Porous Polycarbonate Research Articles

A robust antagonistically assembled triboelectric nanogenerator based on dead‐end closed pore through a one‐step improved phase separation

AbstractThe ongoing global energy crisis presents a significant challenge all over the world. In this study, triboelectric nanogenerator (TENG) made of recyclable thermoplastic polycarbonate has been proposed as a promising environmentally friendly solution due to its potential capability to convert low‐frequency mechanical energy sources such as human motion and ocean waves into electricity with potential applications including powering wearable electronic devices and self‐powered sensors. We introduce an antagonistically structured TENG (A‐TENG) composed of honeycomb porous polycarbonate (hc‐PC) and convex‐patterned dimethylsiloxane, employing a novel one‐stage improved phase separation method. This A‐TENG overcomes the demerits of others thanks to its high surface contact area, simplified fabrication process, enhanced energy conversion efficiency, and cost‐effectiveness, requiring minimal investment. More importantly, this work utilized hc‐PC as a framework for slippery liquid‐infused porous surface (SLIPS) based TENG owing to the special honeycomb porous structure to impregnate silicon oil within pore arrays and mechanically support the whole system. The practical application of SLIPS‐TENG was demonstrated while deployed on the house rooftop to harvest raindrop energy and act as a rain detection sensor.

AlveoMPU: Bridging the Gap in Lung Model Interactions Using a Novel Alveolar Bilayer Film.

The alveoli, critical sites for gas exchange in the lungs, comprise alveolar epithelial cells and pulmonary capillary endothelial cells. Traditional experimental models rely on porous polyethylene terephthalate or polycarbonate membranes, which restrict direct cell-to-cell contact. To address this limitation, we developed AlveoMPU, a new foam-based mortar-like polyurethane-formed alveolar model that facilitates direct cell-cell interactions. AlveoMPU features a unique anisotropic mortar-shaped configuration with larger pores at the top and smaller pores at the bottom, allowing the alveolar epithelial cells to gradually extend toward the bottom. The underside of the film is remarkably thin, enabling seeded pulmonary microvascular endothelial cells to interact with alveolar epithelial cells. Using AlveoMPU, it is possible to construct a bilayer structure mimicking the alveoli, potentially serving as a model that accurately simulates the actual alveoli. This innovative model can be utilized as a drug-screening tool for measuring transepithelial electrical resistance, assessing substance permeability, observing cytokine secretion during inflammation, and evaluating drug efficacy and pharmacokinetics.

Micro‐Casting/Assembly Technology Based on Bismuth‐Based Liquid Metal

AbstractComplex and precise 3D microfabrication technology is the basis for the development of fields including chip‐based bioassay, microelectronic communication, and micromachine manufacturing. Among them, assembled 3D structures provide new ideas to the development of 3D integration of 2D components due to their convenience and high efficiency. In this work, a micro‐casting/assembly technique that can create 3D micro devices is provided with bismuth‐based liquid metal (LM). The liquid metal is first injected into a micro‐mold. The micro‐mold is made by polydimethylsiloxane (PDMS) and porous polycarbonate track‐etched (PCTE) membranes. The mold is then treated with ethanol and deionized water to release the inner injected 2D micro metal components. The effect of each parameter on the generated metal structures is experimentally validated and a LM line with a minimum width of 10 µm is also obtained. For making more functional components, the 2D structures are assembled into 3D. To demonstrate the potential of the technique, reconfigurable micro‐antennas and 3D flow sensors are fabricated and tested at the end of this work, demonstrating potential applications for the micro casting/assembly technology.

Effect of copper doping on the photocatalytic performance of Ni2O3@PC membrane composites in norfloxacin degradation.

