Pore-filling Process Research Articles

Pore-scale investigation of forced imbibition in porous rocks through interface curvature and pore topology analysis

Forced imbibition, the invasion of a wetting fluid into porous rocks, plays an important role in the effective exploitation of hydrocarbon resources and the geological sequestration of carbon dioxide. However, the interface dynamics influenced by complex topology commonly leads to non-wetting fluid trapping. Particularly, the underlying mechanisms under viscously unfavorable conditions remain unclear. This study employs a direct numerical simulation method to simulate forced imbibition through the reconstructed digital rocks of sandstone. The interface dynamics and fluid–fluid interactions are investigated through transient simulations, while the pore topology metrics are introduced to analyze the impact on steady-state residual fluid distribution obtained by a pseudo-transient scheme. The results show that the cooperative pore-filling process promoted by corner flow is dominant at low capillary numbers. This leads to unstable inlet pressure, mass flow, and interface curvature, which correspond to complicated interface dynamics and higher residual fluid saturation. During forced imbibition, the interface curvature gradually increases, with the pore-filling mechanisms involving the cooperation of main terminal meniscus movement and arc menisci filling. Complex topology with small diameter pores may result in the destabilization of interface curvature. The residual fluid saturation is negatively correlated with porosity and pore throat size, and positively correlated with tortuosity and aspect ratio. A large mean coordination number characterizing global connectivity promotes imbibition. However, high connectivity characterized by the standardized Euler number corresponding to small pores is associated with a high probability of non-wetting fluid trapping.

Multi-technique investigation on the surface interaction of diatomaceous earth with organic phase change material: Experimental and molecular dynamics aspects

To promote diatomaceous earth (DE)-based phase change composite as green energy building materials, this paper bridges the studies of experimental and molecular dynamics (MD) focusing on the absorption effect of phase change materials (PCMs). Octadecanoic acid (OA) was selected as PCMs and DE as supporting material for the fabrication of composite PCMs at different loading ratios; effect on thermal properties and porosity of the composite PCMs were further investigated by MD simulation. In consonance with ATR-FTIR and XRD analyses, the highest loading ratio (DEOA-4) was proven to absorb a high amount of PCMs, with excellent thermal stability and chemical compatibility. DEOA-4 exhibited higher latent heat storage capacity of 52.67 J/g, with a loading ratio and loading efficiency of 32.13 and 32.98 %. Besides, MD simulation showed that increasing the OA loading would decrease the fractional free volume of DEOA models, resulting in a limited mobility of PCMs molecules, as confirmed by self-diffusion coefficient at room and melting temperatures. Experimental and computational studies revealed that pore-filling process plays an imperative role during PCMs absorption. An adequate amount of loading ratio can potentially enhance the pore-filling process, maximize the efficiency of the performances, and promote the development of green energy in concrete structures.

A novel porous asymmetric cation exchange membrane with thin selective layer for efficient electrodialysis desalination

Ion exchange membranes (IEMs) are widely used in various electrochemical fields. Generally, identifying a solution for the trade-off between ion conductivity and dimensional stability is crucial for the further development of IEMs in the electrodialysis (ED) process. This study aimed to prepare a novel type of cation exchange membrane for electrodialysis desalination. Different from the previous cation exchange membranes with the thick and dense cross-section structure, the as-prepared asymmetric composite membranes in the present work composed of a thin and dense skin layer and a porous support layer via the pore-filling process of the skin layer of the porous poly (ether sulfone) (PES) membrane. Benefiting from such structural features, effective ion transport and dimensional stability were simultaneously achieved in the case of low ion exchange capacity. Ultimately, the optimal sulfonated poly (ether sulfone)-poly (ether sulfone) (SPES-PES) composite membrane simultaneously achieved ion transport enhancement, low swelling rate at 80 °C, and better mechanical stability compared to pure sulfonated poly (ether sulfone) (SPES) membranes. When applied to ED, the prepared 40 %SPES-PES membrane exhibited more excellent desalination performance (91.9%), higher current efficiency (127.5%), and lower energy loss (5.55 Kw·h·kg−1) compared to commercial membrane.

