Sugar Template Research Articles

Multi-Dimensionally Functionalized Pressure Sensor for Human Motion Detection Based on 1D AgNWs/2D rGO-Coated 3D Porous Sponge.

This study presents a conductive-type pressure sensor based on a conductive composite of 1D/2D nanomaterials coated onto a 3D nonconductive polymer structure with various pores. A 3D porous elastomer for the substrate was fabricated by using a sugar template, which led to an increased mechanical deformation range. The sugar template enhanced the surface roughness of the polymer, resulting in an improvement in the adhesion of nanomaterials to the polymer surface. Subsequently, it was functionalized by coating with hybrid nanomaterials of 1D silver nanowires (AgNWs) and 2D reduced graphene oxide (rGO) through a dip-coating process. When pressure is applied, the rGO/AgNWs/ecoflex pressure sensor deforms along the direction of the applied force, causing the conductive multidimensional nanomaterials to come into contact. Consequently, the improved networks between the two nanomaterials expanded the current paths, increasing the current detected through the electrodes attached to the sensor. The rGO/AgNWs/ecoflex pressure sensor, with its porous structure within the flexible ecoflex, demonstrated a high sensitivity (up to 2.29 kPa-1) over a wide detection range of 0-120 kPa. This enables the monitoring of a wide range of motions, including small pressures such as subtle touch, respiratory vibrations, and drinking, as well as large pressures such as human bodily movements, finger/arm bending, and foot pressure, making it an excellent candidate for applications requiring precise pressure detection.

Lightweight, Highly Extensible, and Anti‐Leak Liquid Metal Elastomer Composites with an Interpenetrating Architecture

In this study, a reformed sugar template‐based method is employed to prepare gallium‐based liquid‐metal‐filled elastomer composites (LMECs), which allows the uniform dispersion of LM droplets within the elastomer matrix in the form of an interpenetrating morphology. In the current preparation, a portion of the liquid metal (LM) is extracted from the elastomer foam following a complete vacuum infusion, resulting in a 10% volume fraction of LM droplets remaining. These droplets exhibit strong adhesion to the inner surfaces of the elastomer foams through the Ga2O3 layer. Nevertheless, the electrical and thermal conductivities are found to be 0.72 × 103 S m−1 and 0.48 W m−1 K−1, respectively. The mechanical performance, piezo‐resistive effect, and thermal conductivity are measured to establish the structure–property relationships. Furthermore, the intrinsic microphysical mechanisms are identified from their distinctive architectures. The reformation of the conventional sugar template approach results in the low concentration and homogeneous dispersion of LM droplets, endowing the resulting LMECs with lightweight and versatile properties, and also mitigating LM leakage to some extent. Herein, this work may prove instrumental in the development of stretchable electronics, soft robots, and multifunctional materials with interpenetrating networks.

Inside-out templating: A strategy to decorate helical carbon nanotubes and 2D MoS2 on ethyl cellulose sponge for enhanced oil adsorption and oil/water separation

Ethyl cellulose (EC)-based composite sponges were developed for oil spillage treatment. The EC sponge surface was decorated with helical carbon nanotubes (HCNTs) and molybdenum disulfide (MoS2) (1 phr) using the inside-out sugar templating method. The inside surface of a sugar cube was coated with HCNTs and MoS2. After filling the sugar cube pores with EC and the subsequent sugar leaching, the decorating materials presented on the sponge surface. The EC/HCNT/MoS2 sponge had a high level of oil removal based on its adsorption capacity (41.68 g/g), cycled adsorption (∼75–79 %), separation flux efficiency (∼85–95 %), and efficiency in oil/water emulsion separation (92–94 %). The sponge maintained adsorption capacity in acidic, basic, and salty conditions, adsorbed oil under water, and functioned as an oil/water separator in a continuous pump-assisted system. The compressive stress and Young's modulus of the EC sponge increased following its decoration using HCNTs and MoS2. The composite sponge was robust based on cycled compression and was thermally stable up to ∼120 οC. Based on the eco-friendliness of EC, the low loading of HCNTs and MoS2, and sponge versatility, the developed EC/HCNT/MoS2 sponge should be good candidate for use in sustainable oil adsorption and separation applications.

