Hydrophobic Agents Research Articles

All-natural, hydrophobic, biodegradable cellulose-based straws through simultaneous esterification and filling with stearic acid for cold beverages.

Disposable plastic straws have caused severe environmental pollution because microplastics produced in the degradation process harm human health and marine ecosystems. Paper straws as substitutes need to be incorporated into hydrophobic agents and other chemicals to achieve hydrophobicity, which may be harmful to human health. In this study, a novel and purely natural hydrophobic cellulose-based straw was made from bleached bamboo fibers (BBF) and stearic acid (SA). The prepared straw (BBF/SA@straw) exhibited improved hydrophobicity, biodegradability, and applicability. The water absorption rate was maintained at 58.66 % using single-factor analysis and response surface methodology and the maximum water contact angle was up to 133o. Additionally, the paper straw was almost completely degraded after 50 days in soil. Moreover, it could be used normally in water at 0 °C and 25 °C and was suitable for various beverages (tea, coffee, coke, and milk), demonstrating an extensive application prospect. This work supplies a promising and green alternative to plastic straws, alleviating the burden of white pollution in the environment.

Co-loading Radio-photosensitizer Agents on Polymer and Lipid-based Nanocarriers for Radio-photodynamic Therapy Purposes: Review.

Polymer and lipid-based nanocarriers are a state-of-art in nanomedicine and in co-drug delivery of drugs that could merges various diagnostic and treatment modalities such radiotherapy (RT), photodynamic therapy (PDT) and chemotherapy (CT) in cancer therapy. Among various shapes and nanostructures, polymer and lipid-based nanocarriers have the potential to carry two drugs in same time to cells. However, hydrophobic and hydrophilic drug can be loaded in between layers as well as in the core of these nanocarriers, simultaneously. This advantage of NPs can be employed in combination therapy. Radiosensitizer and photosensitizer agents play a critical role in radio-photodynamic therapy (RT-PDT) of cancer. Co-delivery of these agents to cancerous cells is advantageous to cancer therapy but still remain as a challenge of RT-PDT. However, in this review, we have highlighted the challenges of RT-PDT and role of polymer and lipid-based nanocarriers to codelivery of hydrophobic and hydrophilic agents as radio-photosensitizers. Hence, the different kinds of Poly (lactic-co-glycolic acid) nanoparticles (NPs) have been categorized. Then, the biophysical mechanism of radio- photosensitizer agents with co-loading on polymer and lipid-based nanocarriers in RT-PDT treatment of cancer has been outlined. Finally, attention has been drawn to polymer and lipid-based nanocarriers in codrugs delivery. Taken together, this work presents the latest updates on this area and highlighted the pros and cons of co-delivery for RT-PDT purposes.

A Review on the Utilization of Epicuticular Wax from Plant Samples as a Hydrophobic Surface Coating Agent

A Review on the Utilization of Epicuticular Wax from Plant Samples as a Hydrophobic Surface Coating Agent

Induction of multicomponent peptide assembly via solvent exchange strategy for enhanced structure and bioactivities

Multicomponent peptides, composed of numerous peptides with various binding sites and functionalities, are increasingly exploited in nanotechnology, biomedicine and functional food applications. This article reported that nucleation and growth of Zein (Z) during solvent exchange could form a confined space to drive spontaneous self-assembly of multicomponent peptides. The self-assembly process began with a concentration gradient generated by the exchange of water and ethanol driving the nucleation of Z to form small aggregates, while multicomponent peptides selectively or anisotropically adsorbed on the Z surface via electrostatic interactions and hydrophobic interactions, participating in and controlling the assembly kinetics, ultimately leading to the formation of well-defined nanoparticles (NPs). The multicomponent peptides-based assemblies could effectively encapsulate the hydrophobic functional agent quercetin (Que), presenting good biocompatibility, antioxidant activity, and preventing DSS-induced colitis. This study elucidated the self-assembly mechanism of multicomponent peptides and demonstrated their synergistic effects with hydrophobic compounds for disease prevention, offering valuable insights into the development of novel functional materials to regulate human health.

