Adhesive Polydopamine Research Articles

Double bioinspired of robust BaSO4/SnO2 membrane with anti-crude oil adhesion and remarkable emulsion separation

Pollution from oily waste water is a serious environmental problem worldwide, causing serious damage to the environment and human health. At the same time, emulsifiers also cause great difficulties in wastewater treatment. Although efforts have been made to develop many high performance emulsion separation membranes, it is difficult to have the ability to resist crude oil pollution in practical applications. The construction of superoleophobic micro/nano-scale lamellar structured membranes with the potential to efficiently separate oil/water emulsions was inspired by the observation of bi-organisms, specifically the oil-resistant properties of fish scales and the unique adhesion of mussels. Tin dioxide, polydopamine and hydrophilic barium sulphate have been modified on the surface of stainless steel mesh by in-situ hydrothermal and dip coating. The superhydrophilic stainless steel mesh was successfully prepared by using the adhesion of polydopamine. Using the excellent underwater hydration ability of tin dioxide and the hydroxyl group-rich hydrophilic barium sulfate, the modified membrane showed excellent resistance to crude oil pollution. The superhydrophilic membrane can continuously separate different types of oil-in-water emulsions with high separation efficiency (99.9 %) and excellent separation flux (900 L m−2 h−1), with no decrease in efficiency and flux after 10 emulsion separation cycles. In addition, the superhydrophilic membrane has excellent durability and stability, remaining super-oleophobic underwater to sand shock, sandpaper abrasion, high saline corrosion and UV ageing. The prepared stainless steel membrane not only provides a novel anti-fouling strategy, but its excellent stability also provides some new inspiration for the treatment of oil and water pollution in the future.

Polydopamine modification on dendritic porous silica surface for efficient adhesion of functional nanoparticles

The uniform and high-density immobilization of functional nanoparticles (NPs) on porous carriers is crucial to enhance various physicochemical properties and performances in diverse applications. However, there is a limited control towards the size and distribution of functional nanoparticles loaded on the carriers. In this work, the dendritic porous silica nanoparticles (DPSNs) featuring a three-dimensional center-radial porous structure were utilized as a nanocarrier, coated with a thin layer of polydopamine (PDA) to form DPSNs@PDA. The modified PDA exhibits strong adhesion and photothermal conversion properties. The pre-synthesized gold or platinum NPs (Au or Pt NPs) with tunable sizes were uniformly and densely loaded on the DPSNs@PDA, taking advantage of the strong adhesion properties of PDA. The resulting functional NPs-loaded DPSNs@PDA composites demonstrated excellent catalytic activity and recycling stability in heterogeneous catalysis, achieving over 95 % catalytic conversion efficiency of methylene blue (MB) after six cycles. Furthermore, due to the excellent photothermal effects of PDA and Au NPs, the apparent reaction rate increased by nearly threefold under 808 nm near-infrared (NIR) laser irradiation. The developed strategy of loading pre-synthesized NPs with tunable sizes by strong PDA adhesion force shows great potential for achieving efficient integration of various functional NPs, thereby facilitating the construction of advanced multifunctional materials.

Bacteria‐Mediated Bismuth‐Based Nanoparticles Activate Toll‐Like Receptors for Breast Cancer Photothermal Immunotherapy

AbstractOne of the latest immunotherapeutic strategies involves modulating the tumor microenvironment through Toll‐like receptors (TLRs). However, Toll‐like receptor agonists may induce severe systemic inflammation. Bif@PBi‐R, a bacterial nanomotor is developed with tumor‐targeting properties in this study. Bismuth‐based nanoparticles loaded with R848 (Bi‐R NPs) are bound to anaerobic bifidobacteria via polydopamine adhesion. Bif@PBi‐R is designed to deliver bismuth‐based nanoparticles carrying R848 specifically to the tumor area to activate anti‐tumor immunotherapy. Bismuth is an excellent nanomaterial for photothermal conversion. Therefore, Bif@PBi‐R not only enhances the efficacy of photothermal therapy to kill tumor cells directly but also boosts the anti‐tumor immune response through its photothermal therapeutic effect. Combining Bif@PBi‐R with 808 nm laser irradiation significantly promoted dendritic cell (DCs) maturation, leading to a potent anti‐tumor effect. In summary, this bacterial nanomotor effectively enhances the efficacy of immunotherapy when combined with photothermal therapy (PTT).