Single-Material Solvent-Driven Polydimethylsiloxane Sponge Bending Actuators.

Soft robots mimic the agility of living organisms without rigid joints and muscles. Continuum bending (CB) is one type of motion living organisms can display. CB can be achieved using pneumatic, electroactive, or thermal actuators prepared by casting an active layer on a passive layer. The corresponding input actuates only the active layer in the assembly resulting in the bending of the structure. These two different layers must be laminated well during manufacturing. However, the formed bilayer can still delaminate later, and the detachment hampers the actuator's reversible, long-time use. An approach to creating a single material bending actuator was previously reported, for which spatial gradient swelling was used. This authentic approach allows a single material to be manufactured as a bending actuator, allowing easy access to such actuators without lamination. In this study, we show spatial porosity differences in the sponges of polydimethylsiloxane (PDMS) (a common material in soft robotics) can be used to create the required anisotropy for bending. The spongy polymers are manufactured through table sugar templates and actuated by (organic) solvent absorption/desorption. This enables some versatility in the mechanical properties, shape, actuation force, and actuation speed. The one-material system's straightforward production and seamless nature are advantageous for reversible and repetitive bending. This simple method can further be developed in hydrogels and polymers for soft robotics and functional materials.

Non-Aqueous Poly(dimethylsiloxane) Organogel Sponges for Controlled Solvent Release: Synthesis, Characterization, and Application in the Cleaning of Artworks.

Polydimethylsiloxane (PDMS) organogel sponges were prepared and studied in order to understand the role of pore size in an elastomeric network on the ability to uptake and release organic solvents. PDMS organogel sponges have been produced according to sugar leaching techniques by adding two sugar templates of different forms and grain sizes (a sugar cube template and a powdered sugar template), in order to obtain materials differing in porosity, pore size distribution, and solvent absorption and liquid retention capability. These materials were compared to PDMS organogel slabs that do not contain pores. The sponges were characterized by Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and compared with PDMS slabs that do not contain pores. Scanning electron microscopy (SEM) provided information about their morphology. X-ray micro-tomography (XMT) allowed us to ascertain how the form of the sugar templating agent influences the porosity of the systems: when templated with sugar cubes, the porosity was 77% and the mean size of the pores was ca. 300 μm; when templated with powdered sugar, the porosity decreased to ca. 10% and the mean pore size was reduced to ca. 75 μm. These materials, porous organic polymers (POPs), can absorb many solvents in different proportions as a function of their polarity. Absorption capacity, as measured by swelling with eight solvents covering a wide range of polarities, was investigated. Rheology data established that solvent absorption did not have an appreciable impact on the gel-like properties of the sponges, suggesting their potential for applications in cultural heritage conservation. Application tests were conducted on the surfaces of two different lab mock-ups that simulate real painted works of art. They demonstrated further that PDMS sponges are a potential innovative support for controlled and selective cleaning of works of art surfaces.

Hydrogen production via dark fermentation by bacteria colonies on porous PDMS-scaffolds

The development of biofuels and the question of finding renewable energy sources are important issues nowadays, due to the increasing shortage of other supplies. Hydrogen has gained very much attention as biofuel, as it is highly energetic and a clean energy source. A very interesting method to produce hydrogen is dark fermentation. It generates a clean energy from organic wastes with low value and at low energy requirements. The production of hydrogen and bio-hydrogen from waste and wastewaters can have a positive environmental impact in terms of creation of highly effective energy fuel and reduction of waste. Due to their nutrients, organic waste and wastewaters are suitable substrates to obtain bio-hydrogen. In this paper we investigate the behaviour and the stability of porous scaffolds containing iron oxide particles in a dark fermentation environment and explore the possibility of hosting mixed cultures of clostridia on them, aiming to an increase in hydrogen production. We address the effect of embedding hematite particles (in different concentrations) in the scaffolds, to see whether there is an increase in bio-hydrogen-production. This latter can be enhanced, if particles of various metal oxides are present, as they can increase bacterial growth and encourage the bioactivity of species that produce hydrogen. The scaffolds analysed consist of polydimethylsiloxane (PDMS) containing Fe2O3 particles and were produced via the sugar template method. X-ray diffraction patterns, SEM images as well as dark fermentation tests in batch procedure are presented and discussed. Bacteria colonies could be detected after long treatment in municipal wastewater and production of biohydrogen was ascertained for all samples investigated.