Potential of a CO2-Responsive supramolecular drug-carrier system as a safer and more effective treatment for cancer

We combined carbon dioxide (CO2)-responsive cytosine-containing rhodamine 6G (Cy-R6G) as a hydrophobic anticancer agent with hydrogen-bonded cytosine-functionalized polyethylene glycol (Cy-PEG) as a hydrophilic supramolecular carrier to construct a CO2-responsive drug delivery system, with the aim of enhancing the responsiveness of the system to the tumor microenvironment and thus the overall effectiveness of anticancer therapy. Due to self-complementary hydrogen bonding interactions between cytosine units, Cy-R6G and Cy-PEG co-assemble in water to form spherical-like nanogels, with Cy-R6G effectively encapsulated within the nanogels. The nanogels exhibit several distinctive physical features, such as widely tunable nanogel size and drug loading capacity for Cy-R6G, intriguing fluorescence properties, high co-assembled structural stability in normal aqueous environments, enhanced anti-hemolytic characteristics, sensitive dual CO2/pH-responsive behavior, and precise and easily controllable CO2-induced release of Cy-R6G. Cytotoxicity assays clearly indicated that, due to the presence of cytosine receptors on the surface of cancer cells, Cy-R6G-loaded nanogels exert selective cytotoxicity against cancer cells in pristine culture medium, but do not affect the viability of normal cells. Surprisingly, in CO2-rich culture medium, Cy-R6G-loaded nanogels exhibit a further significant enhancement in cytotoxicity against cancer cells, and remain non-cytotoxic to normal cells. More importantly, a series of in vitro experiments demonstrated that compared to pristine culture medium, CO2-rich culture medium promotes more rapid selective internalization of Cy-R6G-loaded nanogels into cancer cells through cytosine-mediated macropinocytosis and thus accelerates the induction of apoptosis. Therefore, this newly developed system provides novel avenues for the development of highly effective CO2-responsive drug delivery systems with potent anticancer capabilities.

Substantiation of the Effectiveness of Water-Soluble Hydrophobic Agents on the Properties of Cement Composites

Substantiation of the Effectiveness of Water-Soluble Hydrophobic Agents on the Properties of Cement Composites

Study of hydrophobic cemented paste backfill (H-CPB) to prevent sulphate attack

One of the challenges encountered in mining is acid mine drainage (AMD) in sulphurous ores in response to rainfall and groundwater. CPB one of the most prevalent waste management systems addresses this issue today. Nevertheless, in the long term, the concretion in CPB may become ineffective because of external factors, such as groundwater and rainfall. The relevant sources in the literature have no mention of AMD problems that may occur in the long term with CPB, particularly in metallic ores. Most studies indicate that the issue which can be prevented by using cement. However, due to the destructive effects of nature, cement alone would be insufficient. Consequently, the research's principal aim is to form CPB hydrophobic, thereby reducing the interaction between CPB and water. In the study, stearic acid was chosen as the hydrophobic agent and application method to the CPB and the changes in load-bearing capacity were studied. Specimens were tested by ion chromatography, X-ray diffraction (XRD), elemental analysis by combustion, water absorption, uniaxial compressive strength (UCS), and scanning electron microscopy (SEM). There was a decrease in the load-bearing capacity while gaining the hydrophobic properties of the material. The results confirm the validity of the selected agent and method and reveal that the effect of sulphate decreases with increasing hydrophobicity yet, there is no significant decrease in the 7, 14, and 28-day UCS tests. The optimal results were achieved when Stearic Acid (SA) was used at a concentration of 1.25 % for 7 % Portland cement and 0.75 % for 11 % Portland cement, with a UCS strength of 1.223 and 2.008 MPa, respectively. The expected benefit of stearic acid was realized as the water absorption value of the reference sample was 2.50 times higher in 7 % cement and 4.25 times higher in 11 % cement than the same value in Hydrophobic Cemented Paste Backfill (H-CPB). These results indicate that AMD formation can be prevented in the future with H-CPB. The results demonstrate that stearic acid, with the new methodology, forms the CPB hydrophobic, while only an acceptable strength loss was observed. Additionally, the outcomes point out that the methodology adopted does not consider a significantly adverse impact on hydration phase of concretation and can be utilized as an environmentally friendly backfilling method, thereby being evaluated as the cleaner backfilling for further CPB applications.

