Cubosomes emanated as favourable means for the delivery of the drug. LHLCs were prepared by top-down technique using lipid and polymer. Eight formulations of LHLCs were prepared using different concentrations of glyceryl monooleate (GMO) and Poloxamer 407 (P-407). Local anaesthetics create loss of sensation in particular region of the body by inhibiting impulse generation and propagation. Lidocaine HCl is most commonly used amino amide local anaesthetic. It is used as local, topical, intravenous, epidural, peripheral and spinal anaesthesia. The prepared cubosomal dispersions were evaluated to determine surface morphology, particle size, poly dispersibility index (PDI), zeta potential, entrapment ability, tissue distribution studies, and in vitro drug release studies. Scanning Electron Microscopic analysis confirmed that drug was encapsulated in bicontinuous structure. The maximum entrapment efficiency was found to be 89.85±1.1% with vesicle size as 228±2.1nm, charge as -5.68±2.7, PDI as 0.295 and 98.83%± 0.12 in vitro drug release at the end of 12 hr for F7 formulation, which was confirmed as optimized cubosomal dispersion.

Dealloying Behavior in Ni-Cr-Fe Alloys As a Precursor to SCC in Boiling Caustic Environments

Experiments have shown that the susceptibility of Ni-Cr-Fe Alloys to dealloying, and subsequently stress corrosion cracking (SCC), highly depends on alloy composition and electrochemical potential. Dealloying is defined as the selective dissolution of the more active elements in an alloy (e.g., Cr and Fe in a Ni-based alloy). A dealloying process results in a remnant nano-porous layer on the surface that could be a precursor to SCC by a mechanism known as film-induced cleavage (FIC) where cracks propagate through this layer with sufficient velocity to promote energy transmission into the underlying metal resulting in cleavage fracture. Presence of a threshold amount of a more noble element could theoretically suppress this phenomenon by surface diffusion. This was investigated further by previous researchers, and the percolation theory of materials was hypothesized that states that the more noble element in an alloy creates a percolating mass that would limit the ability to retain a connected pathway of the reactive elements from the surface given it reaches a certain threshold of the mass of the material. This percentage was estimated to be between 50-60% for most alloying systems and termed the parting limit. In this study, percolation theory and dealloying is further explored by exposing several Ni-based and Fe-based alloys with varying percentages of Ni to boiling caustic solutions (50% NaOH) and evaluating their dealloying behavior.As mentioned, dealloying highly depends on electrochemical potential and is believed to occur above a threshold potential known as the dealloying critical potential. The dealloying critical potential is defined as the condition at which a transition occurs from a “passivated” alloy surface to the sustained formation of a bi-continuous porous structure. It can be identified by running an anodic polarization scan and initially matching anodic peaks to a pH-potential diagram (Pourbaix diagram) to evaluate the potential dissolution behavior. Bench-top electrochemical measurements were conducted to find the dealloying critical potential and make a correlation between this potential and alloys’ composition. The figure attached shows the anodic polarization scan results for all alloys included in the study in 50% NaOH at 140°C. It was observed that for the samples with high Ni content (i.e., Alloy 600 and Alloy 690) there was only a single active peak, which indicates transitioning to passivation and inhibition of dealloying. All other materials were susceptible to dealloying. Electron microscopy techniques were used to analyze all the samples used in the figure after exposure to 50% NaOH at 140°C at open circuit potential (OCP) and during a potentiostatic hold at the dealloying critical potential. Scanning electron microscopy (SEM) imaging followed by energy dispersive X-ray spectroscopy (EDS) revealed varying degrees of dealloying, with low Ni-containing alloys showing greater severity.The role of dealloying as a precursor to SCC was also evaluated by utilizing U-bend samples for Alloy 690, Alloy 800, and SS 304. The findings were in-line with previous dealloying result; the alloys with Ni content below the parting limit, SS304 and the Alloy 800, both underwent SCC after 48 hours of exposure to 50% NaOH solution at 135 °C, while the Alloy 690 sample (~60Ni) did not show any signs of cracking. A peculiar phenomenon was also noted for alloys containing Mo where it is seen that their dissolution current is approximately two folds higher than their counterparts with approximately the same Ni content. For example, when comparing SS 304 and SS 316 or Alloy C-276 and Alloy G-35. A possible explanation for that is the electrochemical behavior of Mo in caustic conditions where it is shown in its pourbaix diagram that dissolution occurs over a wider range of pH and potential in comparison to the other alloying elements. This earlier dissolution can possibly create more terrace sites on the surface that could accelerate the dissolution of iron and chromium. However, further studies are needed before a conclusion can be reached. Further work has also been conducted on Alloy 800 under the same conditions to evaluate the possibility of controlling the geometry of the dealloyed layer. The results so far indicate that the time of exposure and the electrochemical potential are critical in controlling the geometry of the dealloyed layer. Parallel studies are being conducted on SS 304 to evaluate the effect of Pb on extending the dealloying regime. The results so far have shown that the addition of Pb would shift the OCP more positively towards a region of passivity. It was also noted that dealloying kinetics is hindered in comparison to pure caustic conditions. However, SCC may still be possible with dissolved Pb present. Figure 1

SPIRE-a software tool for bicontinuous phase recognition: application for plastid cubic membranes.

Bicontinuous membranes in cell organelles epitomize nature’s ability to create complex functional nanostructures. Like their synthetic counterparts, these membranes are characterized by continuous membrane sheets draped onto topologically complex saddle-shaped surfaces with a periodic network-like structure. Their structure sizes, (around 50–500 nm), and fluid nature make transmission electron microscopy (TEM) the analysis method of choice to decipher their nanostructural features. Here we present a tool, Surface Projection Image Recognition Environment (SPIRE), to identify bicontinuous structures from TEM sections through interactive identification by comparison to mathematical “nodal surface” models. The prolamellar body (PLB) of plant etioplasts is a bicontinuous membrane structure with a key physiological role in chloroplast biogenesis. However, the determination of its spatial structural features has been held back by the lack of tools enabling the identification and quantitative analysis of symmetric membrane conformations. Using our SPIRE tool, we achieved a robust identification of the bicontinuous diamond surface as the dominant PLB geometry in angiosperm etioplasts in contrast to earlier long-standing assertions in the literature. Our data also provide insights into membrane storage capacities of PLBs with different volume proportions and hint at the limited role of a plastid ribosome localization directly inside the PLB grid for its proper functioning. This represents an important step in understanding their as yet elusive structure–function relationship.

Influence of hexadecylphosphocholine (Miltefosine) in phytantriol-based cubosomes: A structural investigation

Miltefosine (hexadecylphosphocholine, HePC) is a broad spectrum antimicrobial, anti-leishmanial drug, originally developed as anti-cancer agent. Because of its toxic side effects, several nanotechnology-based formulations have been considered as carriers for HePC. It is clear that the loading efficiency and bioavailability are strongly correlated to structural properties of the considered nanocarries. Therefore, the interplay between the structure stability and the entrapped compounds is worthy of investigation. In the present study, we evaluated the structural properties of phytantriol (PHY) cubosomes prepared in full hydrated conditions in the presence of increasing HePC concentrations. Dynamic Light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM) and small angle X-ray scattering (SAXS) were used. According to our data, HePC did not influence the nanoparticle average size at least up to 10 mol% HePC/PHY, even if the nanoparticle polydispersity index (PDI) increased by two-fold. On the other side, the nanoparticle inner structure shows a strong drug concentration dependence. Up to 3.5 mol%, the nanoparticles show a bicontinuous Pn3m Cubic internal structure, the lattice parameter of which increases as far as HePC is added to the system. The calculated structural data suggest that the HePC mixing with phytantriol induces a larger hydration capacity of the lipid polar surfaces. For HePC concentrations higher than 7.0 mol%, the internal structure of cubosomes is characterized by the coexistence of Pn3m and Im3m bicontinuous cubic phases, indicating that the swelling of the Pn3m phase arrived at saturation. The calculated number of water molecules per lipid in the cubic unit cell confirms such an indication. The structural parameters derived for the two cubic phases also indicate that HePC influence modify the negative Gaussian surface of the cubosomes.

Effects of pre-oxidation conditions on microstructure evolution and hydrogen evolution reaction performance of nano-porous Ag

A novel strategy was developed to fabricate nano-porous silver (NPS) with a three-dimensional bi-continuous open porous structure. A high temperature oxidation (HTO) craft and a strong oxidant-assisted low-temperature oxidation method were used to tune the dealloying of AgXCu(1-X) ribbons. The NPS fabricated from the Ag15Cu85 ribbon by the HTO pretreatment exhibited a ligament size of ∼841 nm after 1 h of dealloying. However, the NPS fabricated from the Ag15Cu85 ribbon by the H2O2 craft exhibited a ligament size of ∼61 nm after 1 h of dealloying. In addition, the NPS fabricated by the strong oxidant-assisted dealloying craft exhibited an ultrahomogeneous ligament pore structure and a higher Tafel slope in regard to its hydrogen evolution reaction.

Biphasic epoxy-ionic liquid structural electrolytes: minimising feature size through cure cycle and multifunctional block-copolymer addition

Structural electrolytes provide mechanical properties approaching structural resin combined with a high degree of ionic conductivity. Here, structural electrolytes based on bisphenol A diglycidyl ether and the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (EMIM-TFSI) were synthesised through reaction induced phase separation (RIPS) using isophorone diamine (iPDA) as a curing agent. The microstructure and properties of the resulting materials were controlled through both the initial formulations and the curing temperature. Curing at room temperature generated a bi-continuous structure and improved both mechanical performance and ionic conductivity of the resulting structural electrolytes. The balance between properties can be systematically adjusted; for example, a promising Young’s modulus of 800 MPa was obtained simultaneously with an ionic conductivity of 0.28 mS cm−1, for a formulation containing 35 vol% EMIM-TFSI. The lengthscale of the structural features was reduced by an order of magnitude by introducing multifunctional block-copolymers (MF-bcP) based on glycidyl methacrylate (GMA) and quaternised (2-dimethylamino)ethyl methacrylate (DMAEMA). Small angle neutron scattering (SANS), obtained during curing, identified at least two structural phases of different length scale, for the formulations containing MF-bcP, in agreement with microstructures observed using scanning electron microscopy. Such structural electrolytes may be required when using structural electrodes that also have finer characteristic lengthscales. The addition of the MF-bcP to formulations containing 35 vol% EMIM-TFSI produced structural electrolytes with a Young’s modulus of 530 MPa and an ionic conductivity of 0.64 mS cm−1.

A Novel Green Diluent for the Preparation of Poly(4-methyl-1-pentene) Membranes via a Thermally-Induced Phase Separation Method.

The use of green solvents satisfies safer chemical engineering practices and environmental security. Herein, myristic acid (MA)—a green diluent—was selected to prepare poly- (4-methyl-1-pentene) (PMP) membranes with bicontinuous porous structure via a thermally induced phase separation (TIPS) process to maintain a high gas permeability. Firstly, based on the Hansen solubility parameter ‘distance’, Ra, the effect of four natural fatty acids on the PMP membrane structure was compared and studied to determine the optimal green diluent, MA. The thermodynamic phase diagram of the PMP-MA system was calculated and presented to show that a liquid-liquid phase separation region could be found during the TIPS process and the monotectic point was around 34.89 wt%. Then, the effect of the PMP concentration on the morphologies and crystallization behavior was systematically investigated to determine a proper PMP concentration for the membrane preparation. Finally, PMP hollow fiber (HF) membranes were fabricated with a PMP concentration of 30 wt% for the membrane performance characterization. The resultant PMP HF membranes possessed good performances that the porosity was 70%, the tensile strength was 96 cN, and the nitrogen flux was 8.20 ± 0.10 mL·(bar·cm2·min)−1. We believe that this work can be a beneficial reference for people interested in the preparation of PMP membranes for medical applications.

Fast attenuation of high-frequency acoustic waves in bicontinuous nanoporous gold

We studied the formation and attenuation of GHz elastic waves in free-standing nanoporous gold films by MeV ultrafast electron diffraction and finite element simulations. By tracing the evolution of the high frequency acoustic waves in time domain, we found that the bicontinuous nanoporous structure in nanoporous gold films results in three-dimensionally acoustic response with low coherence, leading to fast attenuation of the elastic waves in comparison with solid gold films. The morphologically dominated dynamics indicates the nanoporosity plays an important role in the high-frequency acoustic energy relaxation, which shines a light on the applications of dealloyed nanoporous materials in nanodevices and sensors as GHz and THz acoustic filters and dampers.

Molecular insights on confined water in the nanochannels of self-assembled ionic liquid crystal.

Self-assembled ionic liquid crystals can transport water and ions via the periodic nanochannels, and these materials are promising candidates as water treatment membranes. Molecular insights on the water transport process are, however, less investigated because of computational difficulties of ionic soft matters and the self-assembly. Here we report specific behavior of water molecules in the nanochannels by using the self-consistent modeling combining density functional theory and molecular dynamics and the large-scale molecular dynamics calculation. The simulations clearly provide the one-dimensional (1D) and 3D-interconnected nanochannels of self-assembled columnar and bicontinuous structures, respectively, with the precise mesoscale order observed by x-ray diffraction measurement. Water molecules are then confined inside the nanochannels with the formation of hydrogen bonding network. The quantitative analyses of free energetics and anisotropic diffusivity reveal that, the mesoscale geometry of 1D nanodomain profits the nature of water transport via advantages of dissolution and diffusion mechanisms inside the ionic nanochannels.

Grain boundary formation through particle detachment during coarsening of nanoporous metals

Grain boundary formation during coarsening of nanoporous gold (NPG) is investigated wherein a nanocrystalline structure can form by particles detaching and reattaching to the structure. MicroLaue and electron backscatter diffraction measurements demonstrate that an in-grain orientation spread develops as NPG is coarsened. The volume fraction of the NPG sample is near the limit of bicontinuity, at which simulations predict that a bicontinuous structure begins to fragment into independent particles during coarsening. Phase-field simulations of coarsening using a computationally generated structure with a volume fraction near the limit of bicontinuity are used to model particle detachment rates. This model is tested by using the measured NPG structure as an initial condition in the phase-field simulations. We predict that up to ∼5% of the NPG structure detaches as a dealloyed [Formula: see text] sample is annealed at 300 °C for 420 min. The quantity of volume detached is found to be highly dependent on the volume fraction and volume fraction homogeneity of the nanostructure. As the void phase in the experiments cannot support independent particles, they must fall and reattach to the structure, a process that results in the formation of new grain boundaries. This particle reattachment process, along with other classic processes, leads to the formation of grain boundaries during coarsening in nanoporous metals. The formation of grain boundaries can impact a variety of applications, including mechanical strengthening; thus, the consideration and understanding of particle detachment phenomena are essential when studying nanoporous metals.

Significantly improved high dielectric MWCNTs filled PVDF/PS/HDPE composites via constructing double bi-continuous structure

Multi-layer composites with vastly difference in electrical properties for each layer are a promising candidate to design high dielectric materials, showing a tremendous promise on dielectric applications. But fabrication of these dielectric materials is relatively complicated, and unsuitable for large-scale production. Herein, a novel dielectric poly (vinylidene fluoride)/polystyrene/high density polyethylene (PVDF/PS/HDPE) composite constructed via tri-continuous structure were designed. And via variation PS concentration to control the compatibilizer effect of PS phase, a smaller PS phase size has been obtained and this composite finally exhibits a double bi-continuous morphology structure. For this double bi-continuous PVDF/PS/HDPE composite, a better dispersion of MWCNT particles increases the density of interfacial charge enrichment, and the increase of the specific surface area of the interfacial layer increases the number of enriched charges, which make the interfacial polarization increase most significantly compared with the other composites. Thus, a high-performance dielectric PVDF/PS/HDPE composite with high ε′ and low tan δ have been realized.

Nanoporous silver-modified LaCoO3-δ perovskite for oxygen reduction reaction

Substantial progress has been made in developing perovskite-based catalysts for oxygen reduction reaction (ORR). This article reported an ORR electrocatalyst composed of nanoporous Ag (NP-Ag) and LaCoO3-δ (LC) perovskite oxide and designed to take advantage of the bi-continuous NP structure and high electrocatalytic performance of perovskite oxides. The triple-phase boundaries (TPBs) formed by NP-Ag and LC provided active sites for the electrocatalytic reactions. Further annealing promoted the interaction between NP-Ag and LC, which induced the formation of more Co3+ and surface oxygen vacancies, as proved by multiple characterizations. When the mass ratio of LC and NP-Ag was 1:2 (LC/Ag-1/2-A), the catalyst showed the best ORR performance with a relatively high half-wave potential, and only attenuated by 4% after 5,000 cycles of accelerated durability testing. Besides, it delivered significant bifunctionality towards both ORR and OER, bearing comparison with the reported perovskite-based electrocatalysts. This work demonstrated a novel route for extending the application of NP metals and facilely designing efficient bifunctional electrocatalysts.

Formation of three-dimensional bicontinuous structures via molten salt dealloying studied in real-time by in situ synchrotron X-ray nano-tomography

Three-dimensional bicontinuous porous materials formed by dealloying contribute significantly to various applications including catalysis, sensor development and energy storage. This work studies a method of molten salt dealloying via real-time in situ synchrotron three-dimensional X-ray nano-tomography. Quantification of morphological parameters determined that long-range diffusion is the rate-determining step for the dealloying process. The subsequent coarsening rate was primarily surface diffusion controlled, with Rayleigh instability leading to ligament pinch-off and creating isolated bubbles in ligaments, while bulk diffusion leads to a slight densification. Chemical environments characterized by X-ray absorption near edge structure spectroscopic imaging show that molten salt dealloying prevents surface oxidation of the metal. In this work, gaining a fundamental mechanistic understanding of the molten salt dealloying process in forming porous structures provides a nontoxic, tunable dealloying technique and has important implications for molten salt corrosion processes, which is one of the major challenges in molten salt reactors and concentrated solar power plants.

Droplet-Bijel-Droplet Transition in Aqueous Two-Phase Systems Stabilized by Oppositely Charged Nanoparticles: A Simple Pathway to Fabricate Bijels.

We demonstrate a novel yet straightforward methodology of stabilizing aqueous two-phase systems (ATPS) using oppositely charged nanoparticles (OCNPs). We employ commercial-grade, Ludox, OCNPs to induce self-assembly. This self-assembly route promotes the stronger adsorption of nanoparticles at the water-water interface by triggering the formation of 2D and 3D aggregates of varying sizes and shapes. The interplay of this size and shape promotes stability due to increased Gibbs detachment energy and modulates the resulting cluster adsorption at the interface, thereby the structural state of emulsions. We demonstrate the influence of polymers' and particles' composition on the structural transformation from droplet-bijel-droplet using a phase diagram. For the first time, such a structural transition and the single pathway are reported within the domain of ATPS to produce stable bijels or colloidal capsules. It is asserted that the essential condition of three-phase contact angle (θ) = 90° to favor the formation of bijels can be established by selecting a suitable experimental condition using a phase diagram without employing any complicated surface modification procedures reported in the literature. Further, the mechanistic route favoring the formation of bijels and emulsion droplets at different experimental regimes is presented based on the empirical study using turbidity and zeta potential measurements. These studies reveal that the formation of bijels will be most favored when the parameter M (ratio of weight fraction of positively charged nanoparticles to negatively charged nanoparticles) is chosen between 0.7 and 4. It is intriguing to note the fact that, while the droplets stabilized by OCNPs have shown good resilience under high centrifugal action, the bijels produced in this way continued to remain stable for a long time, offering a facile route to prepare the bijels with a hierarchical bicontinuous network structure.

Communication—High-Temperature Electrochemical Synthesis of Nanoporous Iron by Dealloying of Ferromanganese in a LiCl-KCl Eutectic

A bi-continuous structure of nanoporous iron was synthesized by the high-temperature electrochemical dealloying of Fe0.5Mn0.5 in a molten LiCl-KCl eutectic. It was found that the characteristic bi-continuous structure of pores and ligaments of the order of 100 nm is formed at the lower temperature of 400 °C. At 500 °C another morphology of dendrite-like structure is formed since the number of ligaments decreases due to coarse-graining during processing. Surprisingly, at 600 °C, the formation of a new bi-continuous structure with “ginger-root-like” ligaments of several microns was observed.

In situ observation of liquid metal dealloying and etching of porous FeCr by X-ray tomography and X-ray diffraction

A liquid metal dealloying mechanism is investigated in situ using X-ray tomography and X-ray diffraction. While immersing a FeCrNi precursor alloy in a molten Mg bath, a selective dissolution of Ni atoms into the Mg bath occurs leading to FeCr atom rearrangement. At room temperature, after cooling down, a bicontinuous structure of FeCr and a solid solution of Ni in Mg is obtained. A final etching step is used to remove the Mg solid-state solution phase and form microporous FeCr. 3D dealloying and etching kinetics can be measured using X-ray tomography reconstruction. The evolution of relative strain is analyzed from X-ray diffraction patterns. The different behavior observed during dealloying and etching, depending on the precursor composition is discussed.

Polymerization‐Induced Self‐Assembly for the Preparation of Poly(N,N‐dimethylacrylamide)‐b‐Poly(4‐tert‐butoxystyrene‐co‐pentafluorostyrene) Particles with Inverse Bicontinuous Phases†

Main observation and conclusionPolymerization‐induced self‐assembly (PISA) is an effective method to prepare block copolymer (BCP) particles with various morphologies. However, BCPs with inverse bicontinuous phase structure have been rarely prepared via PISA. Herein, we report the preparation of particles, consisting of poly(N,N‐dimethylacrylamide‐b‐poly(4‐tert‐butoxystyrene‐co‐pentafluorostyrene) BCP, with inverse bicontinuous phases via PISA in ethanol/water. The effects of solvent composition and the degree of polymerization of the core‐forming were investigated. The bicontinuous structure of BCP particles was characterized by transmission electron microscopy.