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Abstract 4D printing is the 3D printing of objects that change chemically or physically in response to an external stimulus over time. Photothermally responsive shape memory materials are attractive for their ability to undergo remote activation. While photothermal methods using gold nanorods (AuNRs) are used for shape recovery, 3D patterning of these materials into objects with complex geometries using degradable materials is not addressed. Here, the fabrication of 3D printed shape memory bioplastics with photo‐activated shape recovery is reported. Protein‐based nanocomposites based on bovine serum albumin (BSA), poly (ethylene glycol) diacrylate (PEGDA), and AuNRs are developed for vat photopolymerization. These 3D printed bioplastics are mechanically deformed under high loads, and the proteins served as mechano‐active elements that unfolded in an energy‐dissipating mechanism that prevented fracture of the thermoset. The bioplastic object maintained its metastable shape‐programmed state under ambient conditions. Subsequently, up to 99% shape recovery is achieved within 1 min of irradiation with near‐infrared (NIR) light. Mechanical characterization and small angle X‐ray scattering (SAXS) analysis suggest that the proteins mechanically unfold during the shape programming step and may refold during shape recovery. These composites are promising materials for the fabrication of biodegradable shape‐morphing devices for robotics and medicine. 

Abstract The sustainable synthesis of macromolecules with control over sequence and molar mass remains a challenge in polymer chemistry. By coupling mechanochemistry and electron‐transfer processes (i.e., mechanoredox catalysis), an energy‐conscious controlled radical polymerization methodology is realized. This work explores an efficient mechanoredox reversible addition‐fragmentation chain transfer (RAFT) polymerization process using mechanical stimuli by implementing piezoelectric barium titanate and a diaryliodonium initiator with minimal solvent usage. This mechanoredox RAFT process demonstrates exquisite control over poly(meth)acrylate dispersity and chain length while also showcasing an alternative to the solution‐state synthesis of semifluorinated polymers that typically utilize exotic solvents and/or reagents. This chemistry will find utility in the sustainable development of materials across the energy, biomedical, and engineering communities. 

The nano- and micron scale morphology of poly(3-hexylthiophene) (P3HT) and polystyrene-block-polyisoprene-block-polystyrene (PS–PI–PS) elastomeric blends is investigated through the use of ultra-small and small angle X-ray and neutron scattering (USAXS, SAXS, SANS). It is demonstrated that loading P3HT into elastomer matrices is possible with little distortion of the elastomeric structure up to a loading of ∼5 wt%. Increased loadings of conjugated polymer is found to significantly distort the matrix structure. Changes in processing conditions are also found to affect the blend morphology with especially strong dependence on processing temperature. Processing temperatures above the glass transition temperature (Tg) of polystyrene and the melting temperature (Tm) of the conjugated polymer additive (P3HT) creates significantly more organized mesophase domains. P3HT blends with PS–PI–PS can also be flow-aligned through processing, which results in an anisotropic structure that could be useful for the generation of anisotropic properties (e.g. conductivity). Moreover, the extent of flow alignment is significantly affected by the P3HT loading in the PS–PI–PS matrix. The work adds insight to the morphological understanding of a complex P3HT and PS–PI–PS polymer blend as conjugated polymer is added to the system. We also provide studies isolating the effect of processing changes aiding in the understanding of the structural changes in this elastomeric conjugated polymer blend. 

Globally, traumatic injury is a leading cause of suffering and death. The ability to curtail damage and ensure survival after major injury requires a time‐sensitive response balancing organ perfusion, blood loss, and portability, underscoring the need for novel therapies for the prehospital environment. Currently, there are few options available for damage control resuscitation (DCR) of trauma victims. We hypothesize that synthetic polymers, which are tunable, portable, and stable under austere conditions, can be developed as effective injectable therapies for trauma medicine. In this work, we design injectable polymers for use as low volume resuscitants (LVRs). Using RAFT polymerization, we evaluate the effect of polymer size, architecture, and chemical composition upon both blood coagulation and resuscitation in a rat hemorrhagic shock model. Our therapy is evaluated against a clinically used colloid resuscitant, Hextend. We demonstrate that a radiant star poly(glycerol monomethacrylate) polymer did not interfere with coagulation while successfully correcting metabolic deficit and resuscitating animals from hemorrhagic shock to the desired mean arterial pressure range for DCR – correcting a 60% total blood volume (TBV) loss when given at only 10% TBV. This highly portable and non‐coagulopathic resuscitant has profound potential for application in trauma medicine. 