Physiological characteristics of microbial transformation during chronic exposure to triclosan as a hydrophobic antibacterial agent and post-antibacterial cessation

ABSTRACT The use of triclosan (TCS) in hygiene products and other materials raises concerns about increased antimicrobial resistance. Research has shown that bacteria can develop resistance to TCS, but there is limited understanding of how bacterial behavior changes after TCS is removed. This study focuses on how bacteria adapt to prolonged TCS exposure and recover after its removal. It aims to improve practices for using antimicrobial agents in sanitation products and emphasize the importance of understanding exposure and recovery times to prevent resistance development. The study evaluated the bacterial behavior, determining the minimum inhibition concentration of TCS that 90% of Escherichia coli was inhibited (MIC90), predicting bacterial growth kinetics using the Modified Gompertz model and membrane permeability recovery. Bacteria showed a significant increase in resistance levels during exposure, with the MIC90 steadily increasing over 30 days and peaking at 16 mg/L. Upon removal, there was a notable 2-fold decrease in resistance after 10 days of reculturing in a non-chemical medium, likely due to restructuring changes in cell membranes. Therefore, in addition to reducing the occurrence of antibacterial agents in the environment, advanced treatments for eliminating antibacterial resistance should be performed on wastewater before being discharged into the environment.

Applying Alkali Activator and Hydrophobic Agents in Clay-Based Mortars for Enhanced Properties

Clay-based mortars are susceptible to water intake and exhibit low mechanical strength, presenting challenges in their application within the construction sector. This research addresses these vulnerabilities by investigating the combination of alkali activators with waterproofing agents, specifically a nano-clay and an acrylic emulsion, to enhance the properties of clay mortars. Alkali-activated materials are known for their superior mechanical properties and sustainable potential, especially when derived from low-cost by-products. Recent studies have focused on alkali activation using clays and soils as precursors to improve their physical and mechanical properties while increasing durability. However, the high absorbency of these mortars remains a concern, as it can lead to matrix degradation. Therefore, to address these problems, this research studied the combination of a highly alkaline activator (potassium metasilicate) with hydrophobic agents, such as a nano-clay and an acrylic emulsion, using two different clayey soils. The results indicated that potassium metasilicate (PO) enhanced the mechanical properties and stability for both aluminosilicate systems, while nano-clay (PONC) significantly reduced the capillary absorption through time, especially in A2 systems. The addition of acrylic emulsion (POD) proved highly effective in both systems, significantly improving durability. By integrating these agents, the mortar systems were protected against water intake, while durable construction materials were formed.

Robust photothermal anti/de-icing hydrophobic coating based on polydopamine (PDA) composition

The hydrophobic soft coating has low ice adhesion strength and hydrophobic stability in low-temperature and high-humidity environments, which is crucial for preventing ice formation on infrastructure and transportation systems. However, creating mechanically durable hydrophobic soft coatings using simple methods remains challenging. In this study, a high-hardness particle-toughened, self-stratifying organic layer with high photothermal conversion rate was developed to enhance coating durability and ice-repellent performance. By optimizing the ratio of dopamine (DA) and sodium alginate (SA), a hydrophobic photothermal agent (DPSn) with high hardness and a significant light-heat effect was synthesized. A durable, hydrophobic photothermal anti-ice coating (AR/20 %PDMS/x%DPS1) with varying DPS1 amounts was successfully created using a straightforward one-step spray method, utilizing the self-stratification characteristics of acrylic resin (AR) and polydimethylsiloxane (PDMS), along with the toughening effect of DPSn. The fiber cross-linked structure of DPS1 achieved a photothermal conversion rate of 87.5 %. Adding 4 wt% DPS1 increased the surface temperature of the AR/20 %PDMS coating to 96.5 ± 2.4 °C and boosted the coating’s adhesion strength from 6.70 ± 0.3 MPa to 7.23 ± 0.7 MPa. The AR/20 %PDMS/4%DPS1 coating demonstrated excellent anti-/de-icing performance after 60 friction cycles, 60 icing/de-icing cycles, and 132 h of acid-base immersion. Its simple preparation process and durable ice-repellent properties make it highly suitable for practical applications in photothermal hydrophobic soft coatings.

Impregnate Carbonation: CO2-Guided In Situ Growth of Robust Superhydrophobic Structures on Concrete Surfaces.