Effect of poling on the dielectric properties of synthesized β-poly (vinylidene fluoride) foam

A straightforward scalable method for synthesizing β-poly (vinylidene fluoride) polymer foam from a sugar template has been used. A characteristic β-phase of the foam was confirmed by infrared and micro-Raman spectroscopy with significant enhancement observed after poling. The electrical polarization of the foam revealed a ferroelectric nature with dielectric strength higher than 30 kV/cm which is close to the commercial value. Poled samples had a dielectric constant of 5.5, higher than the value of the unpoled sample (3.05). These values appear stable over the low-frequency range from 1 kHz to 1 MHz. Significant reverse behavior was observed at higher frequencies from 300 GHz to 3 THz frequencies. It was found that the open-cell foam with a porosity of 88% has the lowest dielectric constant value (1.07 at 1.8 THz, reaching 1.04 at 2.9 THz) compared to the foam with 20% porosity (2.17 at 1 THz, reaching 1.83 at 3 THz). Furthermore, the Maxwell Garnett model, in conjunction with THz imaging, confirmed the impact of porosity on dielectric properties. These findings pave the way for the efficient fabrication of ferroelectric porous polymer structures that can be used in dielectric switching at the kHz–THz frequency range.

Design of healable, porous polyurethane with large ionic liquids loading amounts towards ultra-durable pressure sensor

Flexible intelligent sensors have got booming development over the past decades, yet, it is still a huge challenge to construct advanced sensors with long service life and superb durability. Herein, a novel porous capacitance pressure sensor with ultra-durability via sugar template method was prepared successfully by impregnating non-volatile, highly conductive ionic liquids (ILs) into polyurethane (PU-DBTDA5) matrix. As a consequence of the rich hydrogen bonding networks and dynamic hindered urea bond in the polymer chain, the as-prepared PU-DBTDA5 matrix shows excellent self-healing ability (99 %). The ionic liquid-soluble polyethylene glycol (PEG1000) serving as soft segment endows PU-DBTDA5 with ultra-absorption ability of ILs (absorbing ILs over three times to its own weight within 5 min). The pressure sensor with porous structure shows outstanding anti-fatigue ability as well as good sensitivity (S1 = 0.82 kPa−1, S2 = 1.04 kPa−1), and it can even monitor tiny strain as low as 0.5 %. More importantly, due to the well combination of the PU-DBTDA5 with excellent self-healing ability and the non-volatile ionic liquids, not only the healed sensor, but the sensor stored at room environment over 100 days both exhibit stable electronic signals similar to that of freshly-prepared foam sensor in 3000 uninterrupted compression tests, being strong evidence of its ultra-durability.

Dual 3D networks of graphene derivatives based polydimethylsiloxane composites for electrical insulating electronic packaging materials with outstanding electromagnetic interference shielding and thermal dissipation performances