Stimuli-Responsive Ion Transport Regulation in Nanochannels by Adhesion-Induced Functionalization of Macroscopic Outer Surface.

Responsive regulation of ion transport through nanochannels is crucial in the design of smart nanofluidic devices for sequencing, sensing, and water-energy nexus. Functionalization of the inner wall of the nanochannel enhances interaction with ions and fluid but restricts versatile chemical approaches and accurate characterizations of fluidic interfaces. Herein, we reveal a responsive regulating mechanism of ion transport through nanochannels by polydopamine (PDA)-induced functionalization on the macroscopic outer surface of nanochannels. Responsive molecules were codeposited with PDA on the outer surface of nanochannels and formed a valve of nanometer thickness to manually manipulate ion transport by changing its gap spacing, surface charge, and wettability under external stimulus. The response ratio can be up to 100-fold by maximizing the proportion of responsive molecules on the outer surface. Laminating the codepositions of different responsive molecules with PDA on the channel's outer surface produces multiple responses. A nearly universal adhesion of PDA with responsive molecules on the open outer surface induces nanochannels responsive to different external stimuli with variable response ratios and arbitrary combinations. The results challenge the primary role of functionalization on the nanoconfined interface of nanofluidics and open opportunities for developing new-style nanofluidic devices through the functionalization of macroscopic interface.

MXene-based thermoelectric fabric integrated with temperature and strain sensing for health monitoring

Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electronics, offering applications in energy harvesting, movement tracking, and health monitoring. Nevertheless, developing thermoelectric devices with exceptional flexibility, enduring thermoelectric stability, multifunctional sensing, and comfortable wear remains a challenge. In this work, a stretchable MXene-based thermoelectric fabric is designed to accurately discern temperature and strain stimuli. This is achieved by constructing an adhesive polydopamine (PDA) layer on the nylon fabric surface, which facilitates the subsequent MXene attachment through hydrogen bonding. This fusion results in MXene-based thermoelectric fabric that excels in both temperature sensing and strain sensing. The resultant MXene-based thermoelectric fabric exhibits outstanding temperature detection capability and cyclic stability, while also delivering excellent sensitivity, rapid responsiveness (60 ms), and remarkable durability in strain sensing (3200 cycles). Moreover, when affixed to a mask, this MXene-based thermoelectric fabric utilizes the temperature difference between the body and the environment to harness body heat, converting it into electrical energy and accurately discerning the body's respiratory rate. In addition, the MXene-based thermoelectric fabric can monitor the state of the body's joint through its own deformation. Furthermore, it possesses the capability to convert solar energy into heat. These findings indicate that MXene-based thermoelectric fabric holds great promise for applications in power generation, motion tracking, and health monitoring.

Polydopamine Adhesion: Catechol, Amine, Dihydroxyindole, and Aggregation Dynamics.

While polydopamine (PDA) possesses the surface-independent adhesion property of mussel-binding proteins, significant differences exist between them. Particularly, PDA's short and rigid backbone differs from the long and flexible protein sequence of mussel-binding proteins. Given that adhesion relies on achieving a conformal contact with large surface coverage, PDA has drawbacks as an adhesive. In our study, we investigated the roles of each building block of PDA to build a better understanding of their binding mechanisms. Initially, we anticipated that catecholamine oligomers form specific binding with substrates. However, our study showed that the universal adhesion of PDA is initiated by the solubility limit of growing oligomers by forming agglomerates, complemented by multiple binding modes of catechol. Notably, in the absence of amines, poly(catechol) either remained in solution or formed minor suspensions without any surface coating, underscoring the essential role of amines in the adhesion process by facilitating insoluble aggregate formation. To substantiate our findings, we induced poly(catechol) aggregation using quaternized poly(4-vinylpyridine) (qPVP), leading to subsequent surface adhesion upon agglomerate formation.

