Imprinting Process Research Articles

Effects of mold shape mold vibration and substrate composition in FeNiCrCoMn high entropy alloys nanoimprint

High entropy alloys (HEAs) have received attraction due to their advantage of strength, hardness, fatigue, anticorrosion, and thermal stability. This article examines the impacts of mold shape, composition, and vibration-assisted on the nanoimprinting process of FeNiCrCoMn HEAs by using molecular dynamics simulation. Changing the shape of the mold could improve the imprinting process. The results reveal that increasing the mold angle results in a higher atomic strain rate and a more robust structure transformation of the imprinted shape. In general, a mold with a corner radius performs better than one with a sharp corner in terms of deformation. In detail, as the deformation process becomes smoother as the corner radius increases, the atomic strain, maximum force, and residual stress decrease. The elastic rate tends to increase as the corner radius increases. The FeNiCrCoMn composition has a significant impact on the imprinting process. The 20%Fe substrate has the lowest highest rate of elastic deformation and lowest rates of residual stress, and structural change when compared to other compositions having 30–60% Fe. This composition has a high resistance to deformation than other compositions. Generally, vibration-assisted imprinting may result in a better imprinted shape. Increasing the vibration amplitude results in a larger imprinted shape height, strain, stress, force, and amorphous structure due to the greater plastic deformation. This study sheds more light on the benefits of suitable mold angle, mold fillet radius, alloys composition, and vibration-assisted in the imprinting process.

Humidity Responsive Reflection Grating Made by Ultrafast Nanoimprinting of a Hydrogel Thin Film.

The response time of state-of-the-art humidity sensors is ≈8 s. A faster tracking of humidity change is especially required for health care devices. This research is focused on the direct nanostructuring of a humidity-sensitive polymer thin film and it is combined with an optical read-out method. The goal is to improve the response time by changing the surface-to-volume ratio of the thin film and to test a different measurement method compared to state-of-the-art sensors. Large and homogeneous nanostructured areas are fabricated by nanoimprint lithography on poly(2-hydroxyethyl methacrylate) thin films. Those thin films are made by initiated chemical vapor deposition (iCVD). To the author's knowledge, this is the first time nanoimprint lithography is applied on iCVD polymer thin films. With the imprinting process, a diffraction grating is developed in the visible wavelength regime. The optical and physicochemical behavior of the nanostructures is modeled with multi-physic simulations. After successful modeling and fabrication a first proof of concept shows that humidity dependency by using an optical detection of the first diffraction order peak is observable. The response time of the structured thin film results to be at least three times faster compared to commercialsensors.

Selective Amplification of Plasmonic Sensor Signal for Cortisol Detection Using Gold Nanoparticles.

Herein, gold nanoparticles (AuNP)-modified cortisol-imprinted (AuNP-MIP) plasmonic sensor was developed for signal amplification and real-time cortisol determination in both aqueous and complex solutions. Firstly, the sensor surfaces were modified with 3-(trimethoxylyl)propyl methacrylate and then pre-complex was prepared using the functional monomer N-methacryloyl-L-histidine methyl ester. The monomer solution was made ready for polymerization by adding 2-hydroxyethyl methacrylate to ethylene glycol dimethacrylate. In order to confirm the signal enhancing effect of AuNP, only cortisol-imprinted (MIP) plasmonic sensor was prepared without AuNP. To determine the selectivity efficiency of the imprinting process, the non-imprinted (AuNP-NIP) plasmonic sensor was also prepared without cortisol. The characterization studies of the sensors were performed with atomic force microscopy and contact angle measurements. The kinetic analysis of the AuNP-MIP plasmonic sensor exhibited a high correlation coefficient (R2 = 0.97) for a wide range (0.01–100 ppb) with a low detection limit (0.0087 ppb) for cortisol detection. Moreover, the high imprinting efficiency (k′ = 9.67) of the AuNP-MIP plasmonic sensor was determined by comparison with the AuNP-NIP plasmonic sensor. All kinetic results were validated and confirmed by HPLC.

