Publications by authors named "Linda Schadler"

18 Publications

  • Page 1 of 1

A Peer-Based Strategy to Overcome HPV Vaccination Inequities in Rural Communities: A Physical Distancing-Compliant Approach.

Crit Rev Eukaryot Gene Expr 2021 ;31(1):61-69

KM Consulting, New Jersey, USA.

The human papilloma virus (HPV) vaccine is the world's first proven and effective vaccine to prevent cancers in males and females when administered pre-exposure. Like most of the US, barely half of Vermont teens are up-to-date with the vaccination, with comparable deficits in New Hampshire and Maine. The rates for HPV vaccine initiation and completion are as low as 33% in rural New England. Consequently, there is a compelling responsibility to communicate its importance to unvaccinated teenagers before their risk for infection increases. Messaging in rural areas promoting HPV vaccination is compromised by community-based characteristics that include access to appropriate medical care, poor media coverage, parental and peer influence, and skepticism of science and medicine. Current strategies are predominantly passive access to literature and Internet-based information. Evidence indicates that performance-based messaging can clarify the importance of HPV vaccination to teenagers and their parents in rural areas. Increased HPV vaccination will significantly contribute to the prevention of a broadening spectrum of cancers. Reducing rurality-based inequities is a public health priority. Development of a performance-based peer-communication intervention can capture a window of opportunity to provide increasingly effective and sustained HPV protection. An effective approach can be partnering rural schools and regional health teams with a program that is nimble and scalable to respond to public health policies and practices compliant with COVID-19 pandemic-related modifications on physical distancing and interacting in the foreseeable future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1615/CritRevEukaryotGeneExpr.2021036945DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8128079PMC
March 2021

Dye doped concentric shell nanoparticles for enhanced photophysical performance of downconverting light emitting diodes.

J Colloid Interface Sci 2019 Nov 3;556:753-760. Epub 2019 Sep 3.

Department of Mechanical Engineering, College of Engineering and Mathematical Sciences, University of Vermont, Burlington, VT 05405, United States.

In this study, we examined the potential for perylene dye doped nanoparticles to enhance Light Emitting Diodes (LED) efficacy by minimizing π-π intermolecular aggregation, and enhancing photoluminescence and photostability of the dye molecules in the solid state. Towards this end, we encapsulated perylene dyes, suitably modified with a reactive silica precursor, into silica nanoparticles within a silica-dye-silica concentric layered shell. We found that the fluorescent yield was higher when the dye was embedded in a buried concentric shell within the silica nanoparticles (NPs) compared to an undoped shell/dye doped core nanoparticle morphology or unencapsulated dye with the same net dye concentration in solution. A strong dependence of relative quantum yield on dye doping concentration in the silica-dye-silica nanoparticles was observed. The uniform ∼ 100 nm large silica-dye-silica layered nanoparticles were used to prepare transparent dye doped silica nanoparticle/silicone nanocomposites. Dye doped silica nanoparticle/silicone nanocomposites exhibited higher photostability than the unencapsulated dye samples during long time aging tests under a blue LED with a wavelength of 455 nm at 300 ± 3% mA for 24 h. Novel dye doped layered silica NPs and their nanocomposites offer scope for developing organic luminescent materials into efficient and color-tunable light emitters for low-cost display, lighting, and optical communication applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2019.09.004DOI Listing
November 2019

Size effects in plasma-enhanced nano-transfer adhesion.

Soft Matter 2018 Nov;14(45):9220-9226

Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

Plasma bonding and layer-by-layer transfer molding have co-existed for decades, and here we offer a combination of the two that drives both techniques to the nanoscale. Using fluorinated elastomeric stamps, lines of plasma-treated poly(dimethylsiloxane) (PDMS) were stacked into multi-layer woodpile structures via transfer molding, and we observe a pronounced size effect wherein nanoscale lines (≤280 nm period) require ultra-low plasma dose (<20 J) and fail to bond at the much higher range of plasma dose (600 J to 900 J) recommended in the PDMS plasma bonding literature. The size effect appears to be related to the thickness of the oxide film that develops on the PDMS surface during treatment, and we employ an empirical relationship, , to estimate the thickness of this film in the low plasma dose (<100 J) regime. The empirical relationship shows good agreement with existing studies on plasma-treated PDMS oxide film thickness, and the transition between successful transfer and delamination coincides well with a critical value of the oxide thickness relative to the thickness of the transferred layer. Through peel testing, we identified a transition in failure mode of flat plasma-bonded PDMS consistent with the optimal plasma dose in previous literature but otherwise observed strong, irreversible adhesion even at ultra-low plasma dose. By demonstrating the importance of low plasma dose for plasma-enhanced nano-transfer adhesion, these results advance our understanding of irreversible adhesion of soft materials at the nanoscale and open up new opportunities within the relatively unstudied ultra-low dose plasma treatment regime.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8sm01862fDOI Listing
November 2018

Wetting Regimes for Residual-Layer-Free Transfer Molding at Micro- and Nanoscales.