Research on electronic packaging materials with high electromagnetic interference (EMI) shielding, thermal conductivity, and electrical insulating properties has been flourishing in recent years. In this work, dual three-dimensional (3D) structures of graphene nanoplatelets (GnP) and graphene fluoride (GF) were fabricated in the polydimethylsiloxane (PDMS) composites for electronic packaging materials with superior EMI shielding effectiveness (SE), thermal conductivity, and electrically insulating. The first 3D structure of the porous GnP@PDMS foams was fabricated using the sugar template method. The GF/PDMS solution was then infiltrated into the GnP@PDMS foam by the vacuum infiltration method to create the second 3D network of GF in the GnP@PDMS/GF composites. The prepared porous GnP30@PDMS foam exhibits an EMI SE of 51.26 dB with 30 wt% of GnP. In addition, the introduction of the second 3D network of GF/PDMS plays a vital role to improve the thermal conductivity and electrical insulating properties of the GnP30@PDMS/GF composites. The GnP30@PDMS/GF8 composites showed a thermal conductivity of 1.47 W·m−1·K−1 which is enhanced by 568 % in comparison to the pure PDMS and excellent electrical insulating properties as high as 2.82 × 10−10 S·cm−1 and maintained high EMI SE of 50.13 dB. The extraordinary EMI SE of the GnP@PDMS/GF composites is favorably correlated to the porous interconnected network of GnP while the enhanced thermal conductivity is attributed to the dual 3D thermoconductive channels of GnP and GF. Additionally, the GnP@PDMS/GF8 composites are demonstrated to have outstanding mechanical flexibility, thermal stability, and heat dissipating capability. Therefore, the developed GnP@PDMS/GF composites have great prospects in the field of electronic packaging materials.

A Sensitive and Flexible Poroelastic Barium Titanate Matrix for Pressure Sensing Applications

This letter reports on poroelastic barium titanate matrix (PBM) for flexible pressure sensor applications. The fabrication of PBM is a simple and cost-effective process that allows an optimized composition of polydimethylsiloxane (PDMS) and barium titanate (BTO) to penetrate through the sugar template via capillary action. The fabricated PBM undergoes large deformation if compared to the state-of-the-art pressure sensors. Around a two-fold increase in sensitivity is observed with the appropriate weight percent (%) of BTO in PDMS and the %porosity in the PBM structure. The PBM generates a peak voltage of ∼1.1 V, whereas the nonporous composite (BTO+PDMS) generates only ∼500 mV. The response of PBM is highly linear (coefficient of linearity 0.983) and repeatable with a deviation of 0.47%. Furthermore, the operating range of PBM is 5–100 kPa. Finite element simulations are carried out to find the relation between the substrate porosity, %weight ratio of BTO, and the generated voltage. The optimized PBM can be exploited for applications, such as gait biomechanics.

Fabrication, Properties, and Performance of Polymer-Clay Nanocomposites for Organic Dye Removal from Aqueous Media

Methylene blue dye (MB dye) is a harmful contaminant for wastewater streams of industries and is harmful to human and aquatic life. An ecofriendly sugar templating process was used to generate porous bentonite/polydimethylsiloxane (PB) and porous magnetite nanoparticles/bentonite/polydimethylsiloxane (PBNP) composite absorbents to remove MB dye in this study. During the infiltration of PDMS solution into the sugar template in the vacuum chamber, bentonite and magnetite particles were integrated on the surface of the PDMS, and the porous structure was generated during the leaching out of sugar particles in water. The absorbents were characterized using Fourier infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The absence of the methyl bond at 2924 cm-1 and phenol bond at 3325 cm-1 in the FTIR spectra of the formed membrane proves that the food grade sugar was completely removed. The SEM images confirm that porosity was achieved as well as uniform mixing of the in the formation of composite. MB dye was effectively removed from wastewater using the as-prepared composite as absorbent. The removal efficiencies of the composite PBNP and PB were ~91% and ~85%, respectively. The experimental data was applied to pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models as well as the Dubinin-Radushkevich, Harkins-Jura, and Elovich models for the adsorption isotherm. The data was found to fit the pseudo-second-order and Elovich models, respectively. The results show that the presence of magnetite nanoparticles improved MB dye removal significantly.