Gyroid-structured nanoporous chitosan from block copolymer template for UVC reflection

Bioinspired from structural coloration of butterfly wing structure, this work aims to fabricate nanoporous chitosan for UVC reflection. By taking advantage of self-assembled polystyrene-b-polydimethylsiloxane (PS-b-PDMS) with double gyroid texture followed by hydrofluoric acid etching of PDMS block, nanoporous PS with well-defined nanochannels can be fabricated, and used as a template for templated crosslinking reaction of chitosan through a multiple pore-filling process. Well-ordered nanoporous chitosan with shifting networks in nanoscale can be successfully fabricated after removal of the PS template. With the low absorption of chitosan in the ultraviolet region and the shifting networks for opening the bandgap, it is appealing to exploit the nanonetwork chitosan as high reflective materials for UVC optical devices, as evidenced by finite-difference time-domain (FDTD) simulation and optical measurements experimentally.

Removal of Tetracycline from aqueous solution using composite adsorbent of ZnAl layered double hydroxide and bagasse biochar

A new composite adsorbent of biochar derived from bagasse and ZnAl-layered double hydroxide was produced by the in-situ growth method. The prepared biochars were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, the Brunauer–Emmett–Teller (BET) isotherms, Scanning electron microscopy (SEM), Energy Disperse X-ray (EDX) spectroscopic and Mular–Roberts titration analyses. The best Zn:Al molar ratio for the ZnAl-LDH/BGC composite to adsorb tetracycline was 3:1. The specific surface area of ZnAl-LDH/BGC31 was 456.39 m 2 /g compared to 404.05 m 2 /g for BGC. The optimal pH, contact time and initial TC concentration for TC adsorption were 6.0, 120 min and 25 mg/L, respectively. The ZnAl-LDH/BGC31 had a maximum adsorption capacity ( q m ) of 41.98 mg/g. The obtained data were analyzed with Langmuir, Freundlich and Tempkin isotherm models. Kinetic data were evaluated by using pseudo-first and pseudo-second-order kinetic models. The adsorption mechanism of ZnAl-LDH/BGC31 to remove TC was likely based on the pore-filling process, electrostatic attraction and π − π conjugate effect. ZnAl-LDH/BGC31 had significant adsorption capacity after five reusabilities. • ZnAl-layered double hydroxide bagasse biochar compositered (ZnAl-LDH/BGC31) was synthesized. • The maximum adsorption capacity ( q m ) of TC (41.98 mg/g) at pH 6 and 25 mg/L of initial TC. • Isotherm and kinetic model fitting indicated physisorption and chemisorption of TC. • The pore-filling process, electrostatic attraction and π − π conjugate effect were critical role in TC adsorption. • ZnAl-LDH/BGC31 adsorbent maintained its high adsorption ability up to 5 reusability.

Lithiation Pathway Mechanism of Si-C Composite Anode Revealed by the Role of Nanopore usingIn SituLithiation

Lithiation kinetics of a Si-C composite anode for high-capacity lithium (Li)-ion batteries were investigated through in situ lithiation and electrochemical C–V measurements using a focused ion beam (FIB). Here, we found in the lithiation procedure that Li migrates sequentially into carbon (C), nanopores, and silicon (Si) in the Si-C composite. In the first lithiation step, Li was intercalated inside C particles while spreading over the surface of the C particles. The second lithiation process occurred through the filling of nanopores existing between electrode particles that consisted of the Si-C composite. The nanopores acted as a Li reservoir during the pore-filling process. Finally, the Si particles were lithiated with a volume expansion of ∼70%, corresponding to a 300% volume expansion of 25 wt % Si particles included in the composite anode. The nanopores did not accommodate a large volume expansion of Si particles, because pore-filling lithiation occurred before the Si lithiation in the charging process. We suggest a design rule related to the role of the nanopores of the Si-C composite anode in LIB systems.

Elucidating in-Situ Lithiation Pathway of Si-C Composite Anode in Lithium Ion Battery

Lithiation kinetics of a Si-C composite anode for high-capacity lithium-ion batteries were investigated through in-situ lithiation with electrochemical C-V measurements using a focused ion beam. Here, we found in the lithiation procedure that Li migrates sequentially into carbon (C), nanopores, and silicon (Si) in the Si-C composite. In the first lithiation step, Li was intercalated inside C particles while spreading over the surface of the C particles. The second lithiation process occurred through the filling of nanopores existing between electrode particles that consisted of the Si-C composite. The nanopores acted as a Li reservoir during the pore-filling process. Finally, the Si particles were litheated with a volume expansion of 173%, corresponding to a 400% volume expansion of 25wt.% Si particles included in the composite anode. The nanopores did not accommodate a large volume expansion of ~400% in Si particles, because pore-filling lithiation occurred before the Si lithiation in the charging process.