Fabrication of self-healing magnetic nanoreceptors for glycoprotein via integrating boronate-affinity-oriented and sequential surface imprinting

Molecularly imprinted polymers (MIPs) as artificial receptors have been widely applied in various fields. However, construction of MIPs for precise recognition of glycoprotein still remains a rather challenging task. To overcome this problem, we first fabricated boronate-affinity-oriented and sequential-surface imprinting magnetic nanoparticles (BSIMN) through integrating the boronate-affinity-oriented and sequential surface imprinting. The boronate-affinity-oriented immobilization of glycoprotein template endowed the BSIMN with homogeneous imprinted cavities. In addition, the polydopamine (PDA) imprinted layer was introduced by self-polymerization of dopamine in the first imprinting process, and then the phenylboronic acid (PBA) imprinted layer was introduced by boronate-affinity interaction in the second imprinting process. Surprisingly, the PBA imprinted layer possessed self-healing property due to the presence of pH-dependent boronate-affinity interaction between two imprinted layers. Therefore, the fabricated BSIMN exhibited excellent selectivity toward glycoprotein templates. To quantitatively detect glycoproteins in biological samples, the BSIMN was linked with hydrophilic rhodamine B-loaded/boronic acid-modified graphene oxide (HRBGO), which could selectively label glycoprotein and output amplified signal. In quantitative analysis, target glycoproteins were firstly captured by BSIMN and then specifically labeled by HRBGO; subsequently, the releasing agent was added to release numerous rhodamine B from HRBGO, and the corresponding fluorescence signal was used for further quantitative analysis. The proposed strategy showed ultrahigh sensitivity for ovalbumin, carcinoembryonic antigen and alpha fetoprotein with limit of detection of 4.5 fg mL−1, 3.6 fg mL−1 and 4.2 fg mL−1, respectively, and was successfully applied in determination of these glycoproteins in serum samples.

A Family Imprinting Approach to Nurturing Willing Successors: Evidence From Centennial Family Firms

A critical aspect for the continuity of family businesses (FB) is the existence of willing successors. In this article, we use the imprinting theory to ground an explanation of how the family imprinting process shapes siblings’ willingness to become a successor in the FB. We stylize three family imprinting types based mainly on different family motivations: the FB-centric, the entrepreneurship-centric, and the free-will-centric. The uniqueness of this approach is that it offers an imprinting-based process model capable of explaining the origins of homogeneity and heterogeneity in succession willingness at both the inter- and the intra-family levels.

Plasma assisted micro poling of glassy surfaces: a new tool to achieve liquid crystal multi-domain alignments [Invited

We propose an innovative approach to program the alignment of liquid crystal (LC) assemblies allowing for the formation of multi-domain alignments whose orientation axis and sizes are controlled at the micrometer scale by an electrically patterned glass surface. The glass surface preparation is based on a thermo-electrical imprinting process to induce localized space charge implantations in the glass matrix just below its anode surface. To demonstrate this new approach, a commercial soda-lime glass slide has been polarized using as anode a simple micrometric nickel grid. Characterizing the polarized glass surface by second harmonic generation polarized microscopy; we show an accurate control of both location and spatial components of frozen static fields embedded in the glass as a function of the electrode patterns. The polarized glassy surface is then used in the conception of a LC cell in which homeotropic or planar alignments can be controlled following the electrical pattern induced on the glass surface. This study also points out the importance of plasma discharges spatially controlled along the electrode pattern during the process in order to promote the in-plane electrical polarization effects, which are essential for the programming of the in-plane LC alignment on the polarized glass surface.

55‐2: Roll‐to‐Plate Nanoimprint Lithography as Etching Mask Creating Large‐Area Structured Surfaces

This paper explains how large area Roll‐to‐Plate (R2P) Nanoimprinting is combined with Reactive Ion Etching (RIE) to address the emerging needs of a variety of demanding products. In this process sequence, the scalable R2P imprint process is used to apply a structured mask to the functional surface. In a subsequent etching step the texture is transferred into the layer underneath. Using nanoimprinting and dry‐etching in combination is a powerful method for creating large‐area metal structured surfaces or optical structures in glass while improving mechanical durability and optical clarity at reduced costs and in larger volumes.

