Thermally Induced Phase Separation Research Articles

3D printed polylactic acid (PLA) filters reinforced with polysaccharide nanofibers for metal ions capture and microplastics separation from water

The need for multifunctional, robust, reusable, and high-flux filters is a constant challenge for sustainable water treatment. In this work, fully biobased and biodegradable water purification filters were developed and processed by the means of three-dimensional (3D) printing, more specifically by fused deposition modelling (FDM).The polylactic acid (PLA) – based composites reinforced with homogenously dispersed TEMPO-oxidized cellulose nanofibers (TCNF) or chitin nanofibers (ChNF) were prepared within a four-step process; i. melt blending, ii. thermally induced phase separation (TIPS) pelletization method, iii. freeze drying and iv. single-screw extrusion to 3D printing filaments. The monolithic, biocomposite filters were 3D printed in cylindrical as well as hourglass geometries with varying, multiscale pore architectures. The filters were designed to control the contact time between filter’s active surfaces and contaminants, tailoring their permeance.All printed filters exhibited high print quality and high water throughput as well as enhanced mechanical properties, compared to pristine PLA filters. The improved toughness values of the biocomposite filters clearly indicate the reinforcing effect of the homogenously dispersed nanofibers (NFs). The homogenous dispersion is attributed to the TIPS method. The NFs effect is also reflected in the adsorption capacity of the filters towards copper ions, which was shown to be as high as 234 and 208 mg/gNF for TCNF and ChNF reinforced filters, respectively, compared to just 4 mg/g for the pure PLA filters. Moreover, the biocomposite-based filters showed higher potential for removal of microplastics from laundry effluent water when compared to pure PLA filters with maximum separation efficiency of 54 % and 35 % for TCNF/PLA and ChNF/PLA filters, respectively compared to 26 % for pure PLA filters, all that while maintaining their high permeance.The combination of environmentally friendly materials with a cost and time-effective technology such as FDM allows the development of customized water filtration systems, which can be easily adapted in the areas most affected by the inaccessibility of clean water.

Structure-property relationships in PCL porous scaffolds obtained by means of the TIPS and TIPS-PL methods

This study aims at characterization of porous poly(ε-caprolactone) (PCL) scaffolds prepared by the methods of thermally induced phase separation (TIPS) and TIPS supported by particulate leaching (PL). Both techniques were combined with freeze-drying. Two PCL grades (with different average molecular weight characterized by MFR 6.1 and 1.2 g/10 min) were employed in the fabrication of scaffolds. Three types of salt (sodium chloride) particles were used in the TIPS-PL preparation of the PCL sample: (i) smaller particles (S) measuring 200–315 μm, (ii) larger particles (B) measuring 500–600 μm, and (iii) mixture of S and B particles (S/B = 1/1 wt/wt). The crystallization behavior of the PCL solutions and the thermal properties of scaffolds were investigated by polarized light microscopy (PLM) and differential scanning calorimetry (DSC), respectively. The structural changes of PCL were studied by attenuated total reflectance infrared spectroscopy (ATR-FTIR). The scaffold structure was visualized by means of scanning electron microscopy (SEM) and X-Ray micro-computed tomography (X-ray micro-CT). Furthermore, the density, porosity, water uptake, contact angle and compressive properties of scaffold were investigated. The molecular weight of PCL had an impact on the crystallization of the PCL solutions and thereby on the crystallinity of scaffolds and the morphology of pore walls formed during TIPS. Sodium chloride grains had an influence on the pore size and overall morphology of foam scaffolds prepared by TIPS-PL. The addition of NaCl decreased significantly the density and compressive properties and increased the porosity and water uptake of scaffolds.

Fluoropolymer Membranes for Membrane Distillation and Membrane Crystallization.