Fluorine-Doped Hard Carbon as the Advanced Performance Anode Material of Sodium-Ion Batteries

F-doping hard carbon (F–HC) was synthesized through a mild fluorination at temperature at relative low temperature as the potential anode for sodium-ion batteries (SIBs). The F-doping treatment to HC expands interlayer distance and creates some defects in the graphitic framework, which has the ability to improve Na+ storage capability through the intercalation and pore-filling process a simultaneously. In addition, the electrically conductive semi-ionic C–F bond in F–HC that can be adjusted by the fluorination temperature facilitates electron transport throughout the electrode. Therefore, F–HC exhibits higher specific capability and better cycling stability than pristine HC. Particularly, F–HC fluorinated at 100 °C (F–HC100) delivers the reversible capability of 343 mAh/g at 50 mAh/g, with the Coulombic efficiency of 78.13%, and the capacity retention remains as 95.81% after 100 cycles. Moreover, the specific capacity of F–HC100 returns to 340 mAh/g after the rate capability test demonstrates its stability even at high current density. The enhanced specific capacity of F–HC, especially at low-voltage region, has the great potential as the anode of SIBs with high energy density.

Spent mushroom substrate is capable of physisorption-chemisorption of CO2

No in-depth investigation exists on the feasibility of integrating hydrothermal carbonization (HTC) and pelletization into the process of making spent mushroom substrate (SMS), an agro-food residue from the commercial mushroom industry, into an adsorbent for post-combustion CO2 removal. Therefore, this study analyzed if it could be possible for systematically converting low-pressure hydrochars of various SMSs into carbon-adsorbing mini-capsules. Sources of SMS included paddy straw and achiote capsule shell from Pleurotus ostreatus; eucalyptus sawdust and grassy straw from Lentinula edodes; and compost containing peat or soil as casing layer from Agaricus subrufescens. The eucalyptus sawdust and grassy straw from L. edodes outperformed the other biomaterials in adsorbing CO2, and thus effectively encapsuled most of the gas, 8.25 mmol g−1 and 8.10 mmol g−1, respectively. They contained mostly hetero-atoms of O and N, requiring less unit energy to bind acidic molecules of CO2 at the alkaline sites. The amount of unit energy the pore-filling process demanded at 25 °C was 12.65 kJ mol−1, an attribute of self-sustaining and saleable physisorption. A negative 6.80 kJ mol−1 free energy validated both spontaneity and exothermal of biocarbons at steady-state atmosphere. The major findings and innovations of our study support utilizing SMS as an adsorbent as a carbon capture, storage and utilization networking. Our insights into the physisorption-chemisorption on SMS are timely and relevant to help manage the re-use of SMS, and thus bring the global mushroom industry closer to environmental sustainability and toward a lower carbon society and circular economy.

Evolution of Jurassic intertrap deposits in the Parnaíba Basin, northern Brazil: The last sediment-lava interaction linked to the CAMP in West Gondwana

The opening of the Central Atlantic Ocean was accompanied by ascending plume zones that generated large igneous provinces (LIPs), such as the Central Atlantic Magmatic Province (CAMP), with voluminous lava flows and outpourings. One of the best records of the CAMP in the West Gondwana is the Jurassic volcanic-sedimentary succession exposed in the western Parnaíba Basin, northern Brazil. Diagenetic and hydrothermal processes are discussed, focusing on the lava-sediment interaction. The siliciclastic sediments called “intertrap deposits” record a wet desert system characterized by fluvial-aeolian and shallow lake deposits engulfed by lavas of the CAMP at approximately 200–202 Ma. The facies and petrographic studies, based on a drill core and outcrops, led to the interpretation of the palaeoenvironmental and diagenetic evolution of the intertrap deposits. The intertrap deposits are sandwiched by basalts and may be organized in seven sedimentary facies, grouped into two facies associations: 1) ephemeral braided river deposits (FA1), which consist of medium- to coarse-grained pebbly sandstone with poorly sorted angular to sub-rounded grains (basaltic fragments and quartz) and low-angle cross-bedding, even-parallel stratification, and trough cross-stratification, and 2) pond/shallow lake deposits (FA2) composed of tabular beds of sandstone/siltstone rhythmite and laminated mudstone. The main architectural elements of intertrap deposits are 1) channels on volcanic substrate, 2) sand sheets deposited over pre-existent lava topography, 3) tabular beds with laminated rhythmites, and 4) sand-filled fissures/fractures and clastic dykes. The intensification of magmatic processes due to the disruption of Pangaea promoted the formation of extensive volcanic plains, whereas wet desert settings were developed during the quiescent intervals between lava flow episodes. Fluvial channels with subaqueous dunes and sand sheets were incised into the basaltic substrate. The abandoned fluvial plains were affected by flash floods that promoted mechanical infiltration of clays, forming coatings over grains. The heat flow and hydrothermal activity of volcanic rocks increased the devitrification of glassy clasts, releasing silica and precipitating low-temperature authigenic mineral assemblages. The most common pore-filling process was the massive precipitation of early diagenetic-hydrothermal minerals, including smectite, chalcedony, poikilotopic zeolite, megaquartz, and haematite, which partially obliterated the primary porosity and permeability. These exceptional conditions of cementation triggered by basalt eruptions precluded the modification of a primary framework by late stages (post-Jurassic) burial diagenesis. The intertrap sandstones represent the last lava-sediment interaction related to the CAMP recorded in West Gondwana.