In recent years, nanocellulose has emerged as a sustainable and environmentally friendly alternative to traditional petroleum-derived structural polymers. Sourced either from plants, algae, or bacteria, nanocellulose can be processed into colloid, gel, film and fiber forms. However, the required fundamental understanding of process parameters that govern the morphology and structure–property relationships of nanocellulose systems, from colloidal suspensions to bulk materials, has not been developed and generalized for all forms of cellulose. This further hinders the more widespread adoption of this biopolymer in applications. Our study investigates the dispersion of cellulose nanofibers (CNFs) produced by a bacterial–yeast co-culture, in solvents, highlighting the role of thermodynamic interactions in influencing their colloidal behavior. By adjusting Hansen solubility parameters, we controlled the thermodynamic relationship between CNFs and solvents across various concentrations, studying the dilute to semi-dilute regimes. Rheological measurements revealed that the threshold at which a concentration-based regime transition occurs is distinctly solvent-dependent. Complementing rheological analysis with small angle X-ray scattering and zeta potential measurements, our findings reveal that enhancing CNF–solvent interactions increases excluded volume in the dilute regime, emphasizing the importance of the balance between fiber–fiber and fiber–solvent interactions. Moreover, we investigated the transition from colloidal to solid state by creating films from dispersions with varying interaction parameters in semi-dilute regimes. Through mechanical testing and scanning electron microscopy imaging of the fracture surfaces, we highlight the significance of electrokinetic effects in such transitions, as dispersions with higher electrokinetic stabilization gave rise to stronger and tougher films despite having less favorable thermodynamic interaction parameters. Our work provides insights into the thermodynamic and electrokinetic interplay that governs bacterial CNF dispersion, offering a foundation for future application and a deeper understanding of nanocellulose's colloidal and structure-property relationships. 

We present an autonomous data-driven framework that iteratively explores the experimental design space of silver nanoparticle synthesis to obtain control over the formation of a desired morphology and size. The objective of the method is to identify design rules such as the effects of the design variables on the structure of the nanoparticle. The framework balances multimodal characterization methods (i.e. UV-vis spectroscopy, SAXS, TEM), taking into account the cost of performing a measurement and the quality of information gained. By integrating with an AI agent, we identify important design variables in the synthesis of small colloidally stable plate-like silver particles and outline how each variable affects plate thickness, radius, polydispersity, and relative concentration. Our findings are consistent with the literature, demonstrating that the framework could be further applied to new systems that have not been well characterized and understood. The framework is generalizable and allows tangible knowledge extraction from the high-throughput experimental runs while still considering inherent stochasticity. 

Thin metal particles with two-dimensional symmetry are attractive for multiple ap- plications, but are difficult to synthesize in a reproducible manner. Although molecules that selectively adsorb to facets have been used to control nanoparticle shape, there is still limited research into the temporal control of growth processes to control these structural outcomes. Moreover, much of the current research into the growth of thin two-dimensional particles lacks mechanistic details. In this work, we study why the substitution of isoleucine for methionine in a gold binding peptide (Z2, RMRMKMK) results in an increase in gold nanoparticle anisotropy. Nanoplatelet growth in the pres- ence of Z2M246I (RIRIKIK) is characterized using in situ small-angle X-ray scattering (SAXS) and UV-Vis spectroscopy. Fitting time-resolved SAXS profiles reveals that 10 nm thick particles with two-dimensional symmetry are formed within the first few min- utes of the reaction. Next, through a combination of electron diffraction and molecular dynamics simulations, we show that substitution of methionine for isoluecine increases the (111) facet selectivity in Z2M246I, and conclude that this is key to the growth of nanoplatelets. However, the potential application of nanoplatelets formed using Z2M246I is limited due to their uncontrolled lateral growth, aggregation, and rapid sedimentation. Therefore, we use a liquid handling robot to perform temporally con- trolled synthesis and dynamic intervention through the addition of Z2 to nanoplatelets growing in the presence of Z2M246I at different times. UV-Vis spectroscopy dynamic light scattering, and electron microscopy show that dynamic intervention results in control over the mean-size and stability of plate-like particles. Finally, we use in situ UV-Vis spectroscopy to study plate-like particle growth at different times of interven- tion. Our results demonstrate that both the selectivity and magnitude of binding free energy towards lattices is important for controlling nanoparticle growth pathways. 

We present a complete open-hardware and software materials acceleration platform (MAP) for sonochemical synthesis of nanocrystals using a versatile tool-changing platform (Jubilee) configured for automated ultrasound application, a liquid-handling robot (Opentrons OT2) and a well-plate spectrometer. An automated high-throughput protocol was developed demonstrating the synthesis of CdSe nanocrystals using sonochemistry and different combinations of sample conditions, including precursor and ligand compositions and concentrations. Cavitation caused by ultrasound fields causes local and transient increases in temperature and pressure sufficient to drive the decomposition of organometallic precursors to drive the chemical reaction leading to nanocrystal formation. A total of 625 unique sample conditions were prepared and analyzed in triplicate with an individual sample volume of as little as 0.5 mL, which drastically reduced chemical waste and experimental times. The rapid onset of cavitation and quick dissipation of energy result in fast nucleation with little nanocrystal growth leading to the formation of small nanocrystals or magic-size clusters (MSCs) depending on composition. Using the effective mass approximation, the calculated QD diameters obtained under all our experimental conditions ranged between 1.3 and 2.1 nm, which was also validated with small angle X-ray scattering (SAXS). Polydispersity, QD shape and optical properties largely varied depending on the concentration of ligands present in solution. Statistical analysis of the spectroscopic data corroborates the qualitative relationships observed from the optical characterization of the samples with the model-agnostic SHAP analysis. The complete workflow relies on relatively low-cost and open-source systems. Automation and the reduced volumes also allow for cost-efficient experimentation, increasing the accessibility of this MAP. The high-throughput capabilities of the automated sonication platform, the extensible nature of the Jubilee system, and the modular nature of the protocol, make the workflow adaptable to a variety of future studies, including other nanocrystal design spaces, emulsification processes, and nanoparticle re-dispersion or exfoliation.