Fluoropolymer membranes are applied in membrane operations such as membrane distillation and membrane crystallization where hydrophobic porous membranes act as a physical barrier separating two phases. Due to their hydrophobic nature, only gaseous molecules are allowed to pass through the membrane and are collected on the permeate side, while the aqueous solution cannot penetrate. However, these two processes suffer problems such as membrane wetting, fouling or scaling. Membrane wetting is a common and undesired phenomenon, which is caused by the loss of hydrophobicity of the porous membrane employed. This greatly affects the mass transfer efficiency and separation efficiency. Simultaneously, membrane fouling occurs, along with membrane wetting and scaling, which greatly reduces the lifespan of the membranes. Therefore, strategies to improve the hydrophobicity of membranes have been widely investigated by researchers. In this direction, hydrophobic fluoropolymer membrane materials are employed more and more for membrane distillation and membrane crystallization thanks to their high chemical and thermal resistance. This paper summarizes different preparation methods of these fluoropolymer membrane, such as non-solvent-induced phase separation (NIPS), thermally-induced phase separation (TIPS), vapor-induced phase separation (VIPS), etc. Hydrophobic modification methods, including surface coating, surface grafting and blending, etc., are also introduced. Moreover, the research advances on the application of less toxic solvents for preparing these membranes are herein reviewed. This review aims to provide guidance to researchers for their future membrane development in membrane distillation and membrane crystallization, using fluoropolymer materials.

Biodegradable Mulching Films Based on Polycaprolactone and Its Porous Structure Construction.

Polycaprolactone (PCL) is one of the promising linear aliphatic polyesters which can be used as mulching film. Although it has suitable glass transition temperature and good biodegradability, further practical applications are restricted by the limited temperature-increasing and moisturizing properties. The rational design of the PCL structure is a good strategy to enhance the related properties. In this study, thermally-induced phase separation (TIPS) was introduced to fabricate a PCL nanoporous thin film. The introduction of a nanoporous structure on the PCL surface (np-PCL) exhibited enhanced temperature-increasing and moisturizing properties when used as mulch film. In detail, the average soil temperature of np-PCL was increased to 17.81 °C, when compared with common PCL of 17.42 °C and PBAT of 17.50 °C, and approaches to PE of 18.02 °C. In terms of water vapor transmission rate, the value for np-PCL is 637 gm-2day-1, which was much less than the common PCL of 786 and PBAT of 890 gm-2day-1. As a result, the weed biomass under the np-PCL was suppressed to be 0.35 kg m-2, almost half of the common PCL and PBAT. In addition, the np-PCL shows good thermal stability with an onset decomposition temperature of 295 °C. The degradation mechanism and rate of the np-PCL in different pH environments were also studied to explore the influence of nanoporous structure. This work highlights the importance of the nanoporous structure in PCL to enhance the temperature-increasing and moisturizing properties of PCL-based biodegradable mulching film.

Preparation of Chemically Resistant Cellulose Benzoate Hollow Fiber Membrane via Thermally Induced Phase Separation Method.

For the first time, we have successfully fabricated microfiltration (MF) hollow fiber membranes by the thermally induced phase separation (TIPS) and non-solvent induced phase separation (NIPS) methods using cellulose acetate benzoate (CBzOH), which is a cellulose derivative with considerable chemical resistance. To obtain an appropriate CBzOH TIPS membrane, a comprehensive solvent screening was performed to choose the appropriate solvent to obtain a membrane with a porous structure. In parallel, the CBzOH membrane was prepared by the NIPS method to compare and evaluate the effect of membrane structure using the same polymer material. Prepared CBzOH membrane by TIPS method showed high porosity, pore size around 100 nm or larger and high pure water permeability (PWP) with slightly low rection performance compared to that by NIPS. On the contrary, CBzOH membranes prepared with the NIPS method showed three times lower PWP with higher rejection. The chemical resistance of the prepared CBzOH membranes was compared with that of cellulose triacetate (CTA) hollow fiber membrane, which is a typical cellulose derivative as a control membrane, using a 2000 ppm sodium hypochlorite (NaClO) solution. CBzOH membranes prepared with TIPS and NIPS methods showed considerable resistance against the NaClO solution regardless of the membrane structure, porosity and pore size. On the other hand, when the CTA membrane, as the control membrane, was subjected to the NaClO solution, membrane mechanical strength sharply decreased over the exposure time to NaClO. It is interesting that although the CBzOH TIPS membrane showed three times higher pure water permeability than other membranes with slightly lower rejection and considerably higher NaClO resistance, the mechanical strength of this membrane is more than two times higher than other membranes. While CBzOH samples showed no change in chemical structure and contact angle, CTA showed considerable change in chemical structure and a sharp decrease in contact angle after treatment with NaClO. Thus, CBzOH TIPS hollow fiber membrane is noticeably interesting considering membrane performance in terms of filtration performance, mechanical strength and chemical resistance on the cost of slightly losing rejection performance.