ACS Appl Mater Interfaces 2017 Oct 3;9(41):36385-36391. Epub 2017 Oct 3.

Center for Lighting Enabled Systems and Applications, Department of Materials Science and Engineering, Rensselaer Polytechnic Institute , 110 8th Street, Troy, New York 12180, United States.

Transfer molding offers a low-cost approach to large-area fabrication of isolated structures in a variety of materials when recessed features of the open-faced mold are filled without leaving a residual layer on the plateaus of the mold. Considering both macroscale dewetting and microscale capillary flow, a proposed map of wetting regimes for blade meniscus coating provides a guide for achieving discontinuous dewetting at maximum throughput. Dependence of meniscus morphology on the azimuthal orientation of the stamp provides insight into the dominant mechanisms for discontinuous dewetting of one-dimensional (1-D) patterns. Critical meniscus velocity is measured and residual-layer-free filling is demonstrated for 1-D patterned soft molds (stamps) with periods ranging from 140 nm to 6 μm. Transfer of isolated lines, and multilayer woodpile structures were achieved through plasma bonding. These results are relevant to other roll-to-roll compatible processes for scalable production of high-resolution structures across large areas.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.7b09402DOI Listing
October 2017

Tunable Multiscale Nanoparticle Ordering by Polymer Crystallization.

ACS Cent Sci 2017 Jul 7;3(7):751-758. Epub 2017 Jun 7.

Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.

While ∼75% of commercially utilized polymers are semicrystalline, the generally low mechanical modulus of these materials, especially for those possessing a glass transition temperature below room temperature, restricts their use for structural applications. Our focus in this paper is to address this deficiency through the controlled, multiscale assembly of nanoparticles (NPs), in particular by leveraging the kinetics of polymer crystallization. This process yields a multiscale NP structure that is templated by the lamellar semicrystalline polymer morphology and spans NPs engulfed by the growing crystals, NPs ordered into layers in the interlamellar zone [spacing of [Formula: see text] (10-100 nm)], and NPs assembled into fractal objects at the interfibrillar scale, [Formula: see text] (1-10 μm). The relative fraction of NPs in this hierarchy is readily manipulated by the crystallization speed. Adding NPs usually increases the Young's modulus of the polymer, but the effects of multiscale ordering are nearly an order of magnitude larger than those for a state where the NPs are not ordered, i.e., randomly dispersed in the matrix. Since the material's fracture toughness remains practically unaffected in this process, this assembly strategy allows us to create high modulus materials that retain the attractive high toughness and low density of polymers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acscentsci.7b00157DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5532707PMC
July 2017

Investigation of dielectric breakdown in silica-epoxy nanocomposites using designed interfaces.

J Colloid Interface Sci 2017 06 4;495:130-139. Epub 2017 Feb 4.

Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29205, United States. Electronic address:

Adding nano-sized fillers to epoxy has proven to be an effective method for improving dielectric breakdown strength (DBS). Evidence suggests that dispersion state, as well as chemistry at the filler-matrix interface can play a crucial role in property enhancement. Herein we investigate the contribution of both filler dispersion and surface chemistry on the AC dielectric breakdown strength of silica-epoxy nanocomposites. Ligand engineering was used to synthesize bimodal ligands onto 15nm silica nanoparticles consisting of long epoxy compatible, poly(glycidyl methacrylate) (PGMA) chains, and short, π-conjugated, electroactive surface ligands. Surface initiated RAFT polymerization was used to synthesize multiple graft densities of PGMA chains, ultimately controlling the dispersion of the filler. Thiophene, anthracene, and terthiophene were employed as π-conjugated surface ligands that act as electron traps to mitigate avalanche breakdown. Investigation of the synthesized multifunctional nanoparticles was effective in defining the maximum particle spacing or free space length (L) that still leads to property enhancement, as well as giving insight into the effects of varying the electronic nature of the molecules at the interface on breakdown strength. Optimization of the investigated variables was shown to increase the AC dielectric breakdown strength of epoxy composites as much as 34% with only 2wt% silica loading.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2017.02.001DOI Listing
June 2017

[email protected] Structured Nanocomposites: A Route to High Dielectric Constant and Low Loss Material.

ACS Appl Mater Interfaces 2016 Sep 16;8(38):25496-507. Epub 2016 Sep 16.

