Natural high-porous diatomaceous-earth based self-floating aerogel for efficient solar steam power generation

The application of solar steam generation in seawater desalination is an effective way to solve the shortage of fresh water resources.At present,many kinds of photothermal conversion materials have been developed and used as evaporators in seawater desalination.However,some evaporators need additional thermal insulation or water supply devices to achieve efficient photothermal conversion.In addition,their complex,time consuming and no scalable preparation process,high cost of raw materials and poor salt resistance hinder the practical application of these evaporator.Owing to its distinctive nanoporous structure,diatomite as fossilized single-cells algae diatoms is a promising natural silica-based material for seawater desalination.They are taken from sea and that makes true sense to use them in the sea.Herein,we report the first example of synthesis robust three-dimensional(3D)natural-diatomite composite by assembling polyaniline nanoparticles covered diatomite into the polyvinyl alcohol pre-treated melamine foam frameworks and demonstrate its application as new evaporator for seawater desalination.The porous framework does not only improve the sunlight scattering efficiency,but also offer large network of channels for water transportation.The inherent mechanism behind salt desalination process involves the absorption of water molecules on the surface of the internal silica micro-nano pores,and evaporation under the heat induced by the polyaniline absorbed sunlight.Meanwhile,the metal ions are segregated by many available pores and channels to achieve the self-desalting effect.The developed evaporator possesses the superiority of multi-stage pore structure,strong hydrophilicity,low thermal conductivity,excellent light absorption,fast water transportation and salt-resistant crystallization as well as good durability.The evaporation rate without an additional device is found to be 1.689 kg m^(-2)h^(-1)under 1-Sun irradiation,and the energy conversion efficiency is as high as 95%.This work creates a platform and develops the prospect of employing green and sustainable natural-diatomite composite evaporator for practical applications of seawater desalination.

Controlling Drug Release from Titania Nanotube Arrays Using Polymer Nanocarriers and Biopolymer Coating

Titania nanotube arrays (TNT) prepared by self-ordering electrochemical anodization have attracted considerable attraction for the development of new devices for local drug delivery applications. Two approaches to extend drug release of water insoluble drugs by integration TNTs with polymeric micelles and biopolymer coatings are presented in this work. The proposed strategies emphasized on remarkable properties of these materials and their unique combination to design local drug delivery system with advanced performance. The first concept integrates TNTs with drug loaded polymeric micelles (Pluronic F127) as drug nanocarrier, until the second concept includes polymer coating of drug loaded TNT with biodegradable polymer (chitosan). The water insoluble, anti-inflammatory drug, indomethacin was used as a model drug. Both approaches showed a significant improvement of the drug release characteristics, with reduced burst release (from 77% to 39%) and extended overall release from 9 days to more than 28 days. These results suggest the capability of TNT based systems to be applied for local drug delivery deliver over an extended period with predictable kinetics that is particularly important for bone implant therapies.

3D printing interface-modified PDMS/MXene nanocomposites for stretchable conductors

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.