Underoil superhydrophilic flame-retardant 3D porous composite for efficient on-demand emulsion separation: Interface engineering design on sphagnum moss

Oil pollution and the energy crisis make oil-water separation an urgent for human need. The widespread use of materials with a single emulsion separation capability is limited. Multifunctional on-demand separation materials can adapt to a wide range of application scenarios, thus having a wider range of applications. The underoil superhydrophilic surface is of great significance for realizing the on-demand separation of oil/water emulsions through the removal of water in the oil and oil in the water. A 3D porous emulsion separation material based on the superhydrophilic principle of sphagnum moss was designed. The material was prepared in a simple step by taking advantage of the adhesion of polydopamine and the introduction of the as-prepared superhydrophilic BaSO4 nanoparticles to achieve superhydrophilicity with a water contact angle (WCA) of 0° and an oil contact angle (OCA) of 157.3°, resulting in excellent separation performance for both water-in-oil and oil-in-water emulsions. Underoil superhydrophilic porous composite (OSPC) can complete two kinds of emulsion separations by filtration or adsorption. It adsorbs water from water-in-oil emulsion to achieve separation, with a good adsorption capacity of 74.38 g/g and efficiency up to 99%. It can also filter oil-in-water emulsions with an efficiency of 99.92%. The separation efficiencies are all almost unchanged after ten separation cycles. Furthermore, the material has excellent flame retardancy, which reduces the possibility of secondary disasters. The three-dimensional porous sponge has excellent on-demand separation performance for multiple emulsions. It provides a new preparation strategy for underoil superhydrophilic materials and a new idea for the design direction of special wetting materials for the on-demand separation of oil/water emulsions.

Polydopamine Enhanced Interactions of Graphene Nanosheets to Fabricate Graphene/Polydopamine Aerogels with Effectively Clear Organic Pollutants.

Graphene/polydopamine aerogels (GPDXAG, where X represents the weight ratio of DA·HCl to GO) were prepared by the chemical reduction of graphene oxide (GO) using dopamine (DA) and l-ascorbic acid as reducing agents. During the gelation process, DA was polymerized to form polydopamine (PDA). The introduction of PDA in the gelation of aerogels led to a deeper reduction of GO and stronger interactions between graphene nanosheets forced by covalent cross-linking and noncovalent bonding including π-π stacking and hydrogen bonding. The weight ratio of DA·HCl to GO influencing the formation and morphology of GPDXAG was explored. With the increasing content of DA in gelation, the reduction of GO and the cross-linking degree of graphene nanosheets were enhanced, and the resulting GPDXAG had a more regular pore distribution. Additionally, introducing PDA into GPDXAG improved its hydrophobicity because of the adhesion of PDA to a network of aerogels. GPDXAG exhibited a higher removal efficiency for organic pollutants than the controlled graphene aerogels (GAG). Specifically, the adsorption capacity of GPDXAG for organic solvents was superior to that of GAG, and organic solvent was completely separated from the oil/water mixture by GPDXAG. The equilibrium adsorption capacity of GPDXAG for malachite green (MG) was measured to be 768.50 mg/g, which was higher than that for methyl orange (MO). In MG/MO mixed solutions, aerogels had obvious adsorption selectivity for the cationic dye. The adsorption mechanism of aerogels for MG was also discussed by simulating adsorption kinetic models and adsorption isothermal models.