In this study, copper (Cu) and nickel oxide (Ni2O3) microtubes (MTs) were synthesized using an electroless template deposition technique within porous polycarbonate (PC) track-etched membranes (TeMs) to obtain Cu@PC and Ni2O3@PC composite membranes, respectively. The pristine PC TeMs featured nanochannels with a pore density of 4 × 107 pores per cm2 and an average pore diameter of 400 ± 13 nm. The synthesis of a mixed composite, combining Cu and Ni2O3 within the PC matrix, was achieved through a two-step deposition process using a Ni2O3@PC template. An analysis of the resultant composite structure (Cu/Ni2O3@PC) confirmed the existence of CuNi (97.3%) and CuO (2.7%) crystalline phases. The synthesized catalysts were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) analysis, and atomic force microscopy (AFM). In photodegradation assessments, the Cu/Ni2O3@PC mixed composite demonstrated higher photocatalytic activity, achieving a substantial 59% degradation of norfloxacin (NOR) under UV light irradiation. This performance surpassed that of both Ni2O3@PC and Cu@PC composites. The optimal pH for maximum NOR removal from the aqueous solution was determined to be pH 5, with a reaction time of 180 min. The degradation of NOR in the presence of these composites adhered to the Langmuir-Hinshelwood mechanism and a pseudo-first order kinetic model. The reusability of the catalysts was also investigated for 10 consecutive runs, without any activation or regeneration treatments. The Cu@PC membrane catalyst demonstrated a marked decline in degradation efficiency after the 2nd test cycle, ultimately catalyzing only 10% of NOR after the 10th cycle. In contrast, the Ni2O3@PC based catalyst demonstrated a more stable NOR degradation efficiency throughout all 10 runs, with 27% NOR removal observed during the final test. Remarkably, the catalytic performance of the Cu/Ni2O3@PC mixed composite remained highly active even after being recycled 4 times. The degradation efficiency exhibited a gradual reduction, with a 17% decrease after the 6th run and a cumulative 35% removal of NOR achieved by the 10th cycle. Overall, the findings indicate that Cu/Ni2O3@PC mixed composite membranes may represent an advancement in the quest to mitigate the adverse effects of antibiotic pollution in aquatic environments and hold significant promise for sustainable water treatment practices.

Direct deep UV lithography to micropattern PMMA for stem cell culture.

Microengineering is increasingly being used for controlling the microenvironment of stem cells. Here, a novel method for fabricating structures with subcellular dimensions in commonly available thermoplastic poly(methyl methacrylate) (PMMA) is shown. Microstructures are produced in PMMA substrates using Deep Ultraviolet lithography, and the effect of different developers is described. Microgrooves fabricated in PMMA are used for the neuronal differentiation of mouse embryonic stem cells (mESCs) directly on the polymer. The fabrication of 3D, curvilinear patterned surfaces is also highlighted. A 3D multilayered microfluidic chip is fabricated using this method, which includes a porous polycarbonate (PC) membrane as cell culture substrate. Besides directly manufacturing PMMA-based microfluidic devices, an application of the novel approach is shown where a reusable PMMA master is created for replicating microstructures with polydimethylsiloxane (PDMS). As an application example, microchannels fabricated in PDMS are used to selectively expose mESCs to soluble factors in a localized manner. The described microfabrication process offers a remarkably simple method to fabricate for example multifunctional topographical or microfluidic culture substrates outside cleanrooms, thereby using inexpensive and widely accessible equipment. The versatility of the underlying process could find various applications also in optical systems and surface modification of biomedical implants.

Effects of structure, size and non-magnetic Cu layer thickness on magnetization switching behavior in Ni/Cu/M (M [formula omitted] Ni, Co) cylindrical nanowires

