Microporous Films Research Articles

Design and Development of Enhanced Antimicrobial Breathable Biodegradable Polymeric Films for Food Packaging Applications.

The principle of breathable food packaging is to provide the optimal number of pores to transfer a sufficient amount of fresh air into the packaging headspace. In this work, antimicrobial microporous eco-friendly polymeric membranes were developed for food packaging. Polylactic acid (PLA) and polycaprolactone (PCL) were chosen as the main packaging polymers for their biodegradability. To develop the microporous films, sodium chloride (NaCl) and polyethylene oxide (PEO) were used as porogenic agents and the membranes were prepared using solvent-casting techniques. The results showed that films with of 50% NaCl and 10% PEO by mass achieved the highest air permeability and oxygen transmission rate (O2TR) with PLA. Meanwhile, blends of 20% PLA and 80% PCL by mass showed the highest air permeability and O2TR at 100% NaCl composition. The microporous membranes were also coated with cinnamaldehyde, a natural antimicrobial ingredient, to avoid the transportation of pathogens through the membranes into the packaged foods. In vitro analysis showed that the biodegradable membranes were not only environmentally friendly but also allowed for maximum food protection through the transportation of sterile fresh air, making them ideal for food packaging applications.

Enhancement of Electrochromic Switching Properties with Tröger's Base-Derived Intrinsic Microporous Polyamide Films.

The formation of Tröger's Base (TB) configuration is a useful approach to synthesize polymers of intrinsic microporosity (PIM). Herein, the V-shaped TB scaffold is incorporated to prepare electrochromic (EC) polyamide with electroactive triphenylamine (TPA) moiety. The presence of intrinsic microporosity derived from inefficient packing of TB scaffolds can facilitate the counterions diffusion between electroactive species and electrolytes. Consequently, the resulting TB-based polyamide exhibits enhanced EC behaviors, such as a lower driving potential, reduced the difference of redox potentials ΔE, and shorter switching response time compared to the corresponding EC counterpart polyamide.

Breath figure templated self-assembly of surface-acylated cellulose nanowhiskers confined as honeycomb films

The self-assembly of cellulose nanowhiskers (CNWs) in confined geometries provides a powerful method for the fabrication of novel structures. Herein, ordered honeycomb microporous films were first prepared with surface-acylated CNWs (CNWs-SU) through the breath figure method. Resulting films showed highly porous order over large regions and the iridescent color was only displayed by their rims, which is different from traditional dish-cast CNW films showing the iridescent color over the whole area. This is mainly due to the condensation of water droplets forming three-dimensional (3D) geometry, which forced CNWs-SU to self-assemble into cholesteric architectures in confined geometry and resulted in the iridescent color of the rims after drying. The mechanism was further studied by investigating the critical influencing factors, primarily the concentration of CNW-SU suspensions, the relative humidity of the atmosphere and the surface-attached moieties. In particular, CNW-SU suspensions with a concentration of 3 mg/mL at the relative humidity of 75% preferentially formed honeycomb films with uniform pores. Too low or too high concentrations of CNW-SU suspensions or relative humidity are not preferable for uniform porous films. CNWs-SU with further immobilized octadecane or fluoroalkyl groups on their surface strongly affected the formation of uniform porous films because of higher hydrophobicity and accompanying inhomogeneous condensation of water droplets. This work provides a novel method to study the interactions of CNWs beyond the planar geometry and the formation of uniform porous films solely with CNWs with structural colors open up interesting possibilities for broad application in photonic nanomaterials.Graphic abstract

Novel monomers with N‐methyl‐D‐glucamine segments and their application in structured porous materials for arsenic capture

AbstractThe N‐methyl‐D‐glucamine moieties exhibit high ability and selectivity toward arsenate ions in water by a complexation mechanism that involves their hydroxyl groups. In this work, the syntheses of two monomers containing N‐methyl‐D‐glucamine, namely 4‐vinylbenzyl‐N‐methyl‐D‐glucamine (VbNMDG), and N‐methyl‐D‐glucamine methacrylamide (MNMDG) were studied. Different synthetic routes were considered in order to obtain liquid monomers able to polymerize and selectively capture arsenic. Furthermore, the incorporation of protective groups like trimethylsilyl moieties in the molecular structure was assessed to prevent transfer reactions during further polymerization. After polymerization, hydroxyl groups were deprotected using hydrofluoric acid. Following this methodology, structured microporous polymeric films based on colloidal crystal templates were prepared. NMR and FTIR techniques were used to follow the reactions and to determine the chemical structure of the obtained products. The morphology of materials was characterized by SEM. The performances of the developed polymeric films to selectively capture arsenic were determined. Films showed an improved and reproducible sensitivity to arsenic detection exhibiting high values of arsenic capturing capability (around 90%).

