Industrial decarbonization: A revolution ahead

Clean Technologies and Environmental Policy -     

Self-Healing and -Repair of Nanomechanical Damages in Lead Halide Perovskites

Recovery from damage in materials helps extend their useful lifetime and of devices that contain them. Given that the photodamages in HaP materials and based devices are shown to recover, the question arises if this also applies to mechanical damages, especially those that can occur at the nanometer scale, relevant also in view of efforts to develop flexible HaP-based devices. Here, this question is addressed by poking HaP single crystal surfaces with an atomic force microscope (AFM) tip under both ultra-high vacuum (UHV) and variably controlled ambient water vapor pressure conditions. Sequential in situ AFM scanning allowed real-time imaging of the morphological changes at the damaged sites. Using methylammonium (MA) and cesium (Cs) variants for A-site cations in lead bromide perovskites, the experiments show that nanomechanical damages on methylammonium lead bromide (MAPbBr₃) crystals heal an order of magnitude faster than Cs-based ones in UHV. However, surprisingly, under ≥40% RH conditions, cesium lead bromide (CsPbBr₃) shows MAPbBr₃-like fast healing kinetics. Direct evidence for ion solvation on CsPbBr₃ is presented, leading to the formation of a surface hydration layer. The results imply that moisture improves the ionic mobility of degradation components and leads to water-assisted improved healing, i.e., repair of nanomechanical damages in the HaPs.     

Tailoring the Surface Chemistry of PEDOT:PSS to Promote Supported Lipid Bilayer Formation

This communication reports on a versatile and substrate-agnostic method to tune the surface chemistry of conducting polymers with the aim of bridging the chemical mismatch between bioelectronic devices and biological systems. As a proof of concept, the surface of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is grafted with a short-chain oligoethylene glycol monolayer to favor the formation of cell-derived supported lipid bilayers (SLBs). This method is tuned to optimize the affinity between the supported lipid bilayer and the conducting polymer, leading to significant improvements in bilayer quality and therefore electronic readouts. To validate the impact of surface functionalization on the system's ability to transduce biological phenomena into quantifiable electronic signals, the activity of a virus commonly used as a surrogate for SARS-CoV-2 (mouse hepatitis virus) is monitored with and without surface treatment. The functionalized devices exhibit significant improvements in electronic output, stemming from the improved SLB quality, therefore strengthening the case for the use of such an approach in membrane-on-a-chip systems.     

Towards sustainable Cleaning-in-Place (CIP) in dairy processing: Exploring enzyme-based approaches to cleaning in the Cheese industry

Cleaning-in-place (CIP) is the most commonly used cleaning and sanitation system for processing lines, equipment, and storage facilities such as milk silos in the global dairy processing industry. CIP employs thermal treatments and nonbiodegradable chemicals (acids and alkalis), requiring appropriate neutralization before disposal, resulting in sustainability challenges. In addition, biofilms are a major source of contamination and spoilage in dairy industries, and it is believed that current chemical CIP protocols do not entirely destroy biofilms. Use of enzymes as effective agents for CIP and as a more sustainable alternative to chemicals and thermal treatments is gaining interest. Enzymes offer several advantages when used for CIP, such as reduced water usage (less rinsing), lower operating temperatures resulting in energy savings, shorter cleaning times, and lower costs for wastewater treatment. Additionally, they are typically derived from natural sources, are easy to neutralize, and do not produce hazardous waste products. However, even with such advantages, enzymes for CIP within the dairy processing industry remain focused mainly on membrane cleaning. Greater adoption of enzyme-based CIP for cheese industries is projected pending a greater knowledge relating to cost, control of the process (inactivation kinetics), reusability of enzyme solutions, and the potential for residual activity, including possible effects on the subsequent product batches. Such studies are essential for the cheese industry to move toward more energy-efficient and sustainable cleaning solutions.