Improving the interfacial adhesion between recycled carbon fibres and polyphenylene sulphide by bio-inspired dopamine for advanced composites manufacturing

Polyphenylene sulphide composites with recycled carbon fibres are of high interest due to their promising mechanical properties. Poor interface adhesion between recycled carbon fibre and thermoplastic matrix, however, remains a major problem in composite manufacturing. Herein, a novel one-step method using bio-inspired copolymerisation of dopamine to graft silica nanoparticles onto the carbon fibre surface is reported. Comprehensive investigations were conducted to fabricate the treated carbon fibre and characterise the modified samples by analysing the surface morphology and functional groups. The experimental results reveal that the network of bio-inspired adhesive polydopamine and nanoparticles adhering to the fibres can improve inter-laminar shear strength by 28.4% in the resulting composites. In addition, dynamical mechanical analysis results prove that the interfacial bonding at the fibre/matrix interface provides good resistance to thermal cycling. This novel approach introduces the functional groups on the recycled carbon fibre surface, leading to an improvement of surface energy and wettability between the carbon fibres and polyphenylene sulphide matrix and constitutes a robust and green approach to the manufacturing of advanced composites.

Mussel-inspired polydopamine-modified biochar microsphere for reinforcing polylactic acid composite films: Emphasizing the achievement of excellent thermal and mechanical properties

Having poor interfacial compatibility between biochar microsphere (BM) and polylactic acid (PLA) should be responsible for the unbalance of composite film strength and toughness. Elucidating the effect of polydopamine (PDA) on BM and BM/PLA composite films is the ultimate goal of this study based on the mussel bionic principle. It was found that the strong adhesion of PDA on the BM surface was achieved, which improved the surface roughness and thermal stability. Also, PDA modification can facilitate crystallization, increase thermal properties, improve interfacial compatibility, and enhance the tensile properties of BM/PLA composite films. Silane-based PDA modified BM/PLA composite film exhibited the best tensile strength, tensile modulus, and elongation at break with 77.95 MPa, 1.87 GPa, and 7.30%. These noteworthy findings, achieving a simultaneous improvement in PLA strength and toughness, hold promising implications for its sustainability.

Temperature and photosensitive PVDF-g-PNIPAAm/GPE-PDA@ZnO composite membranes with efficient dyes separation capability and light-cleaning function

In this paper, PVDF-g-PNIPAAm/GEP-PDA@ZnO composite membranes that can undergo light-induced structural response and photodegradation to achieve self-cleaning have been designed and applied to the separation and purification of dye wastewater. The membranes were prepared by blending graphene (GPE)-polydopamine (PDA)-coated zinc oxide (ZnO) core–shell particles into the PVDF-g-PNIPAAm matrix with a non-solvent induced phase separation technique. The GPE and ZnO are tightly bonded by highly adhesive PDA to form a “strawberry-like” core–shell structure. GPE absorbs light energy and converts it into heat, resulting in changes in PNIPAAm chain segments to expand the pore size for self-cleaning. While the membrane is warming up, GPE further promotes the activation of active groups on the surface of PDA@ZnO at high temperature, resulting in unique and excellent photothermal catalytic activity. As a result, the membrane achieves both self-cleaning and pollutant degradation, which results in an FRR of 99.6% after light cleaning. Moreover, the GPE-PDA@ZnO nanoparticle-modified PVDF-g-PNIPAAm membranes exhibit excellent cycling stability with a degradation flux recovery rate of more than 97% even after multiple UV cleaning. Thus, PVDF-g-PNIPAAm/GPE-PDA@ZnO composite membranes extend the versatility of PVDF-based membranes and show extraordinary potential for application in wastewater treatment.

Mussel-inspired electroactive, antibacterial and antioxidative composite membranes with incorporation of gold nanoparticles and antibacterial peptides for enhancing skin wound healing