Wound dressings based on chitosan/gelatin/MgO composite films

The microporous films comprised of chitosan (CS), gelatin (Gel) and magnesium oxide nanoparticles (MgO NPs) were developed as a wound-healing material using the lyophilization technique. The chemical structure, composition and morphology of the films were evaluated by FTIR, XRD, EDX and SEM. Also, the swelling, mechanical, biodegradation, cell viability, antimicrobial property, bioactivity and cell migration capability of the porous films were determined to evaluate their suitability as a wound-dressing material. The average diameter of pores and porosity of the films were in the range of 73 − 103 μm and 57 − 78%, respectively, based on the content of MgO NPs. Compared to control CS/Gel film, the CS/Gel/MgO films presented improved swelling behavior, mechanical strength, antimicrobial activity against the strains of bacteria and fungi and controlled in vitro degradation. Among the developed films, CS/Gel/MgO films containing 1 wt. % of MgO NPs demonstrated an increased biocompatibility, bioactivity and cell migration ability. These results indicated that the porous films based on CS/Gel/MgO could be a competent dermal substitute for wound healing application.

Development of alveolar-capillary-exchange (ACE) chip and its application for assessment of PM2.5-induced toxicity

Although standard two-dimensional (2D) cell culture is an effective tool for cell studies, monolayer cultivation can yield imperfect or misleading information about numerous biological functions. In this study, we developed an alveolar-capillary exchange (ACE) chip aiming to simulate the cellular microenvironment at the alveolar-capillary interface. The ACE chip was designed with two chambers for culturing alveolar epithelial cells and vascular endothelial cells separately, which are separated by a microporous polycarbonate film that allows for the exchange of soluble biomolecules. Using this model, we further tested the toxic effects of fine particulate matter (PM2.5), a form of airborne pollutant known to induce adverse effects on human respiratory system. These effects are largely associated with the ability of PM2.5 to penetrate the alveoli, where it negatively affects the pulmonary function. Our results indicate that alveolar epithelial cells cultured in the ACE chip in solo and coculture with vascular endothelial cells underwent oxidative injury-induced apoptosis mediated via the PEAK-eIF2α signaling pathway of endoplasmic reticulum stress. The use of ACE chip in an alveolar epithelial cell-vascular endothelial cell coculture model revealed cellular vulnerability to PM2.5. Therefore, this chip provides a feasible surrogate approach in vitro for investigating and simulating the cellular microenvironment responses associated with ACE in vivo.

Microporous vanadosilicate films with tailorable V4+/V5+ ratio to achieve enhanced visible-light photocatalysis

This study investigates the changes induced into the photocatalytic activity under solar light irradiation upon changing the structural film properties and tailor the concentration of defects in microporous vanadosilicate AM-6 films. For this purpose, the preparation of AM-6 films with different V4+/V5+ ratios and their utilization as photocatalysts for the decomposition of MB were carried out. Two approaches were used for obtaining AM-6 films with different V4+/V5+ ratios: altering the seed layer coating technique and altering the molar water content of the secondary growth gel. It was seen that dip coating method resulted in an increase in the thickness of the films and it was presumed that the adsorption of MB by AM-6 films was the predominant factor in photocatalytic activity. The second approach of increasing the molar water content of the secondary growth gel provided an increase in the defect concentration resulting in an enhanced photocatalytic activity under the solar light. In the current study, the defect concentration of the prepared films was determined by using XPS and Raman spectroscopy techniques. Accordingly, it was determined that the samples with lower amount V4+/V5+ ratio showed better photocatalytic activity under the solar light irradiation indicating that V5+ cations are responsible for the photocatalytic activity under visible light irradiation. This work provides methods of production of microporous films showing photocatalytic activity under visible light without the requirement of any post-synthesis treatments.