Surface imprinted upconversion nanoparticles for selective albumin recognition

Upconversion nanoparticles (UCNPs) have attracted researchers’ attention because these particles transform two or more low-energy infrared (IR) photons into high-energy visible photons via a sequential absorption process. The molecular imprinting method, one of the biomimicking approaches, has remarkable advantages for creating synthetic receptors for molecules of interest. In this study, we have focused our attention on developing novel selective materials simultaneously having upconversion and biorecognition abilities to form a supramolecular complex. We proposed a new approach to synthesize silica-based UCNPs via surface imprinting of albumin that was chosen as a model biomolecule. In the first step, synthesis of surface imprinted upconversion silica nanoparticles and template removal processes were performed. FTIR, SEM, fluorimetry / UV-Vis spectrophotometry, zeta-size / potential measurements and BET (surface area measurements) were performed for the characterization. Biorecognition conditions were optimized and the optimum BSA recognition conditions were determined as BSA initial concentration, interaction time, pH, and temperature as 0.5 mg/mL, 15 min, 4.5, and 25 oC, respectively. The relative selectivity coefficients, designating the selectivity gained by the imprinting process for BSA/hemoglobin, BSA/ovalbumin, and BSA/γ-globulin pairs were calculated as 4.69, 38.37, and 9.66, respectively. In the second step, the synthesis of the magnetic nanoparticles and antibody immobilization onto these particles were investigated. At the final step, sandwich-like supramolecular complex with magnetic nanoparticles (MNPs) and upconversion silica nanoparticles (UC-SiNPs) were done and characterized with UV-Vis spectroscopy, fluorescent spectrometry, and zeta size and potential measurements. In a conclusion, developed molecular imprinted upconversion supramolecular complex will be an alternative and intriguing approach where sandwich-like recognition, detection, and selective adsorption properties are simultaneously required.

Dual functional anode for organic light-emitting devices by directly imprinted nanostructured ultrathin Au film

The ultrathin metal film with excellent electrical conductivity and high visible-band transmittance has attracted considerable attention as a transparent electrode for the organic light-emitting devices (OLEDs). However, the deficient surface morphology and poor continuity of low thickness evaporated metal films and the surface plasmon-polaritons (SPPs) mode induced energy loss still seriously limit the actual efficiency of OLEDs. In this work, the thermal nanoimprint lithography has been further modified and directly applied to fabricate nanostructures onto the ultrathin Au film. During the imprinting process, the surface smoothness and conductivity of the Au film are obviously optimized with the formation of nanostructures. After integrating proper nanostructures into OLEDs, the photons that trapped by SPPs mode within the device were effectively out-coupled. The current efficiency and luminance have been enhanced 45.3% and 18.1%, respectively. Furthermore, the emitting properties of the OLEDs were also modified by the nanostructures, and the directional transmission capability of output light was significantly improved.

Comparison of UV-curable materials for high-resolution polymer nanoimprint stamps

We present a systematic comparison of four resins for nanoimprint intermediate polymer stamps, the standard IPS material, OrmoStamp and two new polymers GMN-PS90 (foil) and GMN-PS40 (liquid). The new polymers are based on acrylated silane and offer sufficiently high Young's modulus and low shrinkage to provide good mechanical stability during the imprint process of well-separated structures. No anti-sticking treatment requires for those new polymers and they can be used at room temperature, which results in better stability of the nanoimprint process. The nanoimprint experiments using four resins showed a superior performance of the GMN-PS90 material in both single-layer and double-layer imprint process with resolution after lift-off about 30 nm. • Comparison of four resins for intermediate nanoimprint stamps • The GMN-PS90 polymer showed the best performance for the Au lift-off applications • Pattern transfer as small as 30 nm demonstrated for the GMN-PS90 resin