Large skin wounds are one of the most important health problems in the world. Skin wound repair and tissue regeneration are complex processes involving many physiological signals, and effective wound healing remains an enormous clinical challenge. Therefore, there is an urgent need for a strategy to rapidly kill bacteria, promote cell proliferation and accelerate wound healing. At present, electrical stimulation (ES) is often used in the clinical treatment of skin wounds and can simulate the endogenous biological current of the body and accelerate the repair process of skin wounds. However, a single ES strategy has difficulty covering the entire wound area, which may lead to unsatisfactory therapeutic effects. To overcome this deficiency, it is essential to develop a collaborative treatment strategy that combines ES with other treatments. In this study, gold nanoparticles and antibacterial peptides (Os) were loaded on the surface of poly(lactic-co-glycolic acid) (PLGA) material through the reducibility and adhesion of polydopamine (PDA) and improved the electrical activity, anti-inflammatory, antibacterial and biocompatibility properties of the polymer material. At the same time, this composite membrane material (Os/Au-PDA@PLGA) combined with ES was used in wound therapy to improve the wound healing rate. The results show that the new wound repair material has good biocompatibility and can effectively promote cell proliferation and migration. Through the combined application of gold nanoparticles and antibacterial peptides Os, the polymer materials have more efficient bactericidal and antioxidant effects. The antibacterial experiment results showed that gold nanoparticles could further enhance the antibacterial activity of antibacterial peptides. Furthermore, the Os/Au-PDA@PLGA composite membrane has good hydrophilicity and electrical activity, which can provide a more favorable cell microenvironment for wound healing. In vivo studies using a full-thickness skin defect model in rats showed that the Os/Au-PDA@PLGA composite membrane had a better therapeutic effect than the pure PLGA material. More importantly, the combination of the Os/Au-PDA@PLGA composite with ES significantly accelerated the rate of vascularization and collagen deposition and promoted wound healing compared with non-ES controls. Therefore, the combination of the Au/Os-PDA@PLGA composite membrane with ES may provide a new strategy for the effective treatment of skin wounds.

Structural comparison between polydopamine precipitate and thin coating layers, down to nanometer film thicknesses

Despite the large number of investigations and applications of polydopamine (PDA), an atomic-scale description of the differences between PDA as a coating layer and PDA precipitate (bulk-PDA) based on clear experimental evidence is not reported yet. In this paper, a two-step approach was used to solve this shortcoming: (i) the deuteration of the dopamine’s catechol-ring to obtain deuterated PDA-based structures, i.e., bulk-PDA and PDA coating layers with different thickness deposited onto SiO2 nanospheres, and (ii) application of different solid-state NMR methods (13C/15N cross-polarization and 2H solid-echo) and electronic microscopy for characterization of the prepared samples in both, deuterated and non-deuterated form. It was found that nano-sized PDA coating layers and bulk-PDA are structurally equivalent at all length scales, down to monomeric units composing the final material. Ss-NMR proved sensitive to identify the distinctive contributions of PDA film surfaces in the 13C and 15N ss-NMR spectra for film thicknesses of 5 nm and less. They consist of amplified line intensities for the aliphatic carbons and NH3+, suggesting the larger number of monomeric units carrying these moieties that exist at the film surfaces compared to the inner oligomer layers. The relevance of these findings for better explaining PDA adhesion is discussed.

Magnetic resonance imaging of pancreatic islets using tissue–adhesive particles containing iron oxide nanoparticles

Post–transplantation tracking of pancreatic islets is a prerequisite for advancing cell therapy to treat type 1 diabetes. Magnetic resonance imaging (MRI) has emerged as a safe and non–invasive technique for visualizing cells in clinical applications. In this study, we proposed a novel MRI contrast agent formulation by encapsulating iron oxide nanoparticles (IONPs) in poly(lactic–co–glycolic acid) (PLGA) particles functionalized with a tissue adhesive polydopamine (PD) layer (IONP–PLGA–PD MS). Intriguingly, our particles facilitated efficient and robust labeling through a one–step process, allowing for the incorporation of a substantial amount of IONPs without detrimental impacts on the viability and functionality of pancreatic islets. The MRI signals emanating from islets labeled using our particles were found to be stable over 30 days in vitro and 60 days when transplanted under kidney capsules of diabetic mice. These results suggest that our approach provides a potential platform for monitoring the fate of pancreatic islets after transplantation.