Antiviral adsorption activity of porous silicon nanoparticles against different pathogenic human viruses

New viral infections, due to their rapid spread, lack of effective antiviral drugs and vaccines, kill millions of people every year. The global pandemic SARS-CoV-2 in 2019–2021 has shown that new strains of viruses can widespread very quickly, causing disease and death, with significant socio-economic consequences. Therefore, the search for new methods of combating different pathogenic viruses is an urgent task, and strategies based on nanoparticles are of significant interest. This work demonstrates the antiviral adsorption (virucidal) efficacy of nanoparticles of porous silicon (PSi NPs) against various enveloped and non-enveloped pathogenic human viruses, such as Influenza A virus, Poliovirus, Human immunodeficiency virus, West Nile virus, and Hepatitis virus. PSi NPs sized 60 nm with the average pore diameter of 2 nm and specific surface area of 200 m2/g were obtained by ball-milling of electrochemically-etched microporous silicon films. After interaction with PSi NPs, a strong suppression of the infectious activity of the virus-contaminated fluid was observed, which was manifested in a decrease in the infectious titer of all studied types of viruses by approximately 104 times, and corresponded to an inactivation of 99.99% viruses in vitro. This sorption capacity of PSi NPs is possible due to their microporous structure and huge specific surface area, which ensures efficient capture of virions, as confirmed by ELISA analysis, dynamic light scattering measurements and transmission electron microscopy images. The results obtained indicate the great potential of using PSi NPs as universal viral sorbents and disinfectants for the detection and treatment of viral diseases.

High hydrogen uptake by a metal-graphene-microporous carbon network

High-surface area carbon nanomaterials are promising candidate as reversible physisorption materials for hydrogen storage in personal transportation vehicles at moderate temperatures and pressures. Metal-incorporated graphitic microporous carbon is considered to be an excellent H2 storage material due to high molecular hydrogen uptake at the micropores coupled with considerable H2 adsorption at the graphitic network. A simple, cost-effective sputtering technique is adopted to fabricate metal-incorporated graphitic microporous carbon film and differential resistance measurements are carried out in H2 ambient to observe the high hydrogen uptake within the samples. Ultrathin amorphous carbon film is irradiated with metal nanoparticles which converts it into graphitic carbon, whereas sputtering plasma acts as dry-etchant to activate it into microporous carbon. Average number of graphene layer formation is observed to be dependent on sputtering parameters (current/voltage/time), which manifest bi-layer to multi-layer graphene sheets. With increase in the graphene layers, hydrogen adsorption also increases due to a four-fold effect - higher molecular hydrogen uptake at the graphene layers, more active sites into the micropores, promotion of molecular dissociation into atomic hydrogen by the metal nanoparticles, followed by adsorption at the active surface sites and the formation of hydrogenated carbon via destruction of the π-bonds.

Microporous Film of Ternary Ni/Co/Fe Alloy for Superior Electrolytic Hydrogen Production in Alkaline Medium

This study addresses the superb electrocatalytic activity of a ternary-alloy catalyst of Ni/Co/Fe towards the hydrogen evolution reaction (HER) in alkaline medium. The dynamic hydrogen bubbling template (DHBT) method was applied to electrodeposit the catalyst layer with unique microporous foam-like morphology. The electrodeposited Ni/Co/Fe microporous film was subsequently electropassivated by cycling the potential in 1.0 M KOH. The thus-prepared catalyst supports a HER current of 10 mA cm−2 at a significantly low overpotential of −50 mV in 1.0 M KOH (comparable to benchmarking catalysts) together with marked prolonged stability for 10 h of continuous operation at 100 mA cm−2. Interestingly, the electropassivation process was performed with an aim to enrich the surface of the Ni/Co/Fe film with metal/oxygenated metal interfaces that facilitate the retarding water dissociation step. The obtained results, herein, indicate that the designed Ni/Co/Fe film is a promising catalyst for alkaline HER and shed some light on the impact of the electropassivation process on the electrocatalytic activity towards alkaline HER. The morphology, composition, and crystal structure of the proposed catalysts were disclosed employing SEM, EDS mapping, HRTEM, ICP-OES, XRD, and XPS surface characterization techniques.

