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Short-wave infrared (SWIR) imaging has been extensively used in defense applications but remains underutilized in the study of soft materials and the broader consumer products industry. Water molecules absorb around ~1450 nm, making moisture-rich objects appear black, whereas surfactants and other common molecules in consumer products do not absorb and provide good contrast. This experimental study showcases the varied capabilities of SWIR imaging in tracking water transport in soft material systems by analyzing dissolution dynamics, tracking phase transitions (when combined with cross-polarized optical imaging), and monitoring drying kinetics in surfactant and polymer solutions. The dynamic phase evolution to equilibria of a binary aqueous solution of a non-ionic surfactant hexaethylene glycol monododecyl ether (C12E6) is presented. The influence of confined hydration in dynamic diffusive interfacial transport (D-DIT) capillaries was investigated by tracking the micellar to hexagonal phase transition concentration (C*). The effects of varying concentrations of an industrially relevant additive - monovalent common salt (NaCl), on the radial (2D) dissolution of lamellar-structured concentrated sodium lauryl ether sulfate (70 wt.% SLE1S) pastes was studied. An equation was developed to estimate the radial dissolution coefficients based on total dissolution time, and surfactant concentrations in the sample and solvent. Water loss was investigated by tracking the drying of aqueous poly(vinyl) alcohol films. In-situ monitoring of drying kinetics is used to draw correlations between the solution viscosity and drying time. SWIR imaging has already revealed previously inaccessible insights into surfactant hydration and holds the potential to become a turnkey method in tracking water transport - enabling better quality control and product stability analysis. 

We report a transformative epoxy system with a microalgae-derived bio-binder from hydrothermal liquefaction processing (HTL). The obtained bio-binder not only served as a curing agent for conventional epoxy resin (e.g., EPON 862), but also acted as a modifying agent to enhance the thermal and mechanical properties of the conventional epoxy resin. This game-changing epoxy/bio-binder system outperformed the conventional epoxy/hardener system in thermal stability and mechanical properties. Compared to the commercial EPON 862/EPIKURE W epoxy product, our epoxy/bio-binder system (35 wt.% bio-binder addition with respect to the epoxy) increased the temperature of 60% weight loss from 394 °C to 428 °C and the temperature of maximum decomposition rate from 382 °C to 413 °C, while the tensile, flexural, and impact performance of the cured epoxy improved in all cases by up to 64%. Our research could significantly impact the USD 38.2 billion global market of the epoxy-related industry by not only providing better thermal and mechanical performance of epoxy-based composite materials, but also simultaneously reducing the carbon footprint from the epoxy industry and relieving waste epoxy pollution. 

We report a transformative epoxy system with a microalgae-derived bio-binder from hydrothermal liquefaction processing (HTL). The obtained bio-binder not only served as a curing agent for conventional epoxy resin (e.g., EPON 862), but also acted as a modifying agent to enhance the thermal and mechanical properties of the conventional epoxy resin. This game-changing epoxy/bio-binder system outperformed the conventional epoxy/hardener system in thermal stability and mechanical properties. Compared to the commercial EPON 862/EPIKURE W epoxy product, our epoxy/bio-binder system (35 wt.% bio-binder addition with respect to the epoxy) increased the temperature of 60% weight loss from 394 °C to 428 °C and the temperature of maximum decomposition rate from 382 °C to 413 °C, while the tensile, flexural, and impact performance of the cured epoxy improved in all cases by up to 64%. Our research could significantly impact the USD 38.2 billion global market of the epoxy-related industry by not only providing better thermal and mechanical performance of epoxy-based composite materials, but also simultaneously reducing the carbon footprint from the epoxy industry and relieving waste epoxy pollution. 

Abstract Traditionally, resins and hardeners are produced by chemical and petroleum industries. These industries make use of non-renewable energy resources like fossil fuels for manufacturing the resins and curing agents. In addition, most of the conventional curing agents used in epoxy resins are highly noxious in nature causing skin allergies and asthma. The green epoxy resin is capable of reducing these toxic effects but have few shortcomings including its cost and the mechanical performance of cured epoxy resin. On the other hand, there is a dearth of investigation in the evolution of green or sustainable curing agents known as bio-binders. This paper presents the prediction of mechanical properties by replacement of conventional curing agent with amine derivative synthesized from bio-degradable resource in a thermoset epoxy resin system. The properties are predicted by molecular dynamics simulations using Materials Studio Software. Graphical Abstract 

Thermoset polymer composites, known for their outstanding thermal, mechanical, and chemical properties, have found applications in diverse fields, including aerospace and automotive industries. These polymers, once cured, cannot be recycled, making the end-of-life management of these composites very difficult and posing an environmental challenge. Conventional recycling methods are unsuitable for thermosets, forcing their accumulation in landfills and raising environmental concerns. One possible solution to overcome this concern is to use resins or curing agents, or both, made from biodegradable materials. This study explores the fabrication and characterization of polymer composites using a commercially available green curing agent made from biomass. The composite laminates were fabricated using HVARTM (Heated Vacuum Assisted Resin Transfer Molding) process. In this process, heat pads are used to increase the temperature of both the epoxy resin and the plain weave carbon fiber laminate to a desired temperature, providing ease of flow to the resin. Small coupons were cut from the laminate using a water jet machine to study the flexural behavior of the composite in accordance with ASTM testing standards and compared with composite coupons fabricated using conventional epoxy resin. 

Structure-property-processing relationships for model lamellar structured 70 wt.% SLEnS solutions were developed with a combination of rheometry, cross-polarized optical microscopy, calorimetry, small angle X-ray scattering, and rheo-ultrasonic speckle velocimetry. Additives were utilized to maintain high surfactant activity, reduce bulk viscosity and simplify processing. While the bulk flow behavior of neat SLEnS solutions was similar, the effect of some additives was sensitive to the degree of ethoxylation. Linear-chain alcohols (C2-C5) partitioned into inter-bilayer water layers, dehydrating surfactant headgroups and inducing lamellar-to-micellar transitions. Short-chain polyols formed higher-viscosity hexagonal and mixed phases at room temperature through hydrogen bonding with surfactant headgroups. Heating beyond the upper temperature limit weakened these interactions, resulting in low-viscosity solutions. Within the lamellar phase, common salt promoted shear-induced crystallization above the equilibrium temperature range. Propylene glycol suppressed shear-induced crystallization and promoted wall-slip under shear, forming lubrication layers near the wall. These strategies offer practical levers to tune rheology and microstructure of concentrated surfactant systems, with the datasets developed providing a foundation for future modeling. Outcomes from this study inform the sustainable design and efficient processing of concentrated surfactant-based products. 

Current methods to develop surfactant phase diagrams are time-intensive and fail to capture the kinetics of phase evolution. Here, the design and performance of a quantitative swelling technique to study the dynamic phase behavior of surfactants are described. The instrument combines cross-polarized optical and short-wave infrared imaging to enable high-resolution, high-throughput, and in situ identification of phases and water compositions. Data across the entire composition spectrum for the dynamics and phase evolution of a binary aqueous non-ionic surfactant solution at two isotherms are presented. This instrument provides pathways to develop non-equilibrium phase diagrams of surfactant systems—critical to predicting the outcomes of formulation and processing. It can be applied to study time-dependent material relationships across a diverse range of materials and processes, including the dissolution of surfactant droplets and the drying of aqueous polymer films.