Multifunctional conductive sponge with excellent superhydrophobicity, piezoresistivity, electro/light to heat conversion, and oil/water separation performance

Flexible porous conductive composites have been widely applied for wearable sensing devices and there is continuous exploration towards multi-functionalization of porous conductive composites. In this work, through sugar template method and following immersion assisted reduction, polydimethylsiloxane (PDMS) sponge embedded with carbonyl iron (CI) was successfully anchored with silver nanoparticles (AgNPs) binded with block copolymer polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene (SEBS). A superhydrophobic multifunctional sponge type conductive composites (SCC) was prepared (CI-PDMS/AgNPs-SEBS Sponge, abbreviated as CP/AgE Sponge). CP/AgE sponge had excellent superhydrophobic properties (water contact angle≈153°), efficient Joule heating (1.6 V, 101 °C within 180 s) and photothermal conversion capabilities (250 mW/cm2, 102 °C within 40 s). The CP/AgE sponge pressure sensor had excellent piezoresistive properties, including high sensitivity (3.8 kPa−1), wide detection range (160 kPa) and robust stability when subjected to 1000 compression-release cycles, which could be further utilized to accurately and reliably monitor the changing biophysical signals. Besides, CP/AgE sponge had high oil/water separation efficiency as well as magnetically guided waste oil adsorption ability. This work provides a new strategy for preparing a conductive sponge with superhydrophobicity and enriched functionality, which has broad applications in the fields of next generation multifunctional flexible electronics, effective oil/water separation and smart protective skins.

A supersensitive wearable sensor constructed with PDMS porous foam and multi-integrated conductive pathways structure

In recent years, wearable multifunctional strain sensors have attracted attention for their promising applications in wearable electronics and portable devices. To achieve a high-performance wearable strain sensor with a wide sensing range and high gauge factor (GF), wisely choosing appropriate conductive materials and a rational structural design is essential. Herein, we develop a supersensitive sensor that contains one-dimensional conductive material CNT and two-dimensional material MXene built on a PDMS porous foam that is made based on a sugar template. The one-dimensional carbon nanotube (CNT) functionalizes as a conductive scale layer through solvent swelling and evaporation on the surface of the PDMS skeleton. The two-dimensional MXene is applied on top of the CNT layer to form final conductive pathways. The PDMS/CNT@MXene (PCM) sensor has a wide sensing range (150%), high sensitivity (GF = 26438), rapid response speed (response/recovery time of 60/71 ms), and exceptional durability (>1000 cycles) owing to its unique porous structure with scale layers and graded fracture of conductive pathways. Moreover, the PCM sensor is capable of monitoring subtle and significant human activities and is used for wireless sensing and medical diagnostics, even for solvent identification. The superior performance of the PCM sensor provides vast application potential in human movement, health monitoring, and warning devices.

Stretchable translucent nanocomposite membranes with 3D heterogeneous interfaces derived from sugar templates for mechano-responsive optical applications

Stretchable nanocomposites with embedded three-dimensional (3D) heterogeneous interfaces that can dynamically adjust optical transparency over a wide range through mechanical deformation are promising as key materials for smart windows and flexible sensors. However, it is still difficult to inexpensively and easily fabricate these nanocomposites because previously reported fabrication methods rely mainly on complex lithography. Here, we propose an efficient method for fabricating stretchable nanocomposites that dynamically increase opacity when stretched. First, a microporous PDMS sponge is prepared by using a plate-shaped sugar cube prepared through a wet agglomeration process as a template. A 3D continuous ultrathin (∼60 nm) alumina layer is then conformally deposited onto the PDMS sponge via atomic layer deposition. Complete filling of the porous network inside the prepared specimen with PDMS yields a translucent nanocomposite embedded with a 3D continuous alumina layer. When the resulting nanocomposite is stretched, the significant difference in modulus between PDMS and alumina results in the generation of numerous scattering voids at the 3D continuous interface of PDMS and alumina. Depending on the thickness of the specimen, the initial transmittance and the degree of decrease in transmittance during deformation can be controlled. These results will provide an opportunity to economically fabricate advanced nanocomposites for mechanically driven smart window systems or optical strain gauges, as demonstrated in this study.