We have investigated the dependence of the magnetization switching behavior on the structure, size and nonmagnetic Cu layer thickness (tCu) in Ni/Cu/M (M = Ni, Co) cylindrical nanowires fabricated by electrodeposition using porous polycarbonate templates. The crystal structure of the Ni nanowires was (111)- or (200)-oriented polycrystalline fcc, while that of Co nanowires was (100)- or (101)-oriented hcp and/or (111)-oriented polycrystalline fcc. When the wire diameter (d) was 50 nm, the squareness ratio (Mr/Ms) for M = Ni, as estimated from the magnetization curve, is almost constant at Mr/Ms∼0.79 (Mr/Ms∼0.64 for M = Co) when tCu increases from 0 to 500 nm. When d=100nm, Mr/Ms decreases by 41% from 0.71 to 0.42 with increasing tCu from 0 to 700 nm for M = Ni, while Mr/Ms decreases by 25% from 0.53 to 0.40 with varying tCu from 0 to 500 nm for M = Co. The threshold Cu layer thickness (tCuth) beyond which Mr/Ms becomes constant at d=100nm is ∼500 nm for M = Ni and ∼300 nm for M = Co. The results are qualitatively consistent with those obtained from our micromagnetic simulation and analysis. The observed difference in the tCuth dependence of Mr/Ms between M = Ni and Co is attributed to the change in the magnetic domain structure of the nanowires as it sensitively varies with the magnetocrystalline anisotropy. On the other hand, the coercive force of the nanowires shows a small tCu dependence for both d=50 and 100 nm. These results indicate that the layered structure in the nanowires governs the magnetic domain structure, though the effect on the magnetization switching behavior is indeed relatively small.

Adsorptive removal of sulphonamides in water by graphene oxide-doped porous polycarbonate derived from optical disc waste

Adsorptive removal of sulphonamides in water by graphene oxide-doped porous polycarbonate derived from optical disc waste

A novel approach for extracting magnetic properties of double-shell nanotubes of Prussian blue and its Cr analog with the use of a mathematical hysteresis decomposition

This work presents the synthesis and investigation of Prussian blue and its chromium analog nanotubes obtained inside porous polycarbonate track etch (PCTE) membranes by electrochemical deposition. The process yielded nanotubes with outer diameters between 50 and 200 nm and thicknesses of approximately 30 nm. It was found that decreasing nanotube diameter had little or no effect on magnetic properties (critical temperature and coercivity). Additionally, the growing process and the basic properties of double-shell nanotubes are described. These double-shell structures show a two-component magnetic behavior. By using the theoretical model, it is possible to decompose the hysteresis loops into the base constituents and derive the relative concentration of each counterpart.

Biofabrication, biochemical profiling, and in vitro applications of salivary gland decellularized matrices via magnetic bioassembly platforms.

Trending three-dimensional tissue engineering platforms developed via biofabrication and bioprinting of exocrine glands are on the rise due to a commitment to organogenesis principles. Nevertheless, a proper extracellular matrix (ECM) microarchitecture to harbor primary cells is yet to be established towards human salivary gland (SG) organogenesis. By using porcine submandibular gland (SMG) biopsies as a proof-of-concept to mimic the human SG, a new decellularized ECM bioassembly platform was developed herein with varying perfusions of sodium dodecyl sulfate (SDS) to limit denaturing events and ensure proper preservation of the native ECM biochemical niche. Porcine SMG biopsies were perfused with 0.01%, 0.1%, and 1% SDS and bio-assembled magnetically in porous polycarbonate track-etched (PCTE) membrane. Double-stranded DNA (dsDNA), cell removal efficiency, and ECM biochemical contents were analyzed. SDS at 0.1% and 1% efficiently removed dsDNA (< 50ng/mg) and preserved key matrix components (sulfated glycosaminoglycans, collagens, elastin) and the microarchitecture of native SMG ECM. Bio-assembled SMG decellularized ECM (dECM) perfused with 0.1-1% SDS enhanced cell viability, proliferation, expansion confluency rates, and tethering of primary SMG cells during 7 culture days. Perfusion with 1% SDS promoted greater cell proliferation rates while 0.1% SDS supported higher acinar epithelial expression when compared to basement membrane extract and other substrates. Thus, this dECM magnetic bioassembly strategy was effective for decellularization while retaining the original ECM biochemical niche and promoting SMG cell proliferation, expansion, differentiation, and tethering. Altogether, these outcomes pave the way towards the recellularization of this novel SMG dECM in future in vitro and in vivo applications.