Ammonia removal using thermally induced phase separation PVDF hollow fibre membrane contactors

Hollow fibre membrane contactors (HFMCs) are a promising new technology for ammonia recovery but are limited by the mass transfer efficiency as well as their chemical resistance and physical strength. Thermally Induced Phase Separation (TIPS) Polyvinylidene Fluoride (PVDF) membranes offer a new HFMC option for ammonia recovery due to their superior removal performance and physicochemical properties. In this study, two chemically robust TIPS PVDF HFMCs were synthesized and evaluated for the recovery of ammonia from wastewater. The HFMCs displayed an uncompromised high tensile strength of up to 19.12 ± 0.93 MPa under a long-term chemical exposure against acids, alkalis, and oxidants over 60 days of immersion. The HFMCs had a high air permeance flux of up to 1.67 ± 0.26 mol/m2/s. The crystalline structure of the TIPS PVDF membranes affected the hydrophobicity of the membranes more than pore size. Optimisation of ammonia removal was achieved by the Taguchi method for design of experiments using five operational parameters namely pH, temperature, ammonia solution velocity, concentration, and air sparging rate. Empirical evidence showed that the TIPS PVDF HFMCs achieved the highest ammonia removal of greater than 99% and a mass transfer coefficient (Kov) of up to 4.53 × 10-5 m/s. Comparatively, the Kov and flux of both TIPS PVDF membranes in this study are up to one order higher than those previously reported and could even be higher with further improvements to operating conditions. Air sparging is for the first time used in HFMCs to improve ammonia removal and is known to simultaneously reduce membrane fouling.

Development of organic solvent-induced shape memory poly(ethylene-co-vinyl acetate) monoliths for expandable oil absorbers

In this work, organic solvent-induced shape memory poly(ethylene-co-vinyl acetate) (EVA) monoliths are developed based on a facile thermally induced phase separation (TIPS) method. The obtained EVA monoliths show three-dimensional (3D) interconnected porous structures with tunable porosities from 54.52 % to 73.01 %, average pore sizes from 4.8 to 17.5 μm, and satisfactory shape memory properties. Utilizing the hydrophobic nature of EVA, the porous monoliths effectively separate oil/water by selective oil absorption. Moreover, the EVA monoliths exhibiting oil-triggered shape recovery are designed to be expandable oil absorbers, which shows doubled volumetric absorption capacities of 1.96–2.48 g/cm3 for pentane, hexane, and octane with a prefixed compression strain of 70 %. The uniform porous structures of monolithic materials and shape memory properties of semi-crystalline elastomers are well combined in this work, which will provide new possibilities for the design of smart porous materials or structures for novel oil absorbers, thermal insulators, and flow reactors.

Current State-of-the-Art in Membrane Formation from Ultra-High Molecular Weight Polyethylene.

One of the materials that attracts attention as a potential material for membrane formation is ultrahigh molecular weight polyethylene (UHMWPE). One potential material for membrane formation is ultrahigh molecular weight polyethylene (UHMWPE). The present review summarizes the results of studies carried out over the last 30 years in the field of preparation, modification and structure and property control of membranes made from ultrahigh molecular weight polyethylene. The review also presents a classification of the methods of membrane formation from this polymer and analyzes the conventional (based on the analysis of incomplete phase diagrams) and alternative (based on the analysis of phase diagrams supplemented by a boundary line reflecting the polymer swelling degree dependence on temperature) physicochemical concepts of the thermally induced phase separation (TIPS) method used to prepare UHMWPE membranes. It also considers the main ways to control the structure and properties of UHMWPE membranes obtained by TIPS and the original variations of this method. This review discusses the current challenges in UHMWPE membrane formation, such as the preparation of a homogeneous solution and membrane shrinkage. Finally, the article speculates about the modification and application of UHMWPE membranes and further development prospects. Thus, this paper summarizes the achievements in all aspects of UHMWPE membrane studies.

The Design of 3D-Printed Polylactic Acid-Bioglass Composite Scaffold: A Potential Implant Material for Bone Tissue Engineering.