Effect of Porous Carbon Morphologies and Composite Manufacturing Processes on Long-Cycling Performance in High Sulfur Loading Li–S Batteries

Abstract Long-cycling performance of Li–S batteries was studied with the high-sulfur loading composites composed of 86% sulfur and 14% carbon. The composites are made by the physical mixing and S-liquefied pore-filling processes with nano sulfur powder and two kinds of porous carbons. The initial discharge capacities of the composite prepared by the physical mixing and liquefied pore-filling with 1-μm-sized carbon were 1060 mAh/g and 1121 mAh/g, respectively. On the other hand, the capacities of the composite using 5-μm-sized carbon were 705 mAh/g in physical mixing and 845 mAh/g in the liquefied pore-filling process. The composite with the 1-μm carbon showed approximately ∼1.4 times higher than that of 5 μm. The reason for this difference is that the surface area of the sulfur wrapping the small particle carbon surface is larger than that of the composite wrapping the large particle carbon surface. Importantly, after 500 cycles, the cycle stability in the physical mixing process is 15∼30% higher than that in the S-liquefied pore-filling process in both carbons, due to the decrease of electrolyte resistance by capturing polysulfide into the pores which are not filled by the sulfur during the process. In the case of high-sulfur loading composites, the manufacturing process as well as the size and morphologies of the carbon are crucial factors that affect the capacity and cycle stability of the Li–S battery.

High strength silica-based ceramics material for investment casting applications: Effects of adding nanosized alumina coatings

A nanosized alumina coating was synthesized on the surface of fused silica particles by electrostatic attraction. The effects of the coated fused silica particles on the cristobalite crystallization behavior, microstructure evolution, and flexural strength of silica-based ceramic cores were investigated. X-ray diffraction (XRD) was used to characterize phase transformations in the specimens, and the results indicated that the formed nanosized alumina coatings could retard cristobalite formation by inducing compressive stress on the fused silica particle surface. A mullite phase was also found due to the reaction of the nanosized alumina coating and the surface of the fused silica when the sintering temperature was increased to 1300 °C. Analysis using scanning electron microscopy equipped with energy dispersive spectrometry (SEM/EDS) suggested that alumina nanoparticles in the coated layer dispersed into a liquid phase and formed a barrier layer to impede the movement of the liquid phase, preventing the pore-filling process and increasing the open porosity of the ceramic specimens. Flexural strengths at room temperature were tested, indicating that increases in the sintering temperature of the specimens without coated fused silica powders had little effect on flexural strength. However, the flexural strength of the specimens with coated fused silica powders increased with increases in sintering temperature. The improvement in flexural strength was related to the reinforcement by sintering necks between particles and the improvement in the strength of the coated fused silica powder.

