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• Surface modification of Ti 3 C 2 T x MXene ink for 3D printing. • Improved interface interaction for PDMS/MXene stretchable conductors. • 3D printing of stretchable conductors with high self-supporting behaviour. • PDMS/MXene construct with appropriate stress-strain relations and electrical conductivity. Additive manufacturing has rapidly evolved over recent years with the advent of polymer inks and those inks containing novel nanomaterials. The compatibility of polymer inks with nanomaterial inks remains a great challenge. Simple yet effective methods for interface improvement are highly sought-after to significantly enhance the functional and mechanical properties of printed polymer nanocomposites. In this study, we developed and modified a Ti 3 C 2 MXene ink with a siloxane surfactant to provide compatibility with a polydimethylsiloxane (PDMS) matrix. The rheology of all the inks was investigated with parameters such as complex modulus and viscosity, confirming a self-supporting ink behaviour, whilst Fourier-transform infrared spectroscopy exposed the inks' reaction mechanisms. The modified MXene nanosheets have displayed strong interactions with PDMS over a wide strain amplitude. An electrical conductivity of 6.14 × 10−2 S cm−1 was recorded for a stretchable nanocomposite conductor containing the modified MXene ink. The nanocomposite revealed a nearly linear stress-strain relationship and a maximum stress of 0.25 MPa. Within 5% strain, the relative resistance change remained below 35% for up to 100 cycles, suggesting high flexibility, conductivity and mechanical resilience. This study creates a pathway for 3D printing conductive polymer/nanomaterial inks for multifunctional applications such as stretchable electronics and sensors. [ABSTRACT FROM AUTHOR]

In this paper, we study the concept of bilevel variational inequality featuring strongly monotone variational inequality over the solution set of the split variational inequality problem with multiple output sets in real Hilbert spaces. We propose two new two-step inertial iterative methods with self-adaptive step sizes for approximating the problem’s solution in the framework of Hilbert spaces. Our proposed algorithms eliminate the dependence on the norm of the transformation operators and the strongly monotone and Lipschitz continuous constants of the involved operators. Furthermore, strong convergence results are obtained without the co-coerciveness of the associated single-valued operators. Finally, we apply our result to study certain classes of split inverse problems and we present several numerical experiments to demonstrate the implementability of the proposed method.

In this paper, two relaxed CQ algorithms with non-inertial and inertial steps are proposed for solving the split feasibility problems with multiple output sets (SFPMOS) in infinite-dimensional real Hilbert spaces. The step size is determined dynamically without requiring prior information about the operator norm. Furthermore, the proposed algorithms are proven to converge strongly to the minimum-norm solution of the SFPMOS. Some applications of our main results regarding the solution of the split feasibility problem are presented. Finally, we give two numerical examples to illustrate the efficiency and implementation of our algorithms in comparison with existing algorithms in the literature.

Adhesion behavior of superhydrophobic (SH) surfaces is an active research field related to various engineering applications in controlled microdroplet transportation, self-cleaning, deicing, biochemical separation, tissue engineering, and water harvesting. Herein, we report a facile approach to control droplet adhesion, bouncing and rolling on properties of SH surfaces by tuning their air-gap and roughness-height by altering the concentrations of poly dimethyl-siloxane (PDMS). The optimal use of PDMS (4–16 wt %) in a dual-scale (nano- and microparticles) composite enables control of the specific surface area (SSA), pore volume, and roughness of matrices that result in a well-controlled adhesion between water droplets and SH surfaces. The sliding angles of these surfaces were tuned to be varied between 2 ± 1 and 87 ± 2°, which are attributed to the transformation of the contact type between droplet and surface from “point contact” to “area contact”. We further explored the effectiveness of these low and high adhesive SH surfaces in icing and deicing actions, which provides a new insight into design highly efficient and low-cost ice-release surface for cold temperature applications. Low adhesion (lotus effect) surface with higher pore-volume exhibited relatively excellent ice-release properties with significant icing delay ability principally attributed to the large air gap in the coating matrix than SH matrix with high adhesion (petal effect).