Microporous Oxide-Based Surface-Enhanced Raman Scattering Film for Quadrillionth Detection of Mercury Ion (II)

A variety of chemical sensing materials and procedures for conveniently detecting mercuric ion (II) (Hg2+) have been extensively explored. The detection challenges for accomplishing a simple, fast, and low investment procedure at the ultrasensitive level are ongoing. Herein we report a quadrillionth level for detecting Hg2+ by the surface-enhanced Raman scattering (SERS) technique. There is an interaction of silver nanoparticles decorated on a zinc-oxide tetrapod structure and coated on FTO glass (Ag@ZnO-FTO) with an organic ligand. 4,4′-Dipyridyl (DPy) performed as being chemisorbed by Ag nanoparticles interacting with a pyridine ring to produce plasmonic hot spots for SERS. The morphology of the surface and porous structure of the tetrapod becomes the powerful platform for enhanced SERS performance of DPy detection. In the absence of the augmentative electrolyte, the enhancement factor for DPy is more than 107. The inhibiting of the aggregation between Ag and DPy was present following the appearance of Hg2+, demonstrated by the quenching of the SERS signal from the DPy molecules. The capability to reproduce and the selectivity of the sensing by DPy were both demonstrated. In addition, the applications for detecting Hg2+ in natural water and beverages were successfully detected. These results demonstrated the SERS sensors had the potential for detecting Hg2+ in practical use.

Colorless and Transparent Polyimide Microporous Film with Excellent Physicochemical Property.

4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) as a dianhydride and bis(3-aminophenyl) sulfone (APS) and bis(3-amino-4-hydroxyphenyl) sulfone (APS-OH) as diamines were used to synthesize two types of poly(amic acid) (PAA). Varying amounts (0–5.0 wt%) of water-soluble poly(vinyl alcohol) (PVA) were mixed with PAA, and the resulting blend was heat-treated at different stages to obtain the colorless and transparent polyimide (CPI) blend films. The synthesized blended film completely removed water-soluble PVA in water. The possibility as a porous membrane according to the pore size varied according to the amount of PVA was investigated. The dispersibility and compatibility of CPI containing APS-OH monomer were higher than those of the APS monomer. This could be attributed to the hydrogen-bonding interactions between the CPI main chains and PVA. Scanning electron microscopy was conducted to characterize the material. The results revealed that the pore size of the CPI blend film increased as the PVA concentration increased. It was confirmed that uniform pores of μm-size were observed in CPI. The thermal stabilities, morphologies, optical properties, and solubilities of two CPIs obtained using APS and APS-OH monomers were investigated and their properties were compared with each other.

Simultaneous electrochemical determination of nitrophenol isomers Based on spirofluorene - based microporous polymer film modified electrodes through one-step electropolymerization strategy

A novel, convenient, and highly selective electrochemical sensor for simultaneous determination of nitrobenzene isomers based on conjugate microporous polyspirofluorene film modified glassy carbon electrodes (PSF/GCE) was established in this work, which was conducted on GCE through one-step co-electropolymerization for the first time. The proposed strategy exhibited outstanding electrocatalytic activity for the reduction of nitrophenol. Well identifiable redox peaks for each nitrobenzene isomer were obtained and their simultaneous detection can be received due to the high content of π - π orbital of spirofluorene - based conjugated microporous polymer film, which abundant electron significantly enhances the electrochemical response with electron-poor nitro-analytes. Related characterizations have confirmed its excellent electroactive surface area and analytical properties of the as-prepared sensor. Under the optimization conditions, the linear range of the sensor is from 0.1–100 μM for o-nitrophenol, 0.2–100 μM m-nitrophenol, and 0.1–120 μM for p-nitrophenol, while their minimal detection levels were 0.01 μM, 0.03 μM, and 0.01 μM, respectively. The modified electrode also revealed high selectivity, good reproducibility, and promising stability. More importantly, satisfactory recoveries were received for the developed sensor in the detection of target nitrophenol isomers, which exhibited a broad prospect in practical application.