Exceptionally High CO2 Adsorption at 273 K by Microporous Carbons from Phenolic Aerogels: The Role of Heteroatoms in Comparison with Carbons from Polybenzoxazine and Other Organic Aerogels

AbstractPhenolic aerogels containing oxygen and other polymeric aerogels containing both oxygen and nitrogen (polybenzoxazine and a polyamide‐polyimide‐polyurea co‐polymer) are converted to carbon aerogels (800 °C/Ar), and are etched with CO2 (1000 °C). Etching opens closed pores and increases micropore volumes and size. Heteroatoms are retained in the etched samples. All carbon aerogels are evaluated as CO2 absorbers in terms of their capacity and selectivity toward CH4, H2, and N2. CO2 adsorption capacity is linked to microporosity. In most cases, monolayer coverage of micropore walls is enough to explain CO2 uptake quantitatively. The interaction of CO2 with micropore walls is evaluated via isosteric heats of adsorption, and is stronger with carbons containing only oxygen heteroatoms. The adsorption capacity of those carbons (5–6 mmol g−1) is on par with the best carbon and polymeric CO2 adsorbers known in the literature, with one exception however: etched carbon aerogels from low‐density resorcinol‐formaldehyde aerogels show a very high CO2 uptake (14.8 ± 3.9 mmol g−1 at 273 K, 1 bar) attributed to a pore‐filling process that proceeds beyond monolayer coverage, whereas surface phenoxides engage in a thermally neutral carbonate forming reaction (surface‐O– + CO2 → surface‐O–(CO)–O–) that continues until micropores are filled.

Evaluation of the chloride penetration and service life of self-healing concretes activated by crystalline catalyst

Abstract The main cause of concrete structures deterioration is related to the resistance against the penetration of aggressive agents. Aiming at increase the impermeability and reduce the diffusivity of concrete elements, making it less susceptible to the ingress of chloride ions, the use of crystalline catalyst emerges as a good alternative. Its mechanism of autogenous healing enhances the natural pore-filling process of concrete. The aim of this study is to investigate the influence of the use of crystalline catalyst on the chloride ions penetration and service life prediction of concrete. For the concrete mixtures production, it was used blast-furnace slag blended cement, three different water/cement (w/c) ratios (0.45; 0.55; 0.65), with and without crystalline catalyst, totaling six different mixtures. The concrete specimens were cured in a moist chamber and tested at 28 and 91 days. It was performed tests of compressive strength, rapid chloride permeability (ASTM C1202:12), and silver nitrate colorimetric indicator. The results show that, compared to the reference mixture, the use of crystalline catalyst conserved the compressive strength and reduced the chloride ions penetration up to 30%, increasing service life up to 34%.

Adsorption of 2,4,6-trichlorophenol by magnetic mesoporous SiO2 and the adsorption capacity regeneration by UV photolysis

The adsorption of 2,4,6-trichlorophenol (2,4,6-TCP) on synthesized magnetic mesoporous silica (Fe3O4/SiO2/m-SiO2, MMS) composites and the regeneration of its adsorption capacity through direct UV photolysis was performed in this work. MMS exhibited good performance in removing 2,4,6-TCP from aqueous solutions. The adsorption ratio of 2,4,6-TCP was determined to be influenced by aquatic pH, dissolved humic acids, ionic strength, temperature, and the loaded adsorbents. The adsorption isotherm fit the Freundlich and Polanyi–Manes model better than the Langmuir model, which indicated that the adsorption of 2,4,6-TCP was more likely a pore-filling process. The calculated adsorbed capacity for 2,4,6-TCP on MMS was 55 mg/g. Direct UV photolysis could decompose the adsorbed 2,4,6-TCP and later regenerate the adsorption capacity of MMS to a certain degree; however, the outer mesoporous silica layer was not UV-persistent, and large parts of the mesoporous silica layer were also shown to be corrupted from the Fe3O4/SiO2 core. Therefore, after long duration UV irradiation, the adsorption of 2,4,6-TCP on regenerated MMS was much lower than on freshly synthesized MMS. These results suggest that the photostability of magnetic core-shell-like nanocomposites should be investigated because parts of the composites might leach into the bulk phase during practical use and cause potential environmental risks, similar to other well-known nanomaterials.

Real-time 1D hyperspectral imaging of porous silicon-based photonic crystals with one-dimensional chemical composition gradients undergoing pore-filling-induced spectral shifts

A line-scan hyperspectral imager can provide real-time spectral information at many points along a transect of a gradient-modified material. This is demonstrated by monitoring the optical reflectance spectrum of a porous silicon photonic crystal with a hydrophobic/hydrophilic pore-wall surface composition gradient while it is immersed in water to which ethanol is added. The combination of the hyperspectral imager and the pore-wall composition gradient allows a detailed study of the pore filling process. It is observed that even the most hydrophobic pores fill to a small extent when only a small amount of ethanol has been added. This gradient of filling is in contrast to visible observation of the porous silicon samples, which can suggest a step change in pore filling. The pore-filling process can take many minutes when the solution composition allows pores at a given position along the gradient to be about 50% filled. These observations demonstrate the utility of aligning a line-scan hyperspectral imager with a gradient material.