Here, we report a new method to prepare graphene from graphite by the liquid phase exfoliation process with sonication using graphene oxide (GO) as a dispersant. It was found that GO nanosheets act a as surfactant to the mediated exfoliation of graphite into a GO-adsorbed graphene complex in the aqueous solution, from which graphene was separated by an additional process. The preparation of isolated graphene from a single to a few layers is routinely achieved with an exfoliation yield of up to higher than 40% from the initial graphite material. The prepared graphene sheets showed a high quality (C/O ∼ 21.5), low defect (ID/IG∼ 0.12), and high conductivity (6.2 × 104S/m). Moreover, the large lateral size ranging from 5 to 10 μm of graphene, which is believed to be due to the shielding effect of GO avoiding damage under ultrasonic jets and cavitation formed by the sonication process. The thin graphene film prepared by the spray-coating technique showed a sheet resistance of 668 Ω/sq with a transmittance of 80% at 550 nm after annealing at 350 °C for 3 h. The transparent electrode was even greater with the resistance only 66.02 Ω when graphene is deposited on an interdigitated electrode (1 mm gap). Finally, a flexible sensor based on a graphene spray-coating polydimethylsiloxane (PDMS) is demonstrated showing excellent performance working under human touch pressure (<10 kPa). The graphene prepared by this method has some distinct properties showing it as a promising material for applications in electronics including thin film coatings, transparent electrodes, wearable electronics, human monitoring sensors, and RFID tags.

Herein, the visible light‐photocatalytic performance of synthesized ZnO/Gr composite materials with different Gr content under various conditions, i.e., pH, dye concentration, and different scavengers (to understand the photocatalytic activity mechanism) is systematically investigated. Photocatalytic performance is evaluated with the degradation of methylene blue (MB) in solution under sunlight irradiation. The presence of graphene (Gr) in the ZnO/Gr composites shows enhanced photocatalytic activity compared to pure ZnO under natural sunlight illumination. The highest photodegradation efficiency of ≈94% when the content of Gr is 1 wt% in comparison to ≈76% for the pure ZnO, corresponding to reaction rate constants of 0.01038 and 0.00615 min−1, respectively. Compared to recent publications, the degradation efficiency is high with relatively high dye concentration, low catalyst amount, and large solution volume. The enhanced visible light absorption and the reduction of bandgap value are attributed to the enhanced photocatalytic properties of the hybridized composite. Moreover, the investigation of the effect of scavenger substances shows that H2O2strongly enhanced their photocatalytic ability, suggesting that holes (h+) contribute as the reactive agent in the photodegradation process. Hybrid materials of ZnO and graphene (Gr) are developed for photocatalytic application. The presence of 1 wt% Gr in the ZnO/Gr composites results in enhancing 18% photocatalytic activity under sunlight illumination. The enhanced visible light absorption and the reduction of bandgap value are attributed to the enhanced photocatalytic properties of the hybridized composite.

To address high fire risks of flamable cellulosic materials, that can trigger easy combustion, flame propagation, and release of toxic gases, we report a new fire-retardant approach using synergetic actions combining unique properties of reduced graphene oxide (rGO) and hydrated-sodium metaborates (SMB). The single-step treatment of cellulosic materials by a composite suspension of rGO/SMB was developed to create a barrier layer on sawdust surface providing highly effective fire retardant protection with multiple modes of action. These performances are designed considering synergy between properties of hydrated-SMB crystals working as chemical heat-sink to slow down the thermal degradation of the cellulosic particles and gas impermeable rGO layers that prevents access of oxygen and the release of toxic volatiles. The rGO outer layer also creates a thermal and physical barrier by donating carbon between the flame and unburnt wood particles. The fire-retardant performance of developed graphene-borate composite and mechanism of fire protection are demonstrated by testing of different forms of cellulosic materials such as pine sawdust, particle-board, and fiber-based structures. Results revealed their outstanding self-extinguishing behavior with significant resistance to release of toxic and flammable volatiles suggesting rGO/SMB to be suitable alternative to the conventional toxic halogenated flame-retardant materials.