Bio-based and patient-specific three-dimensional (3D) scaffolds can present next generation strategies for bone tissue engineering (BTE) to treat critical bone size defects. In the present study, a composite filament of poly lactic acid (PLA) and 45S5 bioglass (BG) were used to 3D print scaffolds intended for bone tissue regeneration. The thermally induced phase separation (TIPS) technique was used to produce composite spheres that were extruded into a continuous filament to 3D print a variety of composite scaffolds. These scaffolds were analyzed for their macro- and microstructures, mechanical properties, in vitro cytotoxicity and in vivo biocompatibility. The results show that the BG particles were homogeneously distributed within the PLA matrix and contributed to an 80% increase in the mechanical strength of the scaffolds. The in vitro cytotoxicity analysis of PLA-BG scaffolds using L929 mouse fibroblast cells confirmed their biocompatibility. During the in vivo studies, the population of the cells showed an elevated level of macrophages and active fibroblasts that are involved in collagen extracellular matrix synthesis. This study demonstrates successful processing of PLA-BG 3D-printed composite scaffolds and their potential as an implant material with a tunable pore structure and mechanical properties for regenerative bone tissue engineering.

Influence of rGO on the Crystallization Kinetics, Cytoxicity, and Electrical and Mechanical Properties of Poly (L-lactide-co-ε-caprolactone) Scaffolds.

Biodegradable scaffolds of poly (L-lactide-co-ε-caprolactone) (PLCL) and reduced graphene oxide (rGO) were prepared by TIPS (thermally induced phase separation). The nonisothermal cold crystallization kinetics were investigated by differential scanning calorimetry (DSC) with various cooling rates. The experimental values indicate that nonisothermal crystallization improves with cooling rate, but the increasing rGO concentration delays crystallization at higher temperatures. The activation energies were calculated by the Kissinger equation; the values were very similar for PLCL and for its compounds with rGO. The electrical conductivity measurements show that the addition of rGO leads to a rapid transition from insulating to conductive scaffolds with a percolation value of ≈0.4 w/w. Mechanical compression tests show that the addition of rGO improves the mechanical properties of porous substrates. In addition, it is an anisotropic material, especially at compositions of 1% w/w of rGO. All of the samples with different rGO content up to 1% are cytotoxic for C2C12 myoblast cells.

Rapid, linear, and highly reliable structural-color switching enabled by thermal regulation of chiral nematic mesophases

Bioinspired dynamic structural-colored materials have shown wide applications in sensing, display, information encryption and security. However, because of restrictions of design principles, it remains a big challenge to break limitations of color control, color-changing rate, and repeatability. Here, we demonstrate fast, linear, and reliable structural-color modulations with a one-component chiral nematic mesophase following a thermally-induced phase separation mechanism. Molecular dynamic simulation reveals that the hydrogen bonding tunability between the mesophase and solvent dominates the fast and reversible phase transition behaviors that account for the fast and repeatable color responses. The photonic crystal displays wide-range (red-to-purple) colorations by controlling the mesophase concentration and external temperature. Due to the linear change of turbidity upon temperature stimuli, linearly programmable color regulations are enabled without color hysteresis. These features allow the development of multi-functional devices with applications for portable sensors, painting decoration, and information security encryption.

Janus ZIF-8/P(AN-MA) hybrid microfiltration membrane with selected wettability for highly efficient separation of water/oil emulsions

The separation of oil-in-water and water-in-oil emulsions with high efficiency and environmental friendly remains a challenge in the past decade. This work describes a new method to improve the trade-off of the poly(acrylonitrile-co-methyl acrylate) (P(AN-MA))-based membrane for water/oil separation. P(AN-MA) microfiltration (MF) membrane was fabricated via thermally induced phase separation (TIPS) method in this study. Then, some of the –CN groups and –COOCH3 groups were converted to –COOH groups via hydrolyzing. Finally, the selected wettability was attained by grafting PEI on one side while ZIF-8 was anchored to the other side via self-assembly and in-situ interfacial reaction methods. The ZIF-8/P(AN-MA) hybrid MF membranes are superoleophobic underwater on the PEI side while super-hydrophobic under oil on the ZIF-8 side, which can efficiently and accurately separate oil-in-water and water-in-oil emulsions at a low pressure (0.01 MPa). The separation fluxes of the PEI side were as high as 3053 L/m2 h and 1035 L/m2 h respectively, for the surfactant-free mixtures and surfactant-stabilized emulsions. For water-in-oil emulsions, the fluxes were up to 2316 L/m2 and 878 L/m2 h on the ZIF-8 side, respectively. The separation efficiency of all the mixtures and emulsions was higher than 97.5 %. Moreover, the Janus membranes showed excellent anti-oil-fouling and anti-water-fouling properties on the two sides of the membranes, as well as remarkable durability during the 10 cycles in oil/water separation. Hence, Janus ZIF-8/P(AN-MA) hybrid MF membranes show potential application prospects in oil/water separation.