Superhydrophobic surfaces applying on concrete can greatly improve the durability of concrete by preventing the damage from water. However, traditional design of superhydrophobic concrete surfaces by external coating encounters to problems of flaking and poor surface robustness, while that by adding hydrophobic agents or particles faces the challenges of strength damage of concrete. Drawing inspiration from the carbonation phenomenon of concrete, here a new design of in situ growing superhydrophobic structures on concrete is proposed: The concrete sample is impregnated into Mg2+-containing silane-water system with continuous CO2 injection. The contact angle of the concrete surface achieves 171.9° without obvious strength decrease after 120 min, which are mainly attributed to the formation of CaxMg1-xCO3 crystals with micro-nano-structures and the reduction of carbonates surface energy by silane. This superhydrophobic concrete structure can be divided into a superhydrophobic-hydrophobic-hydrophilic three layers structure, providing the stable water-proof protection under mechanical fatigue, capillary water absorption, UV aging, sulfate attack, and impurity water impact tests due to the in situ growing robust superhydrophobic structures. Furthermore, it captures 29.80gm-2 CO2 during the reaction process, providing new insights for the design and preparation of eco-friendly superhydrophobic concrete.

Hydrophobic cement: Concept, preparation and application

Integral hydrophobic cement-based materials (CBMs) have traditionally been built by adding hydrophobic liquid solvents, hydrophobic solid powders, or admixtures modified by hydrophobic agents. In this work, we propose a new strategy to construct an integral hydrophobic CBMs based on direct hydrophobic cement. By ball milling, the 1.0 wt% stearic acid (SA) is adopted as modifier to prepare hydrophobic cement (SA1.0). SA1.0 process provides better dispersity in making CBMs. Hence, by using SA1.0 process, the CMB mechanical properties and durability can be improved. The mechanical and working performance of SA1.0 meet P·O 42.5 grade. Freeze-thaw resistance, sulfate resistance and electrochemical tests have demonstrated that CBMs prepared via SA1.0 process own excellent durability. Our findings provide new strategies for the formation of integral hydrophobic CBMs and a novel hydrophobic cementitious material for long-life CBMs.

On-Demand Removable Chitosan Based Self-Healing and Antibacterial Hydrogel for Delivery of Tetracycline and Curcumin As Potential Wound Dressing Material.

Wound care is a flourishing branch of healthcare wherein a great amount of research is devoted to develop competent wound dressings. Safe, cost-effective, and biocompatible dressings aid in wound healing without inflicting external trauma and subsequent scar formation. Toward this, we have attempted to develop robust wound dressing material with self-healing and antibacterial properties. We have cross-linked chitosan with 4-formyl phenylboronic acid (4-FPBA) and in situ generated dehydroascorbic acid (DHA) utilizing the dynamic imine and boronate ester linkages. Displaying a channeled microstructure in the SEM micrographs, the hydrogel exhibits a massive water uptake capacity of ∼900% at acidic pH. The hydrogel could completely self-heal within 3 min, and the results are further supported by rheological analysis. By virtue of positive surface charge, it shows a promising tissue adhesive property. Moreover, it affords clean and compliant removal from the wound surface via dissolution induced by dopamine to potentially reduce secondary scarring from peeling of wound dressings. The dressing could significantly act against skin infections caused by S. aureus bacteria with enhanced antimicrobial efficiency via loading of antibiotic drug, tetracycline hydrochloride. A sustained release of tetracycline and Curcumin was observed, which demonstrated the release ability for hydrophilic and hydrophobic bioactive agents. In-vitro studies revealed 93% cell viability with a hemolytic ratio as low as 2.5%, thereby presenting a good self-healing and biocompatible material for wound healing.

Assessment of Surface Treatment Systems for Protecting Concrete Structure

The BS EN 1504-2:2004 groups surface treatments into three types: impregnations, hydrophobic impregnations, and surface applied corrosion inhibitors. Impregnations reduce surface porosity by filling concrete pores, while hydrophobic impregnations create a water-repellent surface without filling pores. Surface applied corrosion inhibitors form a protective film on the rebar surface. Impregnation strengthens the surface by blocking pores with reaction products that reduce ingress of aggressive agents. Hydrophobic impregnation produces a hydrophobic and water-repellent surface that inhibits water penetration while allowing concrete to breathe. Corrosion inhibitors migrate to the steel surface and form a mono-molecular film, preventing further corrosion. In this study accelerated corrosion test was used for determination of the effectiveness of each category in offering corrosion protection by subjecting concrete specimens coated with these surface treatments to accelerated corrosion conditions that is intended to induce corrosion in the embedded rebars. This paper presents test results for the performance of these three surface treatments on grade G30 and G40 concretes. Results show that hydrophobic agents are more effective than traditional impregnates in reducing water absorption and chloride penetration.