Preparation of molecularly imprinted bilayer cryogel columns for selective protein depletion

In this study, bilayer-imprinted cryogels were synthesized for depletion of human serum albumin (HSA) from human serum. For this purpose, a monolayer HSA-imprinted cryogel with 8% monomer concentration was synthesized and second imprinting process was performed using a polymeric solution with 16% monomer concentration in presence of HSA, in the supermacroporous structure of first layer. Thereby, bilayer HSA-imprinted cryogel column (HSA-BLIP) with enhanced surface area was obtained. Bilayer non-imprinted polymer (BL-NIP) and monolayer HSA-imprinted polymers with monomer concentrations of 8% and 16% (HSA-MIP8% and HSA-MIP16%, respectively) were synthesized as the control group. Synthesized columns were characterized by swelling tests, scanning electron microscopy (SEM), multipoint Brunauer-Emmett-Teller (BET) surface area measurement and micro computed tomography (Micro-CT) analysis. Surface areas of HSA-BLIP, BL-NIP, HSA-MIP8% and HSA-MIP16% were found to be 39 m2/g, 37 m2/g, 21 m2/g and 12 m2/g, respectively. Maximum HSA adsorption was calculated as 106.8 mg/g for HSA-BLIP and 5.14 mg/g for BL-NIP. Selectivity studies were conducted in presence of competitor molecules, human hemoglobin (Hb) and immunoglobulin G (IgG). Finally, selective depletion of HSA directly from human serum was studied. In addition, it was demonstrated that HSA-BLIPs can be used up to 10 times without significant decrease in selective adsorption capacity.

A novel fluorescent sensor based on a magnetic covalent organic framework-supported, carbon dot-embedded molecularly imprinted composite for the specific optosensing of bisphenol A in foods

An efficient one-pot strategy for the synthesis of a bisphenol A (BPA) fluorescent sensor based on a magnetic covalent organic framework-supported, carbon dot-embedded molecularly imprinted composite (named MCOF@CD@MIP) is reported for the first time in this work. Herein, MCOFs were prepared via the simple in-situ growth of COF crystals on Fe3O4 nanoparticles and acted as supports to provide a large surface area for CD-embedded MIP layer deposition through a room temperature sol-gel molecular imprinting process. The fabricated MCOF@CD@MIP integrated the useful magnetic properties of Fe3O4, the signal transduction function of CDs, the signal amplification effect derived from the COFs and MIP, and the specific recognition behavior of MIP toward template molecule BPA. Based on the fluorescence quenching behavior of BPA for the MCOF@CD@MIP, a highly sensitive and selective fluorescent MCOF@CD@MIP sensor was developed over the concentration range of 25–3000 μg L-1 with a low detection limit (12 μg L-1). Furthermore, the MCOF@CD@MIP sensor was employed to detect BPA in canned goods and boxed drinks with satisfactory results, which agreed well with those obtained by the traditional high performance liquid chromatography (HPLC) method, demonstrating the good reliability, accuracy and practicality of our constructed sensor.

Imprintability of Newly Hatched Domestic Chicks on an Artificial Object: A Novel High Time-Resolution Apparatus Based on a Running Disc.

In filial imprinting, newly hatched chicks repeatedly approach a conspicuous object nearby and memorize it, even though it is an artificial object instead of their mother hen. Imprinting on an artificial object in a laboratory setting has a clear sensitive period from post hatch days 1–3 in the case of domestic chicks. However, the establishment of imprintability are difficult to investigate because of the limitations of the behavioral apparatus. In this study, we developed a novel behavioral apparatus, based on a running disc, to investigate the learning processes of imprinting in newly hatched domestic chicks. In the apparatus, the chick repeatedly approaches the imprinting object on the disc. The apparatus sends a transistor-transistor-logic signal every 1/10 turn of the disc to a personal computer through a data acquisition system following the chick’s approach to the imprinting object on the monitor. The imprinting training and tests were designed to define the three learning processes in imprinting. The first process is the one in which chicks spontaneously approach the moving object. The second is an acquired process in which chicks approach an object even when it is static. In the third process, chicks discriminate between the differently colored imprinting object and the control object in the preference test. Using the apparatus, the difference in the chicks’ behavior during or after the sensitive period was examined. During the sensitive period, the chicks at post hatch hour 12 and 18 developed the first imprinting training process. The chicks at post hatch hour 24 maintained learning until the second process. The chicks at post hatch hour 30 reached the discrimination process in the test. After the sensitive period, the chicks reared in darkness until post hatch day 4 exhibited poor first learning process in the training. Thus, this apparatus will be useful for the detection of behavioral changes during neuronal development and learning processes.