Treating Waste with Waste: Facile Preparation of Elastic Thermoplastic Polyurethane Monolith for Efficient Oil/Water Separation

Abstract An auspicious thermoplastic polyurethane (TPU) monolith has been prepared by a facile and cost-effective method of thermally induced phase separation (TIPS). With superb porous structure, excellent hydrophobicity/oleophilicity, and superior elasticity, the obtained TPU monolith exhibits an outstanding adsorption capacity, high oil/water separation efficiency, and good recycling performance, achieving the goal of treating waste with waste.

Preparation of Microfiltration Hollow Fiber Membranes from Cellulose Triacetate by Thermally Induced Phase Separation.

For the first time, self-standing microfiltration (MF) hollow fiber membranes were prepared from cellulose triacetate (CTA) via the thermally induced phase separation (TIPS) method. The resultant membranes were compared with counterparts prepared from cellulose diacetate (CDA) and cellulose acetate propionate (CAP). Extensive solvent screening by considering the Hansen solubility parameters of the polymer and solvent, the polymer’s solubility at high temperature, solidification of the polymer solution at low temperature, viscosity, and processability of the polymeric solution, is the most challenging issue for cellulose membrane preparation. Different phase separation mechanisms were identified for CTA, CDA, and CAP polymer solutions prepared using the screened solvents for membrane preparation. CTA solutions in binary organic solvents possessed the appropriate properties for membrane preparation via liquid–liquid phase separation, followed by a solid–liquid phase separation (polymer crystallization) mechanism. For the prepared CTA hollow fiber membranes, the maximum stress was 3–5 times higher than those of the CDA and CAP membranes. The temperature gap between the cloud point and crystallization onset in the polymer solution plays a crucial role in membrane formation. All of the CTA, CDA, and CAP membranes had a very porous bulk structure with a pore size of ∼100 nm or larger, as well as pores several hundred nanometers in size at the inner surface. Using an air gap distance of 0 mm, the appropriate organic solvents mixed in an optimized ratio, and a solvent for cellulose derivatives as the quench bath media, it was possible to obtain a CTA MF hollow fiber membrane with high pure water permeance and notably high rejection of 100 nm silica nanoparticles. It is expected that these membranes can play a great role in pharmaceutical separation.

Tunable all-in-one bimodal porous membrane of ultrahigh molecular weight polyethylene for solar driven interfacial evaporation

Solar driven interfacial evaporation is a promising technology to produce freshwater by clean energy source. Rational design of the porous structure of photothermal membranes for efficient energy conversion and vapor generation in long-term use is a key challenge. Herein, tunable all-in-one bimodal porous membrane of ultrahigh molecular weight polyethylene with interconnected porous network is first designed, which can effectively regulate porous structure by thermal-induced phase separation and NaCl-templet leaching. Carboxylated carbon nanotubes are evenly dispersed and embedded in the pore walls, efficiently absorbing solar energy and converting it into heat, exhibiting a satisfactory solar absorptance nearly 96 % and photothermal conversion efficiency about 96.3 %. Particularly, polydopamine is allowed to enter the porous membrane and deposit on the surface of the pore walls for water transport and water activation by flowing deposition, achieving water evaporation rate of 1.53 kg m−2h−1 at ∼97.6 % energy efficiency under 1 sun illumination. The membrane with lightweight, high porosity and abundant porous structure is able to stably desalinate in both 3.5 wt% and 10 wt% saline due to quick water exchange that suppresses salt crystallization during evaporation. This bimodal porous structure design is generic and can be expanded to other photothermal systems for advanced solar-thermal applications.