Biorhythm paralleled release of pheromone by photothermal conversion for Long-term bark beetle control

The spruce bark beetle Ips typographus, as the most notorious pest in Eurasia spruce forest ecosystem, mainly feed on phloem of spruce tree trunk. The concealment of their habit makes regulation of insect population a difficulty to cope with, contributing to spruce forest recession, destruction of environment balance and forest transformation from carbon sinks into carbon source. Based on the cross point between the biorhythm of the I. typographus and photothermal material, description herein was a novel sunlight-triggered biorhythm-paralleled photothermal sponge (BPPS) for continuous control of I. typographus. Three steps including preparation of sugar template based porous polyurethane (PU) sponge, polypyrrole (PPy) modification and pheromone filling were involved in material manufacturing. The attractant and repellant agents were employed into the PU separately to realize a comprehensive regulation on I. typographus behavior. Laboratory simulation and forest field experiments illustrated that both the rapid release within a short period and long-term effectiveness in 21 days were verified. Due to the advantages of designability, cost-effectiveness and environmental friendliness of our sustained-release sponge, this manufacturing strategy offers great promise for generating photothermal responsive sustained-release material, shedding light on long-term control of injurious trunk borers and environmental protection.

4,6-O-Phenylethylidene Acetal Protected D-Glucosamine Carbamate-Based Gelators and Their Applications for Multi-Component Gels.

The self-assembly of carbohydrate-based low molecular weight gelators has led to useful advanced soft materials. The interactions of the gelators with various cations and anions are important in creating novel molecular architectures and expanding the scope of the small molecular gelators. In this study, a series of thirteen new C-2 carbamates of the 4,6-O-phenylethylidene acetal-protected D-glucosamine derivatives has been synthesized and characterized. These compounds are rationally designed from a common sugar template. All carbamates synthesized were found to be efficient gelators and three compounds are also hydrogelators. The resulting gels were characterized using optical microscopy, atomic force microscopy, and rheology. The gelation mechanisms were further elucidated using 1H NMR spectroscopy at different temperatures. The isopropyl carbamate hydrogelator 7 formed hydrogels at 0.2 wt% and also formed gels with several tetra alkyl ammonium salts, and showed effectiveness in the creation of gel electrolytes. The formation of metallogels using earth-abundant metal ions such as copper, nickel, iron, zinc, as well as silver and lead salts was evaluated for a few gelators. Using chemiluminescence spectroscopy, the metal–organic xerogels showed enzyme-like properties and enhanced luminescence for luminol. In addition, we also studied the applications of several gels for drug immobilizations and the gels showed sustained release of naproxen from the gel matrices. This robust sugar carbamate-derived gelator system can be used as the scaffold for the design of other functional materials with various types of applications.

Porous polydimethylsiloxane composite filled with graphene oxide and gold nanoparticles produced by laser ablation in liquids

The design of new materials with improved mechanical and biological properties is a major interest in biomedical applications. This paper presents the synthesis of macro-porous polydimethylsiloxane (PDMS) sponge composites as potential materials for tissue engineering. PDMS sponge with pores size ranging between 50 and 900 μm was produced using the sugar templating process. The sponges were decorated with graphene oxide and gold nanoparticles created by the laser ablation in liquid and then they were morphologically, mechanically and biologically characterized. The optical properties of all the solutions containing nanoparticles were studied with the UV-ViS spectroscopy. The biological behaviour and performance of native PDMS, PDMS decorated with graphene oxide, and with graphene oxide and gold nanoparticles were compared. Results show that the composites and equally as important the adopted processing are both biocompatible. The quality of filler dispersion in the porous composites was observed by scanning electron (SEM) and atomic force (AFM) microscopies. The biocompatibility of the composites and of the preparation procedure was confirmed by monitoring the cytotoxicity of the composites for different types of cell cultures.