Corrosion and tribocorrosion resistance of superhydrophobic LPBF-NiTi alloys surface fabricated by nanosecond laser and ultrasonic fluorination

NiTi alloys have been extensively studied for their excellent super-elasticity (SE) and shape memory effects (SME). With the development of laser powder bed fusion (LPBF), it is possible to process the complex structure of NiTi alloy, which results in the mechanical properties of LPBF-NiTi alloys receiving great attention. However, the processing method is different from the traditional one, which not only has an impact on the mechanical properties but also seriously affects the anti-corrosion resistance and causes a substantial deterioration. In the research work of this paper, nanosecond laser processing was used to fabricate the bionic mastoid-shaped micro-nano structure on the LPBF-NiTi alloys. An efficient and convenient ultrasonic fluorination treatment was used to achieve the full surface coverage of FAS-17 in 10 min, and the superhydrophobic LPBF-NiTi alloy surface (CA ~ 157°) was successfully achieved. The constructed superhydrophobic LPBF-NiTi alloy surface exhibits excellent anti-corrosion resistance compared with the original surface, and the icorr from (4.42 ± 0.5) × 10−7 A·cm−2 reduced to (3.21 ± 0.5) × 10−9 A·cm−2. Meanwhile, the superhydrophobic surface showed outstanding stability in the 15-day immersion test n 3.5 wt% NaCl solution. And it is also stable after the tribocorrosion tests in 3.5 wt% NaCl solution at 1 N and 5 N pressures. The remarkable anti-corrosion resistance and stability of the superhydrophobic surface can be attributed to the micro-nano structure rich in the TiO2 oxide layer, the air layer formed by the superhydrophobic surface insulates the corrosive liquid and the stable hydrophobic agent film.

Betulin Enables Multifunctional Cellulose-Based Insulative Foams with Low Environmental Impacts.

The significance of synthetic foams as insulative materials stems from their mechanical and water resistance as well as their cost-effectiveness. Broadly, the design of building envelopes should also consider fire and mold resistance and the impacts on the environment (end of life and compostability). This study addresses these issues considering the ever-increasing demand for sustainable sources to develop highly porous insulative materials. We introduce a versatile strategy based on wet-foam laying of cellulosic fibers that leads to hierarchical structures whose performance is tailored by the surface incorporation of betulin (BT), a bioactive molecule extracted from tree bark, combined with poly(dimethylsiloxane) (PDMS) after installation of urethane linkages. As such, we introduce an eco-friendly alternative to traditional polyurethane foams with competitive mechanical and thermal insulation performance. The modification of the fiber foams at low BT loading simultaneously endows superhydrophobicity (water contact angle >150°), fire retardancy (self-extinguish within 10 s), microbial resistance, and durability (no degradation in soil conditions after 3 months). BT plays a critical role as an antimicrobial and hydrophobic agent that synergizes with PDMS to achieve fire resistance. The life cycle assessment of the BT-modified foams reveals a significant reduction in greenhouse gas emission and human toxicity compared with rigid polyurethane foams by 96 and 92%, respectively. Overall, the valorization of the bark-derived BT is demonstrated by considering the scalability and cost-effectiveness of solid foams designed to substitute petroleum-derived counterparts.

Evaluation of nanoparticle-enhanced silane and vinyl ester coatings for protecting concrete from ammonium sulfate

Inferior quality of concrete surface layers can lead to significant deterioration of concrete infrastructure due to the infiltration of fluids and deleterious substances from the surrounding environment. Concrete structures such as foundations, abutments, flatwork, and underground tanks in agricultural and mining zones, as well as slabs in factories producing ammonium-based fertilizers, are highly susceptible to ammonium sulfate attack, which is known as the most aggressive sulfate deterioration driven by acid-sulfate reactions. Coatings are an effective strategy for protecting such concrete structures to restore its performance and prolong its service life. Therefore, this study aimed at investigating the performance of nano-based coatings as superficial treatments for concrete elements exposed to aggravated exposures of ammonium sulfate. Silane (hydrophobic agent) and vinyl ester (membrane-forming polymer) were used as base resins, in which nano-clay and nano-calcium carbonate particulates were dispersed at different dosages (0, 2.5, and 5 %). In addition, a colloidal silica solution was used as a surface treatment. The durability of coated concrete specimens was evaluated under two ammonium sulfate exposures: full immersion and combined with cyclic environmental conditions (freezing-thawing and wetting-drying cycles). Degradation of concrete specimens was monitored by visual assessment and quantified in terms of mass and length changes over time. In addition, the deterioration mechanisms and coatings’ performance were studied by thermal, mineralogical, and microstructural tests. The results showed that colloidal silica could not adequately protect concrete specimens from these exposures. Conversely, silane nanocomposites improved the durability of concrete under both exposures and superior performance was generally observed for concrete specimens coated with vinyl ester nanocomposites.