Fabrication of PVDF/EVOH blend hollow fiber membranes with hydrophilic property via thermally induced phase process

In this study, thermally induced phase separation (TIPS) technology was used to fabricate the PVDF/EVOH blend hollow fiber membranes using water-soluble mixed diluents. An interconnected bulk structure was formed by L-L phase separation for both the pristine membrane and blend membrane. The surface enrichment for EVOH during the cooling process enhanced the hydrophilicity of prepared hollow fiber membranes. It was found that the tensile strength of the blend membrane significantly increased from 2.6 MPa to 8.8 MPa. The variation of the membrane structure made the water permeability increase from 60 L m−2 h−1 bar−1 to 287 L m−2 h−1 bar−1 for the optimized blend membrane. Compared with the pristine membrane, EVOH blend membrane exhibited higher antifouling properties for BSA, HA, and oil-in-water emulsion filtrations.

Bone tissue engineering via application of a PCL/Gelatin/Nanoclay/Hesperetin 3D nanocomposite scaffold

Presence of a structure the same as extracellular matrix (ECM) is necessary for cells to improve healing in injured bone. For this reason, discovering appropriate materials and fabrication methods for making this structure called scaffold is a challenge in tissue engineering. In this study, the 3-D scaffold was made of Polycaprolactone/Gelatin/Nanoclay (PCL/Gel/NC) and various dosages of Hesperetin (Hes) were loaded by a combination of electrospinning and thermally-induced phase separation (TIPS) methods. Different experiments like evaluation of surface microstructure, porosity, compressive strength, water contact angle, degradation rate, releasing profile, hemolysis, and cell proliferation were done to assess attributes of fabricated scaffolds. For in vivo evaluation, the calvaria defect model in rats was used and its result was evaluated by histological analysis. Based on the results, the porosity of scaffolds was in the range of 70–90%, and samples containing Hesperetin had lower compress strength and contact angle and higher degradation rate in comparison with samples without Hesperetin. The results showed that PCL/Gel/NC/Hes1% had better cell proliferation and bone healing than other studied groups. The results of this study can be considered for further research to evaluate the effect of Hesperetin in bone healing.

Automatic pore size measurements from scanning electron microscopy images of porous scaffolds

Pore sizes and distribution are amongst the main morphological characteristics of porous scaffolds which indicate the suitability of scaffolds for many biological applications. Scaffolds usually have complex structures and are designed to have a specific range of pore sizes appropriate for target cells. Pore sizes are commonly estimated manually or based on semi-automatic techniques requiring high level of human intervention. Such methods are time consuming and subject to error, mainly due to lack of consistency in the process and subjective nature of the results following operator involvement. In this work, we present a novel image processing method for the measurement pore size distribution (the main morphological characteristics of scaffolds) independent from their complexity. We use thresholding, based on the histogram analysis, to segment pore areas from scaffold, followed by morphological filters to separate pores from each other. This algorithm provides robust detection and measurement of pore sizes and the distribution. The performance of the algorithm is assessed using standard calibration kit which is used for calibration of Scanning Electron Microscopy (SEM) imaging systems. The results showed consistent output with 1.3% average error as compared against their true size.The algorithm was applied to 3D Apatite-Wollastonite scaffolds manufactured using the Thermally Induced Phase Separation technique. The results were robust and consistent with visual evaluation of SEM images. The algorithm also provides the morphology of each pore and, subsequently, offering further comprehension of the influence of microstructures across a range of fields, such as tissue engineering processes.

Preparation of 4-methyl-1-pentene membranes via non-solvent induced phase separation (NIPS)

Poly 4-methyl-1-pentene (PMP) membranes are often used in gas separation and membrane oxygenators in extracorporeal membrane oxygenation (ECMO). Considering the high energy consumption of thermally induced phase separation (TIPS) method, in this article, PMP membranes were prepared via non-solvent induced phase separation (NIPS) under wide preparation conditions. The phase separation behavior of PMP/cyclohexane/alcohol system, effects of non-solvent additive in casting solution, evaporation temperature (0 ℃ − 60 ℃), evaporation time and coagulation temperature (-10 ℃ − 20 ℃) on the membrane structure and air permeability of PMP membranes were studied. The results showed that, the addition of appropriate amount of non-solvent to the casting solution effectively improved the air permeability. The evaporation step at low temperature led to robust membranes with high air permeability. Extending the evaporation time of the wet membranes increased the mechanical strength and air permeability. The lower coagulation temperature also contributed to a higher air permeability. The prepared PMP membranes showed great promises for applications in membrane oxygenators.

Application of Fourier’s law in thermally induced phase separation (TIPS) process for porous poly(L-lactide) films

Application of Fourier’s law in thermally induced phase separation (TIPS) process for porous poly(L-lactide) films