Cellulose-based materials in wastewater treatment of petroleum industry

The most abundant natural biopolymer on earth, cellulose fiber, may offer a highly efficient, low-cost, and chemical-free option for wastewater treatment. Cellulose is widely distributed in plants and several marine animals. It is a carbohydrate polymer consisting of β-1,4-linked anhydro-D-glucose units with three hydroxyl groups per anhydroglucose unit(AGU). Cellulose-based materials have been used in food, industrial, pharmaceutical, paper, textile production, and in wastewater treatment applications due to their low cost, renewability,biodegradability, and non-toxicity. For water treatment in the oil and gas industry, cellulose-based materials can be used as adsorbents, flocculants, and oil/water separation membranes. In this review, the uses of cellulose-based materials for wastewater treatment in the oil & gas industry are summarized, and recent research progress in the following aspects are highlighted: crude oil spill cleaning, flocculation of solid suspended matter in drilling or oil recovery in the upstream oil industry, adsorption of heavy metal or chemicals, and separation of oil/water by cellulosic membrane in the downstream water treatment.

Robust,Breathable and Flexible Smart Textiles as Multifunctional Sensor and Heater for Personal Health Management

Smart textiles with high sensitivity and rapid response for various external stimuli have gained tremendous attentions in human healthcare monitoring,personal heat management,and wearable electronics.However,the current smart textiles only acquire desired signal passively,regularly lacking subsequent on-demand therapy actively.Herein,a robust,breathable,and flexible smart textiles as multi-function sensor and wearable heater for human health monitoring and gentle thermotherapy in real time is constructed.The composite fiber as strain sensor(CFY@PU)was fabricated via warping carbon fiber yarns(CFY)onto polyurethane fibers(PU),which endowed composite fiber with high conductivity,excellent sensitivity(GF=76.2),and fantastic dynamic durability(7500 cycles)in strain sensing.In addition,CFY@PU can detect various degrees of human movements such as elbow bending,swallowing and pulse,which can provide effective information for disease diagnosis.More surprisingly,weaving CFY@PU into a fabric can assemble highly sensitive pressure sensor for remote communication and information encryption.Warping CFY onto Kevlar would obtain temperature-sensitive composite fiber(CFY@Kevlar)as temperature sensor and wearable heater for on-demand thermotherapy,which provided unique opportunities in designing smart textiles with ultrahigh sensitivity,rapid response,and great dynamic durability.

Flexible,anti-damage,and non-contact sensing electronic skin implanted with MWCNT to block public pathogens contact infection

If a person comes into contact with pathogens on public facilities,there is a threat of contact(skin/wound)infections.More urgently,there are also reports about COVID-19 coronavirus contact infection,which once again reminds that contact infection is a very easily overlooked disease exposure route.Herein,we propose an innovative implantation strategy to fabricate a multi-walled carbon nanotube/polyvinyl alcohol(MWCNT/PVA,MCP)interpenetrating interface to achieve flexibility,anti-damage,and non-contact sensing electronic skin(E-skin).Interestingly,the MCP E-skin had a fascinating non-contact sensing function,which can respond to the finger approaching 0−20 mm through the spatial weak field.This non-contact sensing can be applied urgently to human–machine interactions in public facilities to block pathogen.The scratches of the fruit knife did not damage the MCP E-skin,and can resist chemical corrosion after hydrophobic treatment.In addition,the MCP E-skin was developed to real-time monitor the respiratory and cough for exercise detection and disease diagnosis.Notably,the MCP E-skin has great potential for emergency applications in times of infectious disease pandemics.

Versatile sensing devices for self-driven designated therapy based on robust breathable composite films

Flexible wearable electronics were developed for applications such as electronic skins,human-machine interactions,healthcare monitoring,and anti-infection therapy.But conventional materials showed impermeability,single sensing ability,and no designated therapy,which hindered their applications.Thus it was still a great challenge to develop electronic devices with multifunctional sensing properties and self-driven anti-infection therapy.Herein,flexible and breathable on-skin electronic devices for multifunctional fabric based sensing and self-driven designated anti-infection therapy were prepared successfully with cellulose nanocrystals/iron(Ⅲ)ion/polyvinyl alcohol(CNC/Fe^(3+)/PVA)composite.The resultant composite films possessed robust mechanical performances,outstanding conductivity,and distinguished breathability(3.03 kg/(m^(2)·d)),which benefited from the multiple interactions of weak hydrogen bonds and Fe^(3+) chelation and synergistic effects among CNC,polyaniline(PANI),and PVA.Surprisingly,the film could be assembled as a multifunctional sensor to actively monitor real-time physical and infection related signals such as temperature,moisture,pH,NH3,and human movements even at sweat states.More importantly,this multifunctional device could act as a self-driven therapist to eliminate bacterial by the release of Fe^(3+),which was driven by the damage of metal coordination Fe-O bonds due to the high temperature caused by infection at wound sites.Thus,the composite films had potential versatile applications in electronic skins,smart wound dressings,human-machine interactions,and self-driven anti-infection therapy.

L.S.gratefully acknowledges the financial support from the Engineering and Physical Sciences Research Council(Nos.EP/L022559/1,EP/L022559/2,EP/V050311/1,and EP/W004399/1);Royal Society(Nos.RG130230 and IE161214);H2020 Marie Skłodowska-Curie Actions(No.790666);J.S.Z.was supported by a PhD Studentship provided by Queen Mary University of London and China Scholarship Council(CSC).

Advanced energy and sensor devices with novel applications(e.g.,mobile equipment,electric vehicles,and medical-healthcare systems)are one of the important foundations of modern intelligent life.However,there are still some scientific issues that seriously hinder the further development of devices,including unsustainability,high material cost,complex fabrication process,safety issues,and unsatisfactory performance.Nanocellulose has aroused tremendous attention in recent decades,because of its abundant resources,renewability,degradability,low-cost,and unique physical/chemical properties.These merits make nanocellulose as matrix materials to fabricate advanced functional composites for use in energy-related fields extremely competitive.Here,we comprehensively discuss the recent progress of nanocellulose for emerging energy storage/harvesting and sensor applications.The preparation methodologies of nanocellulose combined with conductive materials are firstly highlighted,including carbon materials,conductive polymers,metal/metal oxide nanoparticles,metal-organic frameworks(MOFs),and covalent organic frameworks(COFs).We then focus on the nanocellulose-based advanced materials for the application in the areas of supercapacitors,lithium-ion batteries,solar cells,triboelectric nanogenerators,moisture-enabled electric generators,and sensors.Lastly,the future research directions of nanocellulose-based functional materials in energy-related devices are presented.