Nano porous polycarbonate membranes stimulating cell adhesion and promoting osteogenic differentiation and differential mRNA expression

Tissue engineering is thought to be the ideal therapy for bone defect reconstructive treatment. In this study, we present a method of utilizing micro/nano porous polycarbonate membranes (PCMs) as the extracellular matrix to cultivate the human periodontal ligament cells (hPDLCs) and investigate the osteogenic differentiation of those cells. We also compared the osteogenic enhancing abilities of different pore size PCMs. The pore diameters of the candidate membranes are 200 nm, 800 nm, 1200 nm, and 10 μm respectively, and their physical properties are identified. After seeding and cultivating on the PCMs, hPDLCs can be stimulated to undergo osteogenic differentiation, in which the 200 nm PCM is proved to have the most optimal osteo-induction ability. The results of in vivo experiments provide strong evidence suggesting that the hPDLCs stimulated by 200 nm PCM greatly accelerates the healing of bone reconstruction in mice skull defects, as well as promote the process of ectopic osteogenesis. RNA-sequencing was conducted to determine the differential mRNA expression profile during the osteogenesis process of hPDLCs on PCMs. GO and KEGG enrichment analysis were conducted to study the regulatory mechanisms, in which osteogenic marker expression such as Hippo, TGF-β, and PI3K-Akt signaling pathways were significantly up-regulated. The up-regulation indicates the promising potential of nano porous PCMs for promoting osteogenesis for bone regeneration applications. Ultimately, signaling pathways that promote osteogenesis warrants further exploration.

Superhydrophobic polycarbonate blend monolith with micro/nano porous structure for selective oil/water separation

Herein, a porous polycarbonate blend monolith with hierarchical micro-nano structure using fluorine-free and low-cost material via a simple thermally induced phase separation is successfully prepared. The unique micro-nano structure endows the monolith with high porosity (90%) and low density (93 mg/cm 3 ), as well as strong superhydrophobicity (water contact angle of 159°) and superoleophilicity. It shows high saturation adsorption capacity (6.25–10.58 g/g) and rapid adsorption rate (20 s reach adsorption equilibrium). Furthermore, outstanding environmental resistance in a variety of harsh conditions, such as contact angle varies slightly under various pHs (1–14) and the constant adsorption capacity at different temperatures (0–100 °C), is found. Additionally, the monolith displays good recycling performance for at least 10 cycles by simply pumping and evaporating, indicating a good application prospect in the field of practical oil-water separation. • Superhydrophobic PDMS/PC monolith with hierarchical micro-nano structure is prepared. • Monolith endows the high porosity (90.8%) and low density (93 mg/cm 3 ). • It has outstanding environmental resistance and constant adsorption capacity at 0–100 °C.

A well-designed polystyrene/polycarbonate membrane for highly saline water desalination using DCMD process

A novel porous polycarbonate (PC) membrane was fabricated using ethanol as non-solvent deploying immersion-precipitation process. To further increase surface hydrophobicity, polystyrene (PS) microbeads were sprayed on PC support using an air-assisted electrospraying process. Due to the micro/nano roughness of the PS layer, the formed dual-layer PS/PC membrane possessed outstanding wetting resistance over the neat PC membrane. The water contact angle (WCA) of the neat PC and PS/PC membranes was measured as 95.2 and 155.1°, respectively. Liquid entry pressure of water represented a considerable enhancement of 84.6% compared to the neat membrane. Direct contact membrane distillation (DCMD) evaluation was performed using the fabricated and commercially available polytetrafluoroethylene (PTFE) membranes. Using concentrated saline water as feed (150 g/L), only PS reinforced PC (PS/PC) membrane showed nonwetting capability with stable DCMD performance during continuous long-term DCMD evaluation. Superhydrophobicity of PS/PC not only diminished pore wetting but also increased permeate flux considerably (45.9%↑) to produce high-quality permeate flux (˂4.6 μS/cm). Considering these attributes, using the low-cost PC polymer along with the high-productive air-assisted electrospraying process is a facile route to fabricate decent membranes for the membrane distillation (MD) process.

Press Bonding of Heated Porous Aluminum and Polycarbonate

Press Bonding of Heated Porous Aluminum and Polycarbonate

Friction welding of porous aluminum and polycarbonate plate

Composite materials consisting of porous aluminum and resin are expected to meet the current demand for the weight reduction of parts. The objective of this study is to introduce friction welding for joining porous aluminum and a polycarbonate plate. The advantages of friction welding are that it is a simple process and the joining surface is locally and directly heated by the friction heat generated between the porous aluminum and the polycarbonate plate. We showed that joining of porous aluminum and a polycarbonate plate can be achieved by friction welding via the anchor effect without the collapse of pores. The observed joining strength was similar to the strength of the porous aluminum itself.

