About

Enrique Gomez is an Associate Dean for Equity & Inclusion and a Professor of Chemical Engineering at Penn State University. His affiliation includes the Engineering Dean's Office, the Chemical Engineering Department, and the Center for Engineering Outreach and Inclusion. His research focuses on connecting the chemistry, structure, and macroscopic properties of complex soft matter, including polymers, organic electronics, organic solar cells, and electron microscopy of soft materials. Gomez's educational background includes a BS in Chemical Engineering from the University of Florida and a Ph.D. in Chemical Engineering from the University of California, Berkeley. His scholarly contributions encompass a wide array of publications in areas such as energy and environment, materials science, and advanced functional materials, emphasizing the development and understanding of materials for energy, environmental, and biomedical applications.

Research topics

• Organic chemistry
• Chemistry
• Materials science
• Composite material
• Chemical engineering
• Polymer chemistry
• Nanotechnology
• Engineering
• Biochemistry
• Combinatorial chemistry
• Optoelectronics

Selected publications

• Cryogenic transmission electron microscopy reveals assembly and nanostructure of PEDOT:PSS

  Nature Communications · 2026-02-10

  articleOpen accessSenior author

  Soft and conducting organic materials are ideal candidates for stretchable bioelectronics and wearable devices. Despite recent advances, our understanding of conducting polymer nanostructures and how they arise remains incomplete, given the limited high-resolution studies and molecular-level descriptions of these systems. Here, we employ cryogenic transmission electron microscopy (cryo-EM) to investigate the evolution of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) morphology in solution and the resulting solid state structure in the presence of ionic and molecular additives. Our results reveal the formation of heterostructural elongated fibers consisting of PEDOT:PSS micelles in solution. Cryo-EM further reveals that additives increase the number of fibrils, in addition to inducing the formation of crystalline domains. We observe that fibril and crystalline phases in solutions act as a template for the growth of these nanostructures in the solid state. Furthermore, exploiting cryo-EM reveals the role of solid-liquid interactions in PEDOT:PSS through the imaging of PEDOT:PSS nanostructures after the hydration of thin films. Hydration leads to the swelling of heterostructural fibers while reducing the crystalline domain size. Such behavior explains the mechanical robustness of PEDOT:PSS thin films processed with various additives as well as the high electrical conductivity of PEDOT:PSS in applications such as organic electorchemical transistors. Soft and conducting organic materials are promising for electronic devices, though their nanostructures are not fully understood, due to the lack of high resolution real spacing imaging of these complex systems. Here the authors use cryogenic transmission electron microscopy methods to investigate the morphology of PEDOT:PSS in the presence of additives and upon hydration.

  PublisherOA PDFDOI

• Solution-state nanoconfined aggregation and microstructure evolution in blends of conjugated polymers and elastomers

  Proceedings of the National Academy of Sciences · 2026-04-24

  articleOpen accessCorresponding

  Emerging wearable health monitoring technologies require conformable and stretchable devices. Polymer semiconductors composed of π-conjugated polymer aggregates in an elastomeric matrix are remarkable in their ability to provide both high stretchability and enhanced charge transport. Understanding their film formation process is critical in improving charge transport, imparting added functionalities, and advancing large-scale production of high-performing polymer electronic devices. Here, using a poly-thieno[3,2-b]thiophene-diketopyrrolopyrrole (DPPTT): polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) blend as a model system, electron tomography of the blend reveals the presence of bundles of conjugated polymer nanofibers spanning the thickness of the films. High-resolution cryogenic electron microscopy (cryo-EM) of solution and thin films reveals that the nanoconfined DPPTT nanofibers in blends are composed of the aligned DPPTT 1D aggregates present in solution. In contrast, neat DPPTT solutions and thin films contain irregular crystalline domains with random orientations. In situ grazing incidence wide-angle X-ray scattering (GIWAXS) studies reveal that DPPTT crystallization commences earlier in blends compared to neat films. Combining observations from both in situ ultraviolet-visible spectroscopy, in situ GIWAXS and cryo-EM reveal that 1D aggregates in blend solution bundle and align into interconnected larger fibers that are nanoconfined in the SEBS matrix. This morphology is desirable for efficient charge transport and good mechanical strength. In contrast, neat DPPTT films contain randomly oriented smaller aggregates with an increased fraction of disordered domains. Overall, our work provides critical insights on the impact of solution composition and processing conditions on thin film morphology for achieving multifunctional high-performing electronic polymer composites.