Preparation of floating PDMS sponge catalysts embedded with copper oxide(s): A prelude to the study of its application toward the effective rhodamine B degradation by sonochemical method

In this study, copper oxide (s) embedded polydimethylsiloxane (PDMS) sponge catalysts have been prepared and demonstrated as an efficient heterogeneous catalyst for the Fenton-type degradation of rhodamine B (RB) in an aqueous solution, in which RB was selected as a representative pollutant. Each Cu2O, CuO, and a mixture of Cu2O and CuO embedded with the PDMS sponge were synthesized by respective copper oxides onto a sugar template, followed by the addition of PDMS with an elastomer, degassing, curing, removing sugar templates, and drying in a hot air oven. The resulting catalysts were characterized using FTIR, SEM-EDS, and ICP-OES methods. The as-synthesized catalysts were used to degrade RB utilizing normal stirring and sonochemical methods under a diverse range of reaction conditions. The sonochemical method effectively removed RB (> 98% of 125 mg L–1) from the aqueous solution. Moreover, RB degradation follows relatively faster kinetics (3–9 h) with 750 µL volume of H2O2, and degradation remains consistent with different optimized pH conditions (4–7). This degradation process followed a first order kinetic model with higher r2 values. Experimental results suggest that RB degradation is linked to the interplay among all reagents and coincides with previously reported degradation mechanisms. This sonochemical degradation process followed a first-order kinetic model and the materials were reusable for more than 10 cycles. The facile synthesis, high catalytic performance, reusability, durability, and easy recoverability of the as-prepared catalyst are promising for environmental catalytic pollutant degradation applications in the treatment of organic pollutants at diverse operating conditions.

Nanoparticles embedded in a sponge of polydimethylsiloxane by laser ablation in liquid

This work describes the preparation of polydimethylsiloxane (PDMS) sponge with pore sizes of about 50 and 900 µm. The sponges synthetized by the sugar template process were embedded with graphene oxide (GO) and gold nanoparticles (AuNPs) previously produced by laser ablation in liquid. The suspension containing graphene oxide and gold nanoparticles were optically characterized by UV-ViS spectroscopy. The dispersion of the nanoparticles in the PDMS sponges was observed by the Scanning Electron Microscopy (SEM). The biocompatibility of virgin PDMS, PDMS filled with graphene oxide, and with graphene oxide and gold nanoparticles was studied for different types of cell cultures. This study has allowed us to confirm that the PDMS sponge is a good matrix for embedding AuNPs and has highlighted as the presence of GO hinders the aggregation of AuNPs avoiding the use of surfactant and allowing their use in biological applications.

Polycaprolactone/ZIF-8 nanocomposites fabricated for oil sorption and antibacterial applications

Hydrophobic sponges were fabricated of zeolitic imidazolate framework-8 (ZIF-8) and polycaprolactone (PCL) nanocomposites, PCL/x%ZIF-8 (x = 10, 30, and 50), through the sugar template strategy. The as-prepared nanocomposites were investigated by FTIR (Fourier-transform infrared), XRD (X-ray diffraction), SEM (scanning electron microscope), and EDS (energy-dispersive X-ray spectroscopy) mapping techniques. The obtained results demonstrated the successful incorporation of ZIF-8 into the PCL matrix. The sponge-like structure was confirmed by SEM images. The mass ratio effects of ZIF-8 and PCL on the oil sorption efficiency and antibacterial activity were studied. The nanocomposites exhibited suitable efficiency for adsorbing various oils, including olive oil, sunflower oil, and motor oil. Additionally, the sorbents can be recovered and reused easily. The results from oil adsorption investigations exhibited that the PCL/50%ZIF-8 has promising efficiency as an oil sorbent (12.1 g g−1). Also, the PCL/x%ZIF-8 composites (PCL/30%ZIF-8 and PCL/50%ZIF-8) resulted in a lethal effect on E. coli cells, suggesting their potential applicationas novel antibacterial materials for drinkingwater disinfection.