On-line monitoring of the dopamine-based molecular imprinting processes for protein templates with the assistance of a fluorescent indicator.

On-line monitoring of the dopamine (DA)-based molecular imprinting processes over Fe3O4@SiO2-NH2 nanoparticles (SiMNPs) is reportedby using a real-time quantitative PCR machine. Taking advantages of the efficient fluorescence quenching capability of polydopamine (PDA) and its high binding affinity to rhodamine B (RhB), we performed molecular imprinting against different proteins with free dopamine as the functional monomer and RhB as a fluorescent indicator. Along with the template molecules, the fluorescent indicators were continuously encapsulated into the PDA layer formed on the surface of the SiMNPs, resulting in immediate quenching of the fluorescence, which can be conveniently monitored in real time. As proteins showed sequence-dependent influences on the oxidation of dopamine and subsequent self-assembly on the surface of the SiMNPs, the observed fluorescence signals clearly indicated the polymerization progress in the presence of the template proteins, allowing precise control of the reaction time for different templates at a given initial concentration. The optimum end point of the reaction was found to be when 90 ± 3% of the templates had been encapsulated into the polymer, which offered the highest imprinting factor and selectivity. We applied the approach to prepare a primary PDA-based surface imprinted polymer for a multifunctional protein apurinic/apyrimidinic endonuclease/redox effector factor 1 (APE1). After further introduction of 3-hydroxyphenylboronic acid to the interfaces between APE1 and PDA, the resultant molecularly imprinted polymers (MIP-II) enabled quantitative isolation APE1 from cell lysate samples. The developed approach will be useful for the quantitative preparation of PDA-based MIPs for precious template proteins with limited input quantity. It is also applicable for further study on the effects of different proteins or peptides on the PDA formation reactions.

IMPACT and OSBPL1A are two isoform-specific imprinted genes in bovines

The epigenetic process of genomic imprinting results in the monoallelic expression of genes based on their parental origin. Comparative analysis of imprinted genes between species is useful for investigating the biological significance and regulatory mechanisms of genomic imprinting. Mouse Impact is an imprinted gene, but its human ortholog IMPACT escapes genomic imprinting. Hrh4 and Osbpl1a are the two nearest neighbors of the Impact located in distal and proximal regions, respectively. This study aims to assess the allelic expression of bovine IMPACT, OSBPL1A and HRH4 genes and examine the differentially methylated regions (DMRs) associated with these three genes. Based on an expressed single-nucleotide polymorphism (SNP) approach, we found that both the IMPACT and OSBPL1A genes exhibit isoform-specific monoallelic expression in bovine adult tissues. In the seven detected bovine IMPACT transcripts, only one transcript variant (X6) is monoallelically expressed in bovine adult tissues and paternally expressed in the placenta. However, no DMR was found in the promoter region of the IMPACT gene. We obtained five transcript variants (V1–V5) of the bovine OSBPL1A gene of different lengths that start transcription from distinct alternative promoters by RT–PCR. Only the longest variant V1 was found to be expressed monoallelically in bovine adult tissues and a DMR was identified in its promoter region using the bisulfite sequencing method. Thus, the DMR in OSBPL1A V1 promoter region may contribute to its isoform-specific monoallelic expression. The bovine HRH4 gene is expressed biallelically. Hypermethylation was observed in brains without HRH4 expression, while hypomethylation was found in the spleens with HRH4 expression, so and the level of DNA methylation in the promoter seemed to be related to its expression in tissues.