In-situ growth of hexaconazole/polydopamine/hexadecyltrimethoxysilane in multi-scale structured wood to prepare superhydrophobic wooden materials with decay resistance

Using the layered channels of wood and its unique mesoporous microstructure, hexaconazole, polydopamine (PDA), and hexadecyltrimethoxysilane (HDTMS) were grown and deposited in-situ on the surface and interior of wood. Using this method, a superhydrophobic wood composite with decay resistance was prepared. Hexaconazole inhibited wood fungal decay, and the mass losses of wood were 0 and 0.06% with a retention of 140 g/m3 after laboratory decay tests for 12 weeks by using Trametes versicolor and Gloeophyllum trabeum, respectively. More importantly, through the oxidative self-polymerization of PDA, the adhesive PDA anchored hexaconazole nanoparticles to form a stable core–shell structure that increased the surface roughness of wood. In addition, based on the association of PDA with hydrophilic –OH groups in cellulose and hemicelluloses in wood, long-chain HDTMS was deposited on the surface of wood to form a superhydrophobic multifunctional wooden material with a water contact angle (WCA) of 154°. Based on its multifunctional and inherent durability, the wood also showed good chemical stability and resistance to UV, high- temperature, and high-humidity environments.

Polarity Conversion of the Ag2S/AgInS2 Heterojunction by Radical-Induced Positive Feedback Polydopamine Adhesion for Signal-Switchable Photoelectrochemical Biosensing.

Efficient tuning of the polarity of photoactive nanomaterials is of great importance in improving the performance of photoelectrochemical (PEC) sensing platforms. Herein, polarity of the Ag2S/AgInS2 heterojunction is converted by radical-induced positive feedback polydopamine (PDA) adhesion, which is further employed to develop a signal-switchable PEC biosensor. In the nanocomposites, Ag2S and AgInS2 achieve electron-hole separation, exhibiting a strong anodic PEC response. Under the irradiation of light, the Ag2S/AgInS2 heterojunction is able to produce superoxide radical and hydroxyl radical intermediate species, leading to the polymerization of dopamine (DA) and the subsequent adhesion of PDA onto the Ag2S/AgInS2 heterojunction (Ag2S/AgInS2@PDA). By constructing a new electron-transfer pathway with PDA, the polarity of the Ag2S/AgInS2 heterojunction is converted, and the PEC response changes from anodic to cathodic photocurrents. In addition, since the photoreduction activity of PDA is stronger than that of the Ag2S/AgInS2 heterojunction, more superoxide radical can be produced by Ag2S/AgInS2@PDA once PDA is generated, thereby promoting the generation of PDA. Consequently, a positive feedback mechanism is established to enhance the polarity conversion of the Ag2S/AgInS2 heterojunction and amplify the responding to DA. As a result, the bioanalytical method is capable of sensitively quantifying DA in 10 orders of magnitude with an ultralow limit of detection. Moreover, the applicability of this biosensor in real samples is identified by measuring DA in fetal bovine serum and compared with a commercial ELISA method. Overall, this work offers an alternative perspective for adjusting photogenerated carriers of nanomaterials and designing high-performance PEC biosensors.

Artificial Periosteum with Oriented Surface Nanotopography and High Tissue Adherent Property.

Massive periosteal defects often significantly impair bone regeneration and repair, which have become a major clinical challenge. Unfortunately, current engineered periosteal materials can hardly currently focus on achieving high tissue adhesion property, being suitable for cell growth, and inducing cell orientation concurrently to meet the properties of nature periosteum. Additionally, the preparation of oriented surface nanotopography often relies on professional equipment. In this study, inspired by the oriented collagen structure of nature periosteum, we present a composite artificial periosteum with a layer of oriented nanotopography surface containing carbon nanotubes (CNTs), cross-linked with adhesive polydopamine (PDA) hydrogel on both terminals. An oriented surface structure that can simulate the oriented alignment of periosteal collagen fibers can be quickly and conveniently obtained via a simple stretching of the membrane in a water bath. With the help of CNTs, our artificial periosteum exhibits sufficient mechanical strength and desired oriented nanotopological structure surface, which further induces the directional arrangement of human bone marrow mesenchymal stem cells (hBMSCs) on the membrane. These oriented hBMSCs express significantly higher levels of osteogenic genes and proteins, while the resultant composite periosteum can be stably immobilized in vivo in the rat model of massive calvarial defect through the PDA hydrogel, which finally shows promising bone regeneration ability. We anticipate that the developed functional artificial periosteum has great potential in biomedical applications for the treatment of composite defects of the bone and periosteum.