Regulating the mechanical properties and microporous structures of hydroxypropyl methylcellulose based microporous photophobic films by adjusting the l-ethyl-3-methylimidazolium acetate content

X-ray diffraction, small angel X-ray scattering, scanning electron microscopy, moisture determination, dynamic mechanical analysis, whiteness assay and mechanical testing were used to study the effects of different doses of [EMIM]Ac on the microstructures and physical properties of HPMC/MSP film. By adjusting the 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) content (0 %–8 %), the mechanical properties and microstructures could be regulated. The elongation of the film increased from 5.91 % to 12.83 % with the increasing [EMIM]Ac content from 0% to 8% without affecting the tensile strength and modulus significantly. The average pore area decreased from 0.82 μm2 to 0.05 μm2 and the pore number increased with the increasing [EMIM]Ac content from 0% to 8%. Moreover, with the increasing [EMIM]Ac content, Tg decreased. 6% and 8% [EMIM]Ac decreased the compactness and smoothness of the fractal structure of the film greatly. [EMIM]Ac improved the ductility of HPMC/MSP film, which was mainly due to the decreased pore size and Tg. The improved photophobic films are both flexible and with easily changeable porous structure, which can be used as controllable packaging to carry and control-release different functional agents for different light sensitive foods.

Tailoring ultrathin microporous polyamide films with rapid solvent transport by molecular layer-by-layer deposition

In this work, a new molecular layer-by-layer deposition (MLD) approach was demonstrated to tailor thin-film composite (TFC) membranes with ultrathin microporous polyamide (PA) films as separation layers used for organic solvent nanofiltration (OSN). The extrinsic and intrinsic microstructures of the crosslinked PA layers were synergistically tailored by the layer-by-layer reaction between rigid tri-amine monomer 1,3,5-tris(4-aminophenyl)benzene (TAPB) with trimesoyl chloride (TMC). The thickness of defect-free PA layers, which exhibited a homogeneous cross-sectional morphology, was decreased down to 26 nm by regulating the deposition cycles, which is advantageous to achieve high solvent permeability. Moreover, the generated PA layers displayed high microporosity (specific surface area up to 114 m2 g−1) due to the rigid polyphenyl tri-amine structure of TAPB monomer. These characteristics conferred upon the prepared TFC membranes with exceptional solvent permeabilities (5.5, 5.0, 14.6, and 39.8 L m−2 h−1 bar−1 for ethanol, dimethyl formamide, methanol, and acetonitrile, respectively) and high rejection (93.2%) towards methyl orange (327 Da of molecular weight), all of which are higher than those of the majority of state-of-the-art TFC membranes using PA or other newly porous materials (e.g., polyacrylates, polymers of intrinsic microporosity-1) as separation layers. Furthermore, the membranes showed excellent solvent and pressure resistance due to highly cross-linking network character. Given the noticeable advantages of this method, a new alternative for preparing high-performance TFC OSN membranes can be provided.

Continuous DLP-based ceramic 3D printing using a composite oxygen-rich film

The existing stereolithography-based ceramic 3D printing techniques are noncontinuous in a layer-by-layer method, which usually causes drawbacks of anisotropic mechanical properties, stair-casing effect, and the low fabrication rate. In this paper, a continuous DLP-based ceramic 3D printing is proposed to achieve the layerless ceramic manufacturing. In order to achieve this goal, a composite oxygen-rich film was designed with a microporous PET film and a PDMS coating to ensure a proper dead zone thickness according to the oxygen-controlled inhibition effect and low surface energy for releasing quickly from ceramic slurry. And a ceramic slurry with low viscosity was also prepared to match it. Then, the effects of influencing factors including the composite oxygen-rich film, ceramic slurry, and the print speed on the printing quality and geometrical overgrowth have been investigated. It shows that the geometrical overgrowth has a good linear relationship with this variable, the larger dead zone thickness, the higher solid content, and the low print speed, the larger the geometrical overgrowth. And the print speed does not worsen the surface quality. This proposed method can achieve the maximum speed of 143 mm/h and a surface roughness of 0.127 for a 40 vol% ceramic slurry. To demonstrate the utility of this system, parts of hollow structure, thin wall structure, and impeller structure have been successfully printed and sintered to ceramics with a condensed and porous structure. As a result, the proposed continuous DLP-based ceramic 3D printing technique provides a promising solution for ceramic 3D printing.