EGDMA- and TRIM-Based Microparticles Imprinted with 5-Fluorouracil for Prolonged Drug Delivery.

Imprinted materials possess designed cavities capable of forming selective interactions with molecules used in the imprinting process. In this work, we report the synthesis of 5-fluorouracil (5-FU)-imprinted microparticles and their application in prolonged drug delivery. The materials were synthesized using either ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TRIM) cross-linkers. For both types of polymers, methacrylic acid was used as a functional monomer, whereas 2-hydroxyethyl methacrylate was applied to increase the final materials’ hydrophilicity. Adsorption isotherms and adsorption kinetics were investigated to characterize the interactions that occur between the materials and 5-FU. The microparticles synthesized using the TRIM cross-linker showed higher adsorption properties towards 5-FU than those with EGDMA. The release kinetics was highly dependent upon the cross-linker and pH of the release medium. The highest cumulative release was obtained for TRIM-based microparticles at pH 7.4. The IC50 values proved that 5-FU-loaded TRIM-based microparticles possess cytotoxic activity against HeLa cell lines similar to pure 5-FU, whereas their toxicity towards normal HDF cell lines was ca. three times lower than for 5-FU.

Sequential assembly enabled surface precise imprinting on Janus nanosheets for highly specific separation of adenosine 5′-monophosphate

• The sequential imprinting assembly strategy was demonstrated to precisely control the imprinting process. • Janus amphiphilic polymer nanosheets acted as the carrier of J-MIPs to simplify the collection process. • Binding sites with high affinity to AMP of J-MIPs accounted for about 76.71% of the total sites. • J-MIPs could be used for selective enrichment of targeted AMP in complex biological samples. Precise control of imprinting processes and reasonable selection of molecularly imprinted polymers (MIPs) carriers are essential for realizing highly selective and fast separation. In this work, Janus polymer nanosheets (J-PNs) with different wettabilities on two sides were synthesized by self-polymerizing dopamine based on octadecylamine (ODA) lamellae with a bilayer structure, followed by a sequential imprinting assembly of low pKa boronic acid and pyrimidine base monomers on the hydrophilic side of J-PNs to prepare Janus imprinting sorbents (J-MIPs) for highly specific separation of adenosine 5′-monophosphate (AMP). The sequential assembly strategy integrated two different functional monomers together to simultaneously interact with the surrounding template AMP molecule and to precisely control the imprinting site orientation, enabling the resulting J-MIPs with strong and specific binding toward AMP. Janus amphiphilic J-MIPs can be well fixed at the dodecane/water interface, which was benefit for their fast recycle and simple regeneration, and the uptake amount of the fifth adsorption/elution cycle was 86.08% of the first one. The equilibrium time and maximum adsorption capacity of tailor-made J-MIP were 4.0 h and 13.69 μmol g −1 at 298 K, respectively. Taking the advantage of cooperative multi-point interaction, binding sites with high affinity to AMP accounted for about 76.71% of the total sites, and the high imprinting factor (2.182) of the J-MIP against non-imprinted counterpart was observed. In addition, 61.30% of AMP in spiked human serum sample can be selectively extracted by J-MIPs, due to the highly specific receptor sites from sequential imprinting assembly.

Solution-Driven Imprinting Lithography of Sol-Gel ZnO Thin Films for Liquid Crystal Display.