Characterization of neuronal viability and network activity under microfluidic flow

BackgroundMicrofluidics technology has the potential to allow precise control of the temporal and spatial aspects of solute concentration, making it highly relevant for the study of volume transmission mechanisms in neural tissue. However, full utilization of this technology depends on understanding how microfluidic flow at the rates needed for rapid solution exchange affects neuronal viability and network activity. New methodWe designed a tape-based pressurized microfluidic flow system that is simple to fabricate and can be attached to commercial microelectrode arrays. The device is multi-layered, allowing the inclusion of a porous polycarbonate membrane to isolate neuronal cultures from shear forces while maintaining diffusive exchange of solutes. We used this system to investigate how flow affected survival and spiking patterns of cultured hippocampal neurons. ResultsViability and network activity of the cultures were reduced in proportion to flow rate. However, shear reduction measures did not improve survival or spiking activity; media conditioning in conjunction with culture age proved to be the critical factors for network stability. Diffusion simulations indicate that dilution of a small molecule accounts for the deleterious effects of flow on neuronal cultures. Comparison with existing methodsThis work establishes the experimental conditions for real time measurement of network activity during rapid solution exchange, using multi-layered chambers with reversible bonding that allow for reuse of microelectrode arrays. ConclusionsWith correct media conditioning, the microfluidic flow system allows drug delivery on a subsecond timescale without disruption of network activity or viability, enabling in vitro reproduction of volume transmission mechanisms.

Electrodeposited Ni-Rich Ni-Pt Mesoporous Nanowires for Selective and Efficient Formic Acid-Assisted Hydrogenation of Levulinic Acid to γ-Valerolactone.

In pursuit of friendlier conditions for the preparation of high-value biochemicals, we developed catalytic synthesis of γ-valerolactone by levulinic acid hydrogenation with formic acid as the hydrogen source. Both levulinic and formic acid are intermediate products in the biomass transformation processes. The objective of the work is twofold: the development of a novel approach for milder synthesis conditions to produce γ-valerolactone and the reduction of the economic cost of the catalyst. Ni-rich Ni–Pt mesoporous nanowires were synthesized in an aqueous medium using a combined hard–soft-template-assisted electrodeposition method, in which porous polycarbonate membranes controlled the shape and the Pluronic P-123 copolymer served as the porogen agent. The electrodeposition conditions selected favored nickel deposition and generated nanowires with nickel percentages above 75 atom %. The increase in deposition potential favored nickel deposition. However, it was detrimental for the porous diameter because the mesoporous structure is promoted by the presence of the platinum-rich micelles near the substrate, which is not favored at more negative potentials. The prepared catalysts promoted the complete transformation to γ-valerolactone in a yield of around 99% and proceeded with the absence of byproducts. The coupling temperature and reaction time were optimized considering the energy cost. The threshold operational temperature was established at 140 °C, at which, 120 min was sufficient for attaining the complete transformation. Working temperatures below 140 °C rendered the reaction completion difficult. The Ni78Pt22 nanowires exhibited excellent reusability, with minimal nickel leaching into the reaction mixture, whereas those with higher nickel contents showed corrosion.

A comprehensive review of template-synthesized multi-component nanowires: From interfacial design to sensing and actuation applications