  PublisherDOI

• Empirical evidence that glucan-interacting amino acid side chains within the transmembrane channel collectively facilitate cellulose synthase function

  Plant Molecular Biology · 2025-07-09 · 1 citations

  articleOpen access

  The fundamental mechanism of cellulose synthesis is widely conserved across Kingdoms and depends on cellulose synthases, which are processive, dual-function, family 2 glycosyltransferases (GT-2). These enzymes polymerize glucose on the cytoplasmic side of the plasma membrane and export the glucan chain to the cell surface through an integral transmembrane (TM) channel. Structural studies of active plant cellulose synthases (CESAs) have revealed interactions between the nascent glucan chain and the side chains of polar, charged, and aromatic amino acid residues that line the TM channel. However, the functional consequences of modifying these side chains have not been tested in vivo in CESAs or other processive GT-2s. To test this, we used an established in vivo assay based on genetic complementation of CESA5 in the moss, Physcomitrium patens. For accurate prediction of glucan-interacting amino acid residues, we generated a complete homotrimeric molecular model of PpCESA5 using a combination of homology and de novo modeling. All-atom molecular dynamics-based analyses of contact metrics and interaction energy identified 23 amino acid residues with high propensity to interact with the nascent glucan chain within the TM channel or on the apoplastic surface of PpCESA5. Mutating any one of 18 of these amino acid residues to alanine, thereby removing their side chains, abolished or impaired CESA function, with the strongest effects observed upon the loss of charged amino acid side chains. This provides direct evidence to support the hypothesis that multiple amino acid residues collectively maintain a smooth energy landscape within the TM channel to facilitate glucan translocation.

  PublisherDOI

• GRATEv2: computational tools for real-time analysis of high-throughput high-resolution TEM (HRTEM) images of conjugated polymers

  Materials Advances · 2025-01-01 · 2 citations

  articleOpen access

  Gratev2 enables near-real time HRTEM analysis: a graph-based pipeline extracts d-spacing, orientation, and shape metrics; Bayesian optimization auto-tunes parameters; a Wasserstein-distance signals when data collection is sufficient.

  PublisherOA PDFDOI

• Deciphering the Structure of PM6-Type Conjugated Polymer Aggregates in Solution and Film

  Chemistry of Materials · 2025-09-29 · 2 citations

  articleOpen access

  PDB and ITP files of PM6 periodic crystals for GROMACS.

  PublisherOA PDFDOI

• Correction: Semitransparent organic and perovskite photovoltaics for agrivoltaic applications

  Energy Advances · 2025-12-04

  articleOpen access

  Correction for ‘Semitransparent organic and perovskite photovoltaics for agrivoltaic applications’ by Souk Y. Kim et al. , Energy Adv. , 2025, 4 , 37–54, https://doi.org/10.1039/D4YA00492B.

  PublisherOA PDFDOI

• Interface engineering and integration of ceramic-polymer composites via cold sintering process

  Composites Part B Engineering · 2025-08-21 · 1 citations

  articleCorresponding
  PublisherDOI

• Co‐continuous composites from cold sintering

  Journal of the American Ceramic Society · 2025-06-03 · 4 citations

  articleCorresponding

  Abstract Cold sintering enables the fabrication of ceramic matrix‐polymer composites through low temperature densification by employing a transient solvent under moderate pressure to drive diffusional processes. This innovative processing allows the integration of seemingly incompatible components in a single step to provide new possibilities for tailored multifunctional composites. However, the microstructure of these cold‐sintered composites is controlled by a complex interplay between solubility, evaporation, plastic flow and compaction of the inorganic particles. Pressure solution creep process densifies the inorganic particulates through the dissolution, transport and precipitation at the interfaces of the particulates under applied stresses and slightly elevated temperatures. Through selection of ceramic (gypsum and MgO) and polymer (polypropylene and polymethyl methacrylate) materials that differ in densification mechanisms, new insights are gleaned about how material selection impacts the morphology and mechanical behavior of cold‐sintered composites. Cold sintering of gypsum leads to a well‐densified ceramic, while rapid hydration of MgO leads to minimal densification of the inorganic phase. This difference in ceramic densification affected characteristics of the composites, including the polymer distribution, phase connectivity, and mechanical performance. The high compaction of gypsum during cold sintering facilitated polymer infiltration between particles to form co‐continuous phases on cold sintering. In contrast, the limited densification of MgO did not promote flow of polymer and produced isolated polymer domains that led to poor mechanical performance in the cold sintered composites. Although the cold sintering temperature impacts the rheology of the polymer phase to alter the infiltration of the plastic between the inorganic phase during processing, the primary factor dictating the formation of co‐continuous phases and corresponding good mechanical performance is signficant densification of the ceramic during cold sintering. The processing temperature and material interactions between the polymer and inorganic phases also impact the morphology of cold sintered ceramic‐polymer composites. The combination of materials selection and cold sintering processing parameters provide routes to control morphology for engineering composites with cold sintering with a key heuristic identified here that the inclusion of the polymer cannot overcome poor sintering of the ceramic and densification (compaction) during cold sintering appears to drive the flow and developed connectivity of the polymer phase.

  PublisherDOI

• A Novel Strategy for Desalinating Highly Concentrated Seawater Employs Dilute Regeneration Solutions within a Membrane Capacitive Deionization System, Integrating Nanopatterned Membranes and Prussian Blue Analog-Infiltrated Electrodes

  ECS Meeting Abstracts · 2025-11-24

  article

  While Earth’s oceans contain about 97% of its water, their high salinity makes them unsuitable for human consumption [1]. In regions where freshwater is limited or unpredictable, seawater desalination can provide a substantial and dependable supply. Existing desalination technologies – reverse osmosis, thermal distillation, and electrodialysis – are effective but energy-intensive, relying on high pressure, thermal input, or electricity. Membrane capacitive deionization (MCDI) is a promising alternative due to its cost-effectiveness, energy efficiency, and environmentally friendly operation. MCDI uses electrochemical adsorption and desorption of salt ions for separation. It is modular, electrified, and does not require high-pressure piping or generate significant acoustic, thermal, or electromagnetic signatures. Flow-by MCDI, a commercialized design, removes ions using electrical energy and consists of two porous electrodes covered by ion-exchange membranes [2]. However, the salt adsorption capacity of carbon electrodes is limited to ~40 mg/g, making them ineffective for seawater desalination [3]. Achieving full electrode regeneration is essential to maximize salt removal. This work introduces an operational strategy using dilute NaCl regeneration solutions (0–5 g/L) to treat 35 g/L NaCl and a mixture of 30 g/L NaCl with 5 g/L MgSO₄. Additionally, surface patterning is explored as a method to enhance membrane performance by increasing the interfacial area and salt flux [4]. Patterned membranes have been shown to improve local hydrodynamics, enhance concentration polarization via secondary flows, and reduce boundary layer thickness and osmotic pressure. Poly(phenylene) alkylene ion-exchange membranes were fabricated with nanopatterns—hexagonal, double ring, octagonal, and rectangular—ranging from 100 to 300 nm using electron beam lithography. Silicon wafers were spin-coated with Zep 520A121 resist and anisole (1:1), baked at 180°C, and exposed using a RAITH EBPG 5200 system (150 nA, 600 µm aperture, 180 µC/cm²). Patterns were developed in n-Amyl acetate and 2-propanol, then dried. PDMS molds were formed by mixing Sylgard 184 elastomer and curing agent (10:1), degassing, pouring onto the patterned wafer, and curing at 65°C for 4 hours. Ionomers were drop-cast onto the molds. To further enhance performance, Prussian blue analogues (PBAs)—redox-active materials with open framework structures—were used as electrode modifiers to improve salt adsorption and charge redistribution [5][6]. A nickel PBA (NaNi[Fe(CN)₆]·nH₂O) was mixed with PVDF and conductive carbon (8:1:1) in N-methyl-2-pyrrolidone and coated on activated carbon cloth electrodes. Initial results show strong deionization across regeneration concentrations (0–5000 ppm NaCl), with minor ion accumulation at 5000 ppm. Compared to flat membranes, hexagonal nanopatterned membranes showed the greatest surface area enhancement, a ~500 mV reduction in cell voltage during chronopotentiometry, a 45 Ω·cm² decrease in area-specific resistance, and an 18.71 Ω·cm² reduction in capacitance during impedance spectroscopy. These findings show that combining dilute regeneration strategies, nanopatterned membranes, and PBA-modified electrodes enables MCDI to effectively manage higher salinity feeds, expanding its potential for seawater desalination. References Saline water and salinity. (n.d.). USGS. Retrieved March 25, 2025, from https://www.usgs.gov/special-topics/water-science-school/science/saline-water-and-salini Palakkal, V. M., Rubio, J. E., Lin, Y. J., & Arges, C. G. (2018). Low-resistant ion-exchange membranes for energy efficient membrane capacitive deionization. ACS Sustainable Chemistry & Engineering , 6 (11), 13778-13786. Tang, K., Kim, Y. H., Chang, J., Mayes, R. T., Gabitto, J., Yiacoumi, S., & Tsouris, C. (2019). Seawater desalination by over-potential membrane capacitive deionization: Opportunities and hurdles. Chemical engineering journal , 357 , 103-111. Hasan, M., Shrimant, B., Waters, C. B., Gorski, C. A., & Arges, C. G. (2024). Reducing Ohmic Resistances in Membrane Capacitive Deionization Using Micropatterned Ion‐Exchange Membranes, Ionomer Infiltrated Electrodes, and Ionomer‐Coated Nylon Meshes. Small Structures , 5 (9), 2400090. Zhang, X., & Dutta, J. (2021). X-Fe (X= Mn, Co, Cu) Prussian blue analogue-modified carbon cloth electrodes for capacitive deionization. ACS Applied Energy Materials , 4 (8), 8275-8284. Pothanamkandathil, V., Boualavong, J., & Gorski, C. A. (2023). Open-circuit potential drift in intercalation electrodes: role of charge redistribution in a prussian blue analog. Journal of The Electrochemical Society , 170 (11), 110503. Figure 1

  PublisherDOI

• Shear‐Induced Nematic Alignment in Polysulfone Melts

  Advanced Functional Materials · 2025-06-01 · 1 citations

  articleOpen access

  Abstract Polymer melt processing often requires conditions of temperature and shear that create flow‐induced structures that impact the properties of the resulting material. Such an effect is connected to chain stretching, often leading to shear‐induced nematic alignment of at least the longest chains, reported for rod‐like polymers but also polyolefins. A polysulfone melt is shown here to undergo such nematic alignment, as can be predicted from its chain stiffness. Its convenient chain linearity, verified by very good agreement of the linear viscoelastic data with a tube model (BoB) for entangled polymer melts, and its inability to crystallize make it suitable for exploring the temperature dependence of the nematic alignment, monitored by both rheology and birefringence. The critical shear rate for nematic alignment at various temperatures is determined and contrasted with that expected from the Rouse time of the longest chains, often considered as the control parameter. Although the onset shear rate for nematic alignment is shown to follow the same temperature dependence as the chain relaxation times, suggesting that chain stretching is the underlying mechanism, the critical shear rate is much smaller than expected. This anomalous behavior of polysulfone is discussed in relation with possible π‐stacking interactions stabilizing the nematic domains.

  PublisherOA PDFDOI

Recent grants

• Transmission electron microscopy of conjugated polymers using energy-filtering and phase contrast enhancement

  NSF · $417k · 2016–2019

• DMREF: Tuning Liquid Crystallinity in Conjugated Polymers to Simultaneously Enhance Charge Transport and Control Mechanical Properties

  NSF · $1.8M · 2019–2023

• Doping and Morphological Control at the Semiconductor-Electrode Interface in Organic Solar Cells

  NSF · $307k · 2011–2014

• CAREER: Mechanobiology of Mesenchymal-Epithelial Transition

  NSF · $532k · 2018–2024

• Pushing the limits of transmission electron microscopy of polymers

  NSF · $854k · 2019–2025

Frequent coauthors

• Nitash P. Balsara

  Lawrence Berkeley National Laboratory

  89 shared

• Esther W. Gomez

  Pennsylvania State University

  52 shared

• Youngmin Lee

  Oral Roberts University

  45 shared

• Alexander Hexemer

  Lawrence Berkeley National Laboratory

  30 shared

• Scott T. Milner

  National Society of Professional Engineers

  30 shared

• Kiarash Vakhshouri

  Pennsylvania State University

  27 shared

• Timothy J. Rappl

  University of California, Berkeley

  26 shared

• Andrew M. Minor

  University of California, Berkeley

  26 shared

Labs

• Chemical EngineeringPI

Education

• Doctor of Philosphy

  The University of California Berkeley

  2007

• Bachelor of Science

  The University of Florida

  2002

Awards & honors

• Outstanding Engineering Alumni Award
• Early Career Alumni Recognition Award
• Alumni Achievement Award
• Alumni Fellow Award