@article{Hatch2017, author = {Hatch, Harold W. and Jiao, Sally and Mahynski, Nathan A. and Blanco, Marco A. and Shen, Vincent K.}, doi = {10.1063/1.5016165}, journal = {The Journal of Chemical Physics}, month = {dec}, pages = {231102}, title = {Communication: Predicting virial coefficients and alchemical transformations by extrapolating Mayer-sampling Monte Carlo simulations}, url = {https://oadoi.org/10.1063/1.5016165}, volume = {147}, year = {2017} } @article{Hatch2018, author = {Hatch, Harold W. and Mahynski, Nathan A. and Shen, Vincent K.}, doi = {10.6028/jres.123.004}, journal = {Journal of Research of the National Institute of Standards and Technology}, month = {mar}, title = {FEASST: Free Energy and Advanced Sampling Simulation Toolkit}, url = {https://doi.org/10.6028/jres.123.004}, volume = {123}, year = {2018} } @article{Hatch2018_2, author = {Hatch, Harold W. and Mahynski, Nathan A. and Murphy, Ryan P. and Blanco, Marco A. and Shen, Vincent K.}, doi = {10.1063/1.5040252}, journal = {AIP Advances}, month = {sep}, pages = {095210}, title = {Monte Carlo simulation of cylinders with short-range attractions}, url = {https://doi.org/10.1063/1.5040252}, volume = {8}, year = {2018} } @article{Mahynski2014, abstract = {Recent work [Mahynski et al., Nat. Commun., 2014, 5, 4472] has demonstrated that the addition of long linear homopolymers thermodynamically biases crystallizing hard-sphere colloids to produce the hexagonal close-packed (HCP) polymorph over the closely related face-centered cubic (FCC) structure when the polymers and colloids are purely repulsive. In this report, we investigate the effects of thermal interactions on each crystal polymorph to explore the possibility of stabilizing the FCC crystal structure over the HCP. We find that the HCP polymorph remains at least as stable as its FCC counterpart across the entire range of interactions we explored, where interactions were quantified by the reduced second virial coefficient, -1.50 < B < 1.01. This metric conveniently characterizes the crossover from entropically to energetically dominated systems at B ≈ 0. While the HCP relies on its octahedral void arrangement for enhanced stability when B > 0, its tetrahedral voids produce a similar effect when B < 0 (i.e. when energetics dominate). Starting from this, we derive a mean-field expression for the free energy of an infinitely-dilute polymer adsorbed in the crystal phase for nonzero B. Our results reveal that co-solute biasing of a single polymorph can still be observed in experimentally realizable scenarios when the colloids and polymers have attractive interactions, and provide a possible explanation for the experimental finding that pure FCC crystals are elusive in these binary mixtures.}, author = {Mahynski, Nathan A. and Kumar, Sanat K. and Panagiotopoulos, Athanassios Z.}, doi = {10.1039/c4sm02191f}, journal = {Soft Matter}, month = {nov}, pages = {280-289}, title = {Relative stability of the FCC and HCP polymorphs with interacting polymers}, url = {https://www.researchgate.net/profile/Nathan_Mahynski/publication/268873979_Relative_stability_of_the_FCC_and_HCP_polymorphs_with_interacting_polymers/links/560334f408ae460e2704c917.pdf}, volume = {11}, year = {2014} } @article{Mahynski2015, abstract = {Polymers dilutely adsorbed in colloidal crystals play an underappreciated role in determining the stability of the crystal phase. Recent work has shown that tailoring the size and shape of the adsorbing polymer can help tune the relative thermodynamic stability of the face-centered cubic (FCC) and hexagonal close-packed (HCP) polymorphs [N. A. Mahynski, A. Z. Panagiotopoulos, D. Meng, and S. K. Kumar, Nat. Commun. 5, 4472 (2014)]. This is a consequence of how different polymorphs uniquely distribute their interstitial voids. By engineering an adsorbent's morphology to be complementary to the interstices in a desired crystal form, other competing forms may be thermodynamically suppressed. Previous investigations into this effect focused solely on linear polymers, while here we investigate the effects of more complex polymer architectures, namely that of star polymers. We find that even small perturbations to an adsorbing polymer's architecture lead to significant, qualitative changes in the relative stability of close-packed colloidal crystal polymorphs. In contrast to the linear homopolymer case, the FCC phase may be re-stabilized over the HCP with sufficiently large star polymers, and as a result, solvent quality may be used as a polymorphic "switch" between the two forms. This suggests that star polymers can be engineered to stabilize certain crystal phases at will using experimentally accessible parameters such as temperature.