The energy harvesting provided by
wearable triboelectric devices
represents a promising procedure that circumvents typical drawbacks
of conventional batteries in several applications. The development
of wearable triboelectric generators with modified cotton in the presence
of conductive and antibacterial agents can be considered an important
step toward developing autonomous devices to be applied in electrically
driven antibacterial treatments. The antibacterial properties of polypyrrole
and its high conductivity were explored for the production of the
induction layer of a single-electrode triboelectric generator that
introduces advantages relative to direct contact with the skin, which
is critical for the treatment of several infections. The open-circuit
voltage in the order of 670 V and inhibition haloes in the order of
17 mm (against Staphylococcus aureus) confirm the multifunctional activity of the modified cotton that
can be applied to the harvesting of energy and integrated into the
inhibition of bacterial growth provided by polypyrrole-based systems.
The required treatment and monitoring of contaminants in wastewater reinforces the development of low-cost adsorbents/ chemosensors, introducing advantages relative to the detection/removal of toxic metals and dyes. Herein, it is reported a two-step process of fabrication of fluorescent carbon dots via the hydrothermal treatment of amino acids for the following encapsulation in electrospun fibers. The prominent anionic behavior of electrospun fibers of Eudragit L100 was explored for adsorption of cationic dyes (methylene blue and crystal violet)-with the prevailing electrostatic interaction of parts being favored by the formation of monolayers on the surface of adsorbents. On the other hand, the controlled release of carbon dots (CDs) from fibers to the reactor can be explored for a second application: the nitrogen ligands from released glycinebased carbon dots can be explored to indicate the presence of metal ions in aqueous solution. Our experiment resulted in a quenching in the fluorescence of the CDs in order of 90% in the emission of particles in the response of the presence of Fe 3+ ions, characterizing a promising perspective for this experimental system.
A biomass amino silica-functionalized
material was successfully
prepared by a simple sol–gel method. 3-Aminopropyltriethoxysilane
(APTES) was added to a tannin-rich grape residue to improve its physicochemical
properties and enhance the adsorption performance. The APTES functionalization
led to significant changes in the material’s characteristics.
The functionalized material was efficiently applied in the removal
of methyl orange (MO) due to its unique characteristics, such as an
abundance of functional groups on its surface. The adsorption process
suggests that the electrostatic interactions were the main acting
mechanism of the MO dye removal, although other interactions can also
take place. The functionalized biomass achieved a very high MO dye
maximum adsorption capacity (
Q
max
) of
361.8 mg g
–1
. The temperature positively affected
the MO removal, and the thermodynamic studies indicated that the adsorption
of MO onto APTES-functionalized biomass was spontaneous and endothermic,
and enthalpy is driven in the physisorption mode. The regeneration
performance revealed that the APTES-functionalized biomass material
could be easily recycled and reused by maintaining very good performance
even after five cycles. The adsorbent material was also employed to
treat two simulated dye house effluents, which showed 48% removal.
At last, the APTES biomass-based material may find significant applications
as a multifunctional adsorbent and can be used further to separate
pollutants from wastewater.
The use of unmodified and chemically treated natural fibers for water remediation (removal of chemical residues/oil spills and organic wastewater from water) is a significant and low-cost strategy to reduce the contamination of aquifers with metal ions, as well as marine environments with oil spills and water bodies with organic dyes. Furthermore, synthetic fibers exhibit a superior performance owing to their tunable surface area and superhydrophobic/swelling properties. This review summarizes the most recent advances in natural fiber-based biosorbents and synthetic fiber mats since the efficient removal of toxic compounds depend on adequate incorporation of functional groups on the fiber surface for mutual electrostatic and diffusion of contaminants into the fibrils. The most relevant results in the removal of oil, trace metal ions, and organic dyes are presented and evaluated. The evaluation is done according to the strategies for chemical modification of raw materials by the reuse of plastics or conventional electrospinning techniques to support the hierarchical growth of more complex chemical structures.
The development of implantable and wearable electronics
and the
concept of the internet of things proved a recent burgeoning growth
with different applications. However, the integration of electrically
driven devices depends on hard components that must be conveniently
substituted by flexible and more efficient devices. Herein, the development
of a simple and low-cost all-in-one flexible system based on triboelectric
generators that harvest energy from the skin contact with the device
is proposed and makes possible the storage of this energy in a supercapacitor
prepared with the same support applied as collectors of triboelectric
nanogenerators (eggshell membranes modified with graphene nanoplatelets
and polypyrrole). This integrated prototype for the energy harvesting/storage
device with the characteristic flexibility of natural eggshell membranes
introduces promising properties of an autonomous device able to drive
electronic devices integrated into flexible substrates.
Metal-free triboelectric nanogenerators (TENGs) with properties of comfort, mechanical resistance, and low cost of preparation have been explored as alternative and advantageous systems for incorporation in wearables and sensors. Herein, the production of an all-silicone rubber TENG that explores the percolation threshold of graphite flakes to create accessible current pathways into the membrane, acting as an adequate electrode with high conductivity, and adequate surface modification to provide a high charge transfer rate from a single electrode TENG that explores the human skin as a tribopositive layer are proposed. The proposed all-silicone rubber TENG presented an outstanding performance of 308.7 V for output voltage and power density of 197.2 μW/cm 2 for samples prepared with a silicone rubber layer applied as a tribolayer and modified electrode.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.