We present a simple and economically convenient method to fabricate nanopatterned ZnO films by imprinting lithography and use them for the layer alignment of liquid crystal (LC) displays. First, a one-dimensional nanopattern was obtained by laser interference lithography on a silicon wafer, and the silicon mold replica was transferred onto a flexible polydimethylsiloxane (PDMS) sheet for conformal patterning. The so-obtained PDMS mold was then applied on a ZnO film spin-coated on a glass substrate. During the imprinting process, the temperature was controlled from 100 to 250 °C to observe the transferring morphologies of the ZnO film; the nanopattern was successfully transferred at annealing temperatures of 200 and 250 °C because the ZnO film at the sol state filled the cavities of the PDMS nanopattern and solidified, forming a negative replica of the nanopattern. The direction of the nanopatterned ZnO film served as a guide for aligning the LC molecules on the LC surface at the centimeter scale and, due to their elastic characteristics and group behavior, propagating their directional states in the LC bulk. The resulting LC cell exhibited an enhanced electro-optical performance and high thermal endurance above 180 °C. The geometry of the alignment layer increased the electric field on the ZnO film and showed reduced threshold voltage. In addition, since flexible devices are generally based on polyimide, which imidized at around 200 °C, the relatively low annealing temperatures of our fabricated nanopatterned ZnO film allow it to be mounted on such devices without any deterioration of the underlying thermoplastic substrate. Therefore, nanopatterned ZnO has a considerable potential for advanced LC displays.

A deep insight for TBBPA imprinting on PVP-assisted separation membrane: Elucidation of detailed chemical transition in membrane preparation and imprinting process

Given that the widespread existence of Tetrabromobisphenol A (TBBPA) in water can cause severe hazard to human health and the eco-environment, it is imperative to develop an eco-friendly functional material with precise capture and separation capacity towards TBBPA. Herein, we found a feasible route to achieve above purpose by preparing TBBPA-molecularly imprinted membranes (TB-MIMs). Polyvinylpyrrolidone (PVP) with different amounts were firstly blended into the membrane substrate to adjust the pore size and endow the membrane surface with convertible functional groups and hydrophilicity, followed by the modification via gallic acid and VTMOS. Subsequently, the click chemistry was finally employed to engineer the imprinting sites of TBBPA. The membrane incorporated with 7 wt% of PVP exhibited significantly enhanced water flux (196 L m-2h−1), water contact angle (78.6 ± 2.2°) and porosity (75.4%) than that of other membranes with different additive amounts of PVP, which was appropriate for the follow-up imprinting process. TB-MIMs exhibited comparable permeation selectivity containing interferents (3.72 for BPA, 3.86 for BP, 3.92 for BBPA), which was far superior to the TB-NIMs. The chemical transition and structural evolution over preparation and adsorption process were systematically investigated through in situ FTIR spectra and DFT, which proven the feasibility of strategy. It is worth noting that the resulting TB-MIMs showed a remarkable stability in various chemical environments and long-term stability in continuous operation process, which showed great promise in practical application.

Investigation on the roll-to-plate imprinting of metallic surface micro dimples

Large-area functional metallic surface microstructures have been increasingly utilized in various industrial fields. As an efficient and economical method in fabricating large-area functional metallic surface microstructures, the roll-to-plate (R2P) imprinting process with the flat die was proposed to experimentally fabricate functional micro dimple arrays on the surface of the metallic substrate. The effects of the rolling direction, die cavity aspect ratio, die feature density and grain sizes on the forming results were investigated using pure copper specimens with different grain sizes. The transfer ratio of surface structures decreases with the increase of the die feature density and die cavity aspect ratio, respectively. The flowing differences of material in the rolling direction and transverse directions lead to the inconformity of section profile of formed dimples in the two directions. The depth of dimples in the rolling direction is prominently greater than that in the transverse direction. The depth difference of dimples in the two directions increases with the increase of rolling depth and reduces with the increase of die cavity width. The surface morphology of formed specimens obviously depends on the material flowing direction, grain sizes and rolling depth. The surface roughness, surface roughness scatter and flatness of the formed specimens increase with the grain size. The symmetry of cross sectional micro hardness distribution on both sides of the formed dimple in the rolling direction is poorer than that on both sides of the formed dimple in the transverse direction. The asymmetry of cross sectional micro hardness distribution on both sides of the formed dimple in the rolling direction becomes more prominent with the increase of grain sizes.