Impact and migration behavior of triclosan on waste-activated sludge anaerobic digestion

Triclosan (TCS), a hydrophobic antibacterial agent, is extensive application in daily life. Despite a low biodegradability rate, its hydrophobicity results in its accumulation in waste-activated sludge (WAS) during domestic and industrial wastewater treatment. While anaerobic digestion is the foremost strategy for WAS treatment, limited research has explored the interphase migration behavior and impacts of TCS on WAS degradation during anaerobic digestion. This study revealed TCS migration between solid- and liquid-phase in WAS digestion. The solid–liquid distribution coefficients of TCS were negative for proteins and polysaccharides and positive for ammonium. High TCS levels promoted volatile-fatty-acid accumulation and reduced methane production. Enzyme activity tests and functional prediction indicated that TCS increased enzyme activity associated with acid production, in contrast to the inhibition of key methanogenic enzymes. The findings of the TCS migration behavior and its impacts on WAS anaerobic digestion provide an in-depth understanding of the evolution of enhanced TCS-removing technology.

Performance Evaluation of Thermal Insulation Materials from Sheep's Wool and Hemp Fibres.

In the current work, the performance properties of natural-fibre-based thermal insulation materials were examined. For this purpose, three different compositions of natural fibres were prepared: pure sheep wool (SW), wool and industrial hemp (SW/HF) fibres, and pure industrial hemp (HF) fibres. Low-melt bicomponent polylactide (PLA) fibres were used as a binding material. For specimens prepared from natural fibres, the dependence of the thermal conductivity, the tensile strength along and across the direction of product formation, and the short-term water absorption on the density of the specimens and the flammability parameters were determined. In addition, to reduce the water absorption and flammability, the specimens were coated with hydrophobic agents and flame retardants. The obtained research results were also statistically processed. The analysis of the results showed that the thermal conductivity of natural-fibre-based thermal insulation materials varied within the range of 0.0333 ÷ 0.0438 W/(m·K), the tensile strength varied from 2.5 to 130 kPa, the short-term water absorption varied from 0.5 to 8.5 kg/m2, and the water vapour diffusion resistance factor varied from 2.537 to 2.667. It was additionally determined that all the studied products were flammable. The water absorption and flammability values were significantly reduced by the use of hydrophobic agents and flame retardants.

Unveiling the Role of PTFE Surface Coverage on Controlling Gas Diffusion Layer Water Content.

Gas diffusion layers (GDLs) are usually coated with a hydrophobic agent to achieve a delicate balance between liquid and gas phases to maximize mass transport. Yet, most GDL numerical models to date have assumed an average contact angle for all materials, thereby eliminating the possibility of studying the role of the polytetrafluoroethylene (PTFE) content. This study introduces two mixed wettability algorithms to predict the mixed wetting behavior of GDLs composed of multiple materials. The algorithms employ contact angle and distance to solid materials to determine the critical capillary pressure for each pore voxel. The application of the algorithms to the estimation of capillary pressure vs saturation curves for two GDLs, namely, a micro-computed tomography (μ-CT) reconstructed SGL 39BA GDL and a stochastically reconstructed Toray 120C GDL, showed that, in agreement with experimental data, the addition of PTFE resulted in a decrease in saturation at a given capillary pressure. For Toray-120C, the mixed wettability model was capable of reproducing experimentally observed features in the intrusion curve at low saturation that could not be reproduced with a single wettability model, providing a clear link between PTFE coverage and intrusion at low saturation. Numerical results also predicted an increased breakthrough pressure and a decrease in saturation with increasing PTFE, in agreement with experimental observations. The decreased saturation at breakthrough improves gas transport through the layer while maintaining the layer's ability to remove water. Diffusivity simulations confirm the increase in diffusivity at breakthrough with increasing PTFE, thereby providing a rationale for the addition of PTFE, as well as for the optimal amount. This study emphasizes the importance of multimaterial wetting models and calls for more detailed investigations into PTFE and ionomer distributions in GDLs and catalyst layers, respectively.