A practical methodto fabricate SWNT‐conducting polymer nano‐composites through poly(ionic liquid)‐mediated process is developed. It is demonstrated that the poly(ionic liquid) layer along and around SWNT not only gives the facility for good dispersion of SWNT, but also provides a functionality to interlink SWNT with conducting polymers.

The development of next‐generation of bioinks aims to fabricate anatomical size 3D scaffold with high printability and biocompatibility. Along with the progress in 3D bioprinting, 2D nanomaterials (2D NMs) prove to be emerging frontiers in the development of advanced materials owing to their extraordinary properties. Harnessing the properties of 2D NMs in 3D bioprinting technologies can revolutionize the development of bioinks by endowing new functionalities to the current bioinks. First the main contributions of 2D NMS in 3D bioprinting technologies are categorized here into six main classes: 1) reinforcement effect, 2) delivery of bioactive molecules, 3) improved electrical conductivity, 4) enhanced tissue formation, 5) photothermal effect, 6) and stronger antibacterial properties. Next, the recent advances in the use of each certain 2D NMs (1) graphene, 2) nanosilicate, 3) black phosphorus, 4) MXene, 5) transition metal dichalcogenides, 6) hexagonal boron nitride, and 7) metal–organic frameworks) in 3D bioprinting technology are critically summarized and evaluated thoroughly. Third, the role of physicochemical properties of 2D NMSs on their cytotoxicity is uncovered, with several representative examples of each studied 2D NMs. Finally, current challenges, opportunities, and outlook for the development of nanocomposite bioinks are discussed thoroughly. In the development of advanced materials, the unique properties of 2D nanomaterials (2D NMs) have proven to be a breakthrough. Thus, the integration of 2D nanomaterials with 3D printing has led to the development of advanced bioinks with added functionality. A comprehensive review of 2D NMs' contributions to the development of advanced bioinks is presented here.

3D Bioprinting In the development of advanced materials, the unique properties of 2D nanomaterials (2D NMs) have proven to be a breakthrough. Thus, the integration of 2D nanomaterials with 3D printing has led to the development of advanced bioinks with added functionality. A comprehensive review of 2D NMs' contributions to the development of advanced bioinks is presented in article number 2101439by Dusan Losic and co‐workers.

Laparoscopic pancreaticoduodenectomy (LPD) is a less invasive alternative to the traditional open pancreaticoduodenectomy (OPD) approach used to treat periampullary tumors. However, previous studies examining the advantages of this surgery over OPD have produced mixed results. Here, a retrospective observational approach was used to compare the short- and long-term outcomes of patients with periampullary tumors who underwent LPD or OPD at a single institution in Vietnam.

Peptic ulcer perforation (PUP) is one of the most common critical surgical emergencies. The omentum flap is commonly used to cover a PUP. However, the omentum cannot be used in cases of severe peritonitis or previous surgical removal. This is the first study conducted in Vietnam that was designed to analyse the outcomes of patients with PUPs who were treated using the falciform ligament.

Minimally invasive pancreaticoduodenectomy is a technically complex technique, that is being used to treat periampullary malignancy. We provide our experience with laparoscopic-assisted pancreaticoduodenectomy (LAPD) with statistics on the outcomes of periampullary cancer patients.

We present a practical method for fabricating carbon nanotubes (CNTs) and conducting polymer nanocomposites with enhanced thermal stability. The conducting nanocomposites were prepared by chemical modification of CNTs with poly(styrenesulfonate) (PSS) followed by an in situ polymerization of 3,4-ethylenedioxythiophene in the presence of poly(styrenesulfonate)-functionalized multiwalled carbon nanotubes (MWCNT-PSS). Morphological analysis of the resulting CNT-PSS poly(3,4-ethylenedioxythiophene) (PEDOT) composites revealed the presence of PSS on the outer surface of the tubes with a core-shell structure and the association of PEDOT with the PSS bound to CNT. In comparison to the control PEDOT:PSS films, the composite film showed improved electrical properties along with high thermal stability, thus demonstrating its potential for application to robust optoelectronic devices.

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