Department of Polymer Science and Engineering, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University , Shanghai 200240, China.

This work reports the advances of utilizing a [email protected] nanostructure to enhance the electrical energy storage capability and suppress the dielectric loss of polymer nanocomposites. Two types of [email protected] barium titanate (BaTiO3) matrix-free nanocomposites were prepared using a surface initiated atom transfer radical polymerization (ATRP) method to graft a poly(2-hydroxylethyle methacrylate)-block-poly(methyl methacrylate) and sodium polyacrylate-block-poly(2-hydroxylethyle methacrylate) block copolymer from BaTiO3 nanoparticles. The inner shell polymer is chosen to have either high dielectric constant or high electrical conductivity to provide large polarization, while the encapsulating outer shell polymer is chosen to be more insulating as to maintain a large resistivity and low loss. Finite element modeling was conducted to investigate the dielectric properties of the fabricated nanocomposites and the relaxation behavior of the grafted polymer. It demonstrates that confinement of the more conductive (lossy) phase in this multishell nanostructure is the key to achieving a high dielectric constant and maintaining a low loss. This promising multishell strategy could be generalized to a variety of polymers to develop novel nanocomposites.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.6b06650DOI Listing
September 2016

Ligand engineering of polymer nanocomposites: from the simple to the complex.

ACS Appl Mater Interfaces 2014 May 6;6(9):6005-21. Epub 2014 Feb 6.

Department of Materials Science and Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.

One key to optimizing the performance of polymer nanocomposites for high-tech applications is surface ligand engineering of the nanofiller, which has been used to either tune the nanofiller morphology or introduce additional functionalities. Ligand engineering can be relatively simple such as a single population of short molecules on the nanoparticle surface designed for matrix compatibility. It can also have complexity that includes bimodal (or multimodal) populations of ligands that enable relatively independent control of enthalpic and entropic interactions between the nanofiller and matrix as well as introduce additional functionality and dynamic control. In this Spotlight on Applications, we provide a brief review into the use of brush ligands to tune the thermodynamic interactions between nanofiller and matrix and then focus on the potential for surface ligand engineering to create exciting nanocomposites properties for optoelectronic and dielectric applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/am405332aDOI Listing
May 2014

Stalking the Materials Genome: A Data-Driven Approach to the Virtual Design of Nanostructured Polymers.

Adv Funct Mater 2013 Dec 24;23(46):5746-5752. Epub 2013 Jun 24.

Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA.

Accelerated insertion of nanocomposites into advanced applications is predicated on the ability to perform a priori property predictions on the resulting materials. In this paper, a paradigm for the virtual design of spherical nanoparticle-filled polymers is demonstrated. A key component of this "Materials Genomics" approach is the development and use of Materials Quantitative Structure-Property Relationship (MQSPR) models trained on atomic-level features of nanofiller and polymer constituents and used to predict the polar and dispersive components of their surface energies. Surface energy differences are then correlated with the nanofiller dispersion morphology and filler/matrix interface properties and integrated into a numerical analysis approach that allows the prediction of thermomechanical properties of the spherical nanofilled polymer composites. Systematic experimental studies of silica nanoparticles modified with three different surface chemistries in polystyrene (PS), poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA) and poly(2-vinyl pyridine) (P2VP) are used to validate the models. While demonstrated here as effective for the prediction of meso-scale morphologies and macro-scale properties under quasi-equilibrium processing conditions, the protocol has far ranging implications for Virtual Design.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/adfm.201301744DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4981086PMC
December 2013

Enzyme-based listericidal nanocomposites.

Sci Rep 2013 ;3:1584

Department of Chemical and Biological Engineering, Center for Biotechnology & Interdisciplinary Studies, and Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

Cell lytic enzymes represent an alternative to chemical decontamination or use of antibiotics to kill pathogenic bacteria, such as listeria. A number of phage cell lytic enzymes against listeria have been isolated and possess listericidal activity; however, there has been no attempt to incorporate these enzymes onto surfaces. We report three facile routes for the surface incorporation of the listeria bacteriophage endolysin Ply500: covalent attachment onto FDA approved silica nanoparticles (SNPs), incorporation of SNP-Ply500 conjugates into a thin poly(hydroxyethyl methacrylate) film; and affinity binding to edible crosslinked starch nanoparticles via construction of a maltose binding protein fusion. These Ply500 formulations were effective in killing L. innocua (a reduced pathogenic surrogate) at challenges up to 10(5) CFU/ml both in non-growth sustaining PBS as well as under growth conditions on lettuce. This strategy represents a new route toward achieving highly selective and efficient pathogen decontamination and prevention in public