Nanowires are one of the most promising nano-building blocks for many applications, including sensors/biosensors, electronics, photonics, energy conversion and storage devices, MEMS and NEMS, biotechnology and nanomedicine. With the growing demands of multi-purpose and multi-functional materials in these fields, different types of multi-component nanowires with complex structures have been designed and fabricated. Among various fabrication methods, porous anodic aluminum oxide (AAO) and polycarbonate (PC) membranes are well-established hard templates that have been used for synthesizing a variety of nanowires and nanowire structures. In this article, a comprehensive review of template-synthesized multi-component nanowire structures has been given, including multi-segmented, core-shell and multi-element nanowires, which can be synthesized by using these hard templates in a sequential or parallel way. Besides, the assembly and integration of different functions and properties into smaller and lighter devices require careful interfacial design and synthesis of multi-component nanowires. The interfacial structure and properties, such as interface uniformity, intermetallic compound formation and surface oxidation, have significant impact on the electrical and thermal conductivity, mechanical strength, functionality, stability and reliability of nanowire-based electronics and devices. A rational interfacial design is crucially important to improve these properties of nanowire devices for emerging multi-functional sensors and actuators, due in fact that sensors and actuators are among the most important components in many electronics and products. Multi-component nanowire based sensors and actuators have potential applications in a wide range of mechanical, electrical, thermal, and biomedical devices.

Pillar[5]arene-functionalized nanochannel platform for detecting chiral drugs

Chirality is a fascinating and essential feature of life and highly associated with many significant pharmaceutical, chemical, and biological processes. The construction of chiral recognition platform is a hot research topic and challenging assignment. Herein, we report an electrochemical method by differential pulse voltammetry (DPV) for the enantioselective recognition of chiral drug propranolol (R/S-PPL) through a nanochannel platform based on the N-acetyl-l-cysteine functionalized pillar[5]arenes derivative NALC-P5 and the porous polycarbonate membrane. The chiral discrimination depends on the difference in the supramolecular host-guest interaction between the chiral NALC-P5 and the R/S-PPL. The transmission rate of the R/S-PPL can be regulated in the nanochannel and we can achieve the selective transport of the chiral drugs. This simple electrochemical technique has potential applications as a general platform for the recognition of chiral molecules.

Development of an Organ-on-a-Chip-Device for Study of Placental Pathologies.

The human placenta plays a key role in reproduction and serves as a major interface for maternofetal exchange of nutrients. Study of human placenta pathology presents a great experimental challenge because it is not easily accessible. In this paper, a 3D placenta-on-a-chip model is developed by bioengineering techniques to simulate the placental interface between maternal and fetal blood in vitro. In this model, trophoblasts cells and human umbilical vein endothelial cells are cultured on the opposite sides of a porous polycarbonate membrane, which is sandwiched between two microfluidic channels. Glucose diffusion across this barrier is analyzed under shear flow conditions. Meanwhile, a numerical model of the 3D placenta-on-a-chip model is developed. Numerical results of concentration distributions and the convection–diffusion mass transport is compared to the results obtained from the experiments for validation. Finally, effects of flow rate and membrane porosity on glucose diffusion across the placental barrier are studied using the validated numerical model. The placental model developed here provides a potentially helpful tool to study a variety of other processes at the maternal–fetal interface, for example, effects of drugs or infections like malaria on transport of various substances across the placental barrier.

Rapid Fabrication of Membrane-Integrated Thermoplastic Elastomer Microfluidic Devices.

Leveraging the advantageous material properties of recently developed soft thermoplastic elastomer materials, this work presents the facile and rapid fabrication of composite membrane-integrated microfluidic devices consisting of FlexdymTM polymer and commercially available porous polycarbonate membranes. The three-layer devices can be fabricated in under 2.5 h, consisting of a 2-min hot embossing cycle, conformal contact between device layers and a low-temperature baking step. The strength of the FlexdymTM-polycarbonate seal was characterized using a specialized microfluidic delamination device and an automated pressure controller configuration, offering a standardized and high-throughput method of microfluidic burst testing. Given a minimum bonding distance of 200 μm, the materials showed bonding that reliably withstood pressures of 500 mbar and above, which is sufficient for most microfluidic cell culture applications. Bonding was also stable when subjected to long term pressurization (10 h) and repeated use (10,000 pressure cycles). Cell culture trials confirmed good cell adhesion and sustained culture of human dermal fibroblasts on a polycarbonate membrane inside the device channels over the course of one week. In comparison to existing porous membrane-based microfluidic platforms of this configuration, most often made of polydimethylsiloxane (PDMS), these devices offer a streamlined fabrication methodology with materials having favourable properties for cell culture applications and the potential for implementation in barrier model organ-on-chips.