Rational synthesis and characterization of IL-CNTs-PANI microporous polymer electrolyte film

A noble, safe and electrochemically stable microporous IL-CNTs-PANI polymer electrolyte has been reported. In the microporous polymer electrolyte (MPE), polyvinylidene fluoride (PVDF) was doped with an ionic liquid (IL), carbon nanotubes (CNTs) and polyaniline (PANI). The surface structure and element composition of MPE film were measured by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and fourier-transform infrared spectroscopy (FTIR). The thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) have carried out to characterize electrolytes’ thermal stability, and the electrochemical performance was measured by cyclic voltammetry (CV) and Tafel curves. It is found that a soft and porous MPE film can be obtained by changing the content of CNTs/PANI and the heat treatment temperature. Doping with different amounts of PANI has certain effects on the thermal stability and crystallization properties of MPE film. The prepared electrolyte membrane has good capacitance, wide electrochemical window (~3 V), certain charge transfer and ionic conductivity. Finally, the prepared electrolyte membrane was used to print a NO2 gas sensor, which proved that the MPE has the potential to become a gas-sensing material for NO2 sensors.

In situ investigation of formation kinetics of microporous structure in PVDF thin films prepared via thermally‐induced phase separation (TIPS): Effects of film thickness and polymer concentration

AbstractIn this research, series of PVDF microporous films with various polymer concentrations and thickness were prepared through thermally‐induced phase separation in air condition with diphenyl carbonate as the diluent. Effects of polymer concentration and film thickness on the formation kinetics of microporous structure of PVDF thin films were in situ investigated via TII technique. The instantaneous heat conduction inside the films during film formation was also evaluated. Two types of parameter models were adopted in order to disclose the time and location dependence of TIPS film solidification kinetics, respectively. Hierarchical microstructures, crystallization behavior and thermal properties of the TIPS films were also characterized by SEM, DSC, and TGA, respectively. The current study could supply an insight into the fabrication of PVDF microporous films with target microstructure and desirable performance.

Fabrication of PAN/Ag/ZnO Microporous Membrane and Examination of Visible Light Photocatalytic Performance

In the paper, a novel polyacrylonitrile/Ag/ZnO (PAN/Ag/ZnO) microporous membrane was prepared by sequential electrospinning, chemical silver plating and hydrothermal reaction. Morphology and structure of PAN/Ag/ZnO membrane and the photocatalytic performance of Rhodamine Bsolution under visible-light irradiation were systematically investigated. It was found that ZnO nanorod and ZnO nanosheet with hexagonal wurtzite structure were prepared in different concentration of growth solution. The visible light photocatalytic performance test showed that ZnO nanorod had higher photocatalytic efficiency than ZnO nanosheet. After 6 hours of irradiation, the degradation efficiency of the RhB solution of PAN/Ag/ZnO film with only 2 mg of ZnO nanorods reached 98%. After 5 times of repeated experiments, there was no notable decrease in the performance. The photocatalytic performance of the material is enhanced by chemical silver plating. Compared with the unsilvered samples, the addition of Ag not only made the microporous film grow more ZnO, but also greatly improved the visible light photocatalytic performance by forming Ag-ZnO metal-semiconductor interface.

Facile way of dynamically tailoring microporous structures in polyvinylidene fluoride films prepared by thermally induced phase separation

AbstractPolyvinylidene fluoride (PVDF) films were prepared via thermally induced phase separation (TIPS) using diphenyl carbonate as the diluter in an attempt to disclose the competitive relationship between crystal growth and droplet growth during phase separation process. By varying the quenching temperature different temperature gradient fields were established, which were theoretically evaluated via enthalpy transformation method. The effects of polymer concentration and quenching temperature on evolution of hierarchical morphologies in TIPS films were systematically investigated. According to the morphological characteristics, the cross‐sectional morphology of the films with lower polymer concentration (ΦP = 25%) could be divided into three layers; while that of higher polymer concentration counterpart (ΦP = 55%) only presented a bi‐layered structure. The reason for this could be ascribed to the effect of cooling rate on both crystal growth and droplet growth during TIPS process, which further determined the formation of the hierarchical structure in microporous films. With an increasing quenching temperature, both pore size and porosity of PVDF films increased, accompanied by an improvement on both thermal stability and dynamic mechanical thermal property. The present study could insightfully supply a facile route to fabricate structure‐controllable microporous films of crystalline polymers via an appropriate regulation of the TIPS quenching parameters.