}, author = {Mahynski, Nathan A. and Kumar, Sanat K. and Panagiotopoulos, Athanassios Z.}, doi = {10.1039/c5sm00631g}, journal = {Soft Matter}, month = {jan}, pages = {5146-5153}, title = {Tuning Polymer Architecture to Manipulate the Relative Stability of Different Colloid Crystal Morphologies}, url = {https://www.researchgate.net/profile/Nathan_Mahynski/publication/277335734_Tuning_Polymer_Architecture_to_Manipulate_the_Relative_Stability_of_Different_Colloid_Crystal_Morphologies/links/5575ed7a08ae7521586c28f1.pdf}, volume = {11}, year = {2015} } @article{Mahynski2015_2, author = {Mahynski, Nathan A. and Panagiotopoulos, Athanassios Z.}, doi = {10.1063/1.4908044}, journal = {The Journal of Chemical Physics}, month = {feb}, pages = {074901}, title = {Grafted nanoparticles as soft patchy colloids: Self-assembly versus phase separation}, url = {https://www.researchgate.net/profile/Nathan_Mahynski/publication/272415474_Grafted_nanoparticles_as_soft_patchy_colloids_Self-assembly_versus_phase_separation/links/54ebabca0cf2082851be5aec.pdf}, volume = {142}, year = {2015} } @article{Mahynski2015_3, abstract = {We study the effective interactions and phase behavior of star polymer–colloid mixtures through theory and Monte Carlo simulations. We extend previous theoretical approaches for calculating the effective star–colloid pair potential to take into account attractive contributions, which become significant at worsening solvent conditions. In order to assess the validity of our simulation and theory, we compute the effective interactions via virtual move parallel tempering Monte Carlo simulations using a microscopic bead-spring model for the star polymer and achieve excellent agreement. Finally, we perform grand canonical Monte Carlo simulations of the coarse-grained systems to study the effect of solvent quality on the phase behavior.}, author = {Mahynski, Nathan A. and Nikoubashman, Arash and Capone, Barbara and Panagiotopoulos, Athanassios Z. and Likos, Christos N.}, doi = {10.1063/1.4931410}, journal = {The Journal of Chemical Physics}, month = {sep}, pages = {243108}, title = {Coarse-graining and phase behavior of model star polymer–colloid mixtures in solvents of varying quality}, url = {https://www.researchgate.net/profile/Nathan_Mahynski/publication/282120640_Coarse-graining_and_phase_behavior_of_model_star_polymer-colloid_mixtures_in_solvents_of_varying_quality/links/560334b608ae08d4f17151ab.pdf}, volume = {143}, year = {2015} } @article{Mahynski2016, author = {Mahynski, Nathan A.}, doi = {10.13140/rg.2.1.4529.6407}, journal = {Molecular Physics}, month = {feb}, pages = {2586-2596}, title = {Entropic Control over Nanoscale Colloidal Crystals}, url = {https://www.researchgate.net/profile/Nathan_Mahynski/publication/296698708_Entropic_Control_over_Nanoscale_Colloidal_Crystals/links/56d8cef608aebe4638b93947.pdf}, volume = {114}, year = {2016} } @article{Mahynski2016_2, author = {Mahynski, Nathan A. and Rovigatti, Lorenzo and Likos, Christos N. and Panagiotopoulos, Athanassios Z.}, doi = {10.1021/acsnano.6b01854}, journal = {ACS Nano}, month = {apr}, pages = {5459-5467}, title = {Bottom-Up Colloidal Crystal Assembly with a Twist}, url = {http://doi.org/10.1021/acsnano.6b01854}, volume = {10}, year = {2016} } @article{Mahynski2016_3, author = {Mahynski, Nathan A. and Shen, Vincent K.}, doi = {10.1063/1.4966573}, journal = {The Journal of Chemical Physics}, month = {nov}, pages = {174709}, title = {Multicomponent adsorption in mesoporous flexible materials with flat-histogram Monte Carlo methods}, url = {http://europepmc.org/articles/pmc5206665?pdf=render}, volume = {145}, year = {2016} } @article{Mahynski2017, author = {Mahynski, Nathan A. and Zerze, Hasan and Hatch, Harold W. and Shen, Vincent K. and Mittal, Jeetain}, doi = {10.1039/c7sm01005b}, journal = {Soft Matter}, month = {jan}, pages = {5397-5408}, title = {Assembly of multi-flavored two-dimensional colloidal crystals}, url = {https://oadoi.org/10.1039/c7sm01005b}, volume = {13}, year = {2017} } @article{Mahynski2017_2, author = {Mahynski, Nathan A. and Shen, Vincent K.}, doi = {10.1063/1.4974811}, journal = {The Journal of Chemical Physics}, month = {jan}, pages = {044706}, title = {Tuning flexibility to control selectivity in soft porous crystals}, url = {https://oadoi.org/10.1063/1.4974811}, volume = {146}, year = {2017} } @article{Mahynski2017_3, author = {Mahynski, Nathan A. and Blanco, Marco A. and Errington, Jeffrey R. and Shen, Vincent K.