Tribological properties of differently shaped zinc‐based metal‐organic framework particles reinforced epoxy resin composites

AbstractIn this work, two zinc‐based metal–organic frameworks (Zn‐MOFs) with different morphologies were successfully produced by the surfactant‐mediated synthesis method. They were grown on the Polytetrafluoroethylene (PTFE)/polydopamine (PDA) to prepare PTFE/PDA/Zn‐MOFs fiber fabrics. Then the epoxy resin (EP) matrix was poured onto fabrics to prepare EP/PTFE/PDA/Zn‐MOF. PTFE was modified by introducing a PDA adhesion layer, which can provide absorption sites for Zn‐MOFs growth and improve the bonding strength with EP. The microscopic morphologies and structures of the PTFE and modified PTFE were studied. Compared with pure EP, the friction coefficient and specific wear rate of the EP/PTFE/PDA/ZnMOF2 composite were reduced by 67% and 91%, and the EP/PTFE/PDA/ZnMOF1 composite were reduced by 55% and 88%, respectively, which were due to the loading of ZnMOF2 onto the PTFE surface, improving the interfacial bonding between the PTFE and EP matrix and can prevent the PTFE fabric from coming out of the EP matrix. ZnMOF2 also presents its structural advantage: the unique thin layer structure plays a vital role in friction and wear reduction.

Electromagnetic interference shielding composites obtained from waste face masks, MXene and polyethylene terephthalate micro plastics

Since the COVID-19 in 2019, people have made a lot of progress in the recycling of waste face masks (FMs) pollution. Besides, conducting polymer composites (CPCs) possessing excellent electromagnetic interference shielding effectiveness (EMI SE) are effective method to prevent the harm caused by electromagnetic pollution. Finally, effective measures are needed to reduce the harm of micro plastics (MPs) pollution in water environment. However, in the current research on the removal of MPs, after being removed from water, MPs still exist as a waste and cannot be further recycled. Therefore, the pollution problem of MPs has not been fundamentally solved. Herein, FMs, polyethylene terephthalate MPs (PET MPs) and MXene were used to fabricate EMI shielding composites with isolated conductive networks structure via the adhesion of polydopamine (PDA). The effects of isolated conductive networks, different sizes of PET MPs and different layers of FMs on the adsorption properties of FMs-PDA-MXene, as well as electrical performance for the obtained PP-PDA-MXene composites were studied. The composites displayed EMI SE for 30.5 dB in X-band with 1.5 vol.% MXene content due to the isolated conductive networks structure. This study points out the direction for thoroughly solving the recycling problem of Microplastics after being removed from water.

Triple kill: Fabrication of composites coming from waste face masks, polystyrene microplastics, graphene, and their electromagnetic interference shielding behaviors

AbstractConducting polymer composites possessing excellent electromagnetic interference shielding effectiveness (EMI SE) are effective methods to prevent the harm caused by electromagnetic pollution. Since COVID‐19 in 2019, people have made a lot of progress in the recycling of waste face masks (FMs). Besides, effective measures are needed to reduce the harm of microplastics (MPs) pollution in the water environment. However, so far, no publications are available in the literature that simultaneously solve the problem of electromagnetic pollution, FM pollution, and MP pollution. Herein, FMs, polystyrene MPs (PS MPs), and graphene (Gr) were used to fabricate EMI shielding composites with isolated conductive network structures via the adhesion of polydopamine (PDA). The effects of isolated conductive networks, different sizes of PS MPs, and different layers of FMs on the adsorption properties of FMs‐PDA‐Gr, as well as electrical performance for the obtained polypropylene‐PDA‐Gr composites, were studied. The composites displayed EMI SE for 29.3 dB in X‐band with 2 vol.% Gr content due to the isolated conductive network structure, which may be useful to the simultaneous elimination of garbage from electromagnetic pollution, FMs pollution, and MPs pollution to a certain degree.