Luminescence Enhancement of Pyrene/Dispersant Nanoarrays Driven by the Nanoscale Spatial Effect on Mixing

This work presents a simple method to generate ordered chromophore/dispersant nanoarrays through a pore-filling process for a nanoporous polymer template to enhance chromophore luminescence. Fluorescence results combining with the morphological evolution examined by scanning probe microscopy reveal that the enhanced luminescence intensity reaches the maximum intensity as the nanopores of the template are completely filled by the chromophore/dispersant mixture. The variation is attributed to nanoscale spatial effect on the enhanced mixing efficiency of chromophore and dispersant, that is, the alleviation of self-quenching problem, as evidenced by the results of attenuated total reflection Fourier transform IR spectroscopy combining with grazing incident wide-angle X-ray diffraction. The enhanced luminescence of the chromophore/dispersant nanoarrays driven by the nanoscale spatial effect is highly promising for use in designing luminescent nanodevices.

Solid Dispersions of Carvedilol with Porous Silica

Solid dispersion particles of carvedilol (CAR) were prepared with porous silica (Sylysia 350) by the solvent evaporation method in a vacuum evaporator to ensure an effective pore-filling procedure. Two sets were prepared, each with various amounts of CAR in solid dispersions, and with the pore-filling process differing each time. Set A was prepared by a one-step filling method and set B by a multiple-step pore-filling method of CAR into porous silica. The solid dispersions were then characterized using thermal analysis, X-ray diffraction, and nitrogen adsorption experiments. The results showed that the drug release can be significantly improved compared with the dissolution of the drug in its pure crystalline or amorphous state. Drug release from solid dispersion was faster when the drug content in the solid dispersion was low, which enabled the drug to be finely dispersed along the hydrophilic carrier's surface. The results also showed that a multiple-step pore-filling procedure is more effective for drug loading as indicated by the absence of a crystalline drug state, greatly reduced porosity, and improved wettability and physical stability of the amorphous CAR.

Hundred-Nanometer-Size Crystalline Carbon Tubes from Poly(acrylonitrile) Pore-Filling Anodic Aluminum Oxide Templates via Solvent Annealing

With a specific pore-filling process, a solvent-annealing process, graphite-like nanotubes can be fabricated from poly(acrylonitrile) (PAN) pore-filling anodic aluminum oxide templates. The molecular orientation of anisotropic PAN chains was induced by solvent annealing due to capillary filling so as to achieve appropriate molecular packing for carbonization. Consequently, hundred-nanometer-sized carbon nanotubes formed after carbonation, as demonstrated by field-emission scanning electron microscopy and transition electron microscopy observations. Importantly, the carbon nanotubes with a graphite-like structure and high crystallinity can be fabricated, as evidenced by selected area electron diffraction, high resolution transmission electron microscopy, and X-ray diffraction results. Notably, these carbon nanotubes cannot be fabricated using the conventional solution-wetting process. The formation of a core−shell cylinder texture was also demonstrated via multiple filling processes.

Pore-Filling Nanoporous Templates from Degradable Block Copolymers for Nanoscale Drug Delivery

Nanoporous thin-film samples, fabricated from degradable block copolymers, polystyrene-b-poly(l-lactide) (PS-PLLA), were utilized as templates for the formation of ordered nanoarrays. This work elucidates the feasibility of using such nanoporous PS templates as coatings on implantable devices for drug delivery through pore-filling sirolimus. Specific pore-filling process was adopted to increase loading efficiency by exploiting the capillary force associated with the tunable wetting property of the sirolimus solution. After the pore-filling process, sirolimus-loaded cylindrical and lamellar nanoarrays can be obtained. A comparison with those of macroscale templates indicates that the developed nanoporous templates can successfully entrap the loaded drug in nanoscale pores, markedly increasing the duration of drug delivery. As a result, the size, geometry, and depth of the nanoscale pores of the nanoporous templates can be readily controlled to regulate the drug release profiles.