}, doi = {10.1063/1.4975331}, journal = {The Journal of Chemical Physics}, month = {feb}, pages = {074101}, title = {Predicting low-temperature free energy landscapes with flat-histogram Monte Carlo methods}, url = {https://aip.scitation.org/doi/10.1063/1.4975331}, volume = {146}, year = {2017} } @article{Mahynski2017_4, author = {Mahynski, Nathan A. and Shen, Vincent K.}, doi = {10.1063/1.4983616}, journal = {The Journal of Chemical Physics}, month = {jun}, pages = {224706}, title = {Controlling relative polymorph stability in soft porous crystals with a barostat}, url = {https://aip.scitation.org/doi/10.1063/1.4983616}, volume = {146}, year = {2017} } @article{Mahynski2017_5, author = {Mahynski, Nathan A. and Errington, Jeffrey R. and Shen, Vincent K.}, doi = {10.1063/1.4996759}, journal = {The Journal of Chemical Physics}, month = {aug}, pages = {054105}, title = {Temperature extrapolation of multicomponent grand canonical free energy landscapes}, url = {https://aip.scitation.org/doi/10.1063/1.4996759}, volume = {147}, year = {2017} } @article{Mahynski2017_6, author = {Mahynski, Nathan A. and Errington, Jeffrey R. and Shen, Vincent K.}, doi = {10.1063/1.5006906}, journal = {The Journal of Chemical Physics}, month = {dec}, pages = {234111}, title = {Multivariable extrapolation of grand canonical free energy landscapes}, url = {https://oadoi.org/10.1063/1.5006906}, volume = {147}, year = {2017} } @article{Mahynski2018, author = {Mahynski, Nathan A. and Jiao, Sally and Hatch, Harold W. and Blanco, Marco A. and Shen, Vincent K.}, doi = {10.1063/1.5026493}, journal = {The Journal of Chemical Physics}, month = {may}, pages = {194105}, title = {Predicting structural properties of fluids by thermodynamic extrapolation}, url = {https://oadoi.org/10.1063/1.5026493}, volume = {148}, year = {2018} } @article{Meng2017, abstract = {AbstractA large body of experimental work has established that athermal colloid/polymer mixtures undergo a sequence of transitions from a disordered fluid state to a colloidal crystal to a second disordered phase with increasing polymer concentration. These transitions are driven by polymer-mediated interparticle attraction, which is a function of both the polymer density and size. It has been posited that the disordered state at high polymer density is a consequence of strong interparticle attractions that kinetically inhibit the formation of the colloidal crystal, i.e., the formation of a non-equilibrium gel phase interferes with crystallization. Here we use molecular dynamics simulations and density functional theory on polymers and nanoparticles (NPs) of comparable size and show that the crystal-disordered phase coexistence at high polymer density for sufficiently long chains corresponds to an equilibrium thermodynamic phase transition. While the crystal is, indeed, stabilized at intermediate polymer density by polymer-induced intercolloid attractions, it is destabilized at higher densities because long chains lose significant configurational entropy when they are forced to occupy all of the crystal voids. Our results are in quantitative agreement with existing experimental data and show that, at least in the nanoparticle limit of sufficiently small colloidal particles, the crystal phase only has a modest range of thermodynamic stability.}, author = {Meng, Dong and Kumar, Sanat K. and Grest, Gary S. and Mahynski, Nathan A. and Panagiotopoulos, Athanassios Z.}, doi = {10.1038/s41524-016-0005-8}, journal = {npj Computational Materials}, month = {jan}, title = {Reentrant equilibrium disordering in nanoparticle–polymer mixtures}, url = {https://doi.org/10.1038/s41524-016-0005-8}, volume = {3}, year = {2017} } @article{Shen2018, author = {Shen, Vincent K. and Siderius, Daniel W. and Mahynski, Nathan A.}, doi = {10.1063/1.5022171}, journal = {The Journal of Chemical Physics}, month = {mar}, pages = {124115}, title = {Molecular simulation of capillary phase transitions in flexible porous materials}, url = {https://aip.scitation.org/doi/pdf/10.1063/1.5022171}, volume = {148}, year = {2018} } @article{Siderius2017, author = {Siderius, Daniel W. and Mahynski, Nathan A. and Shen, Vincent K.}, doi = {10.1007/s10450-017-9879-0}, journal = {Adsorption}, month = {mar}, pages = {593-602}, title = {Relationship between pore-size distribution and flexibility of adsorbent materials: statistical mechanics and future material characterization techniques}, url = {http://europepmc.org/articles/pmc5562161?pdf=render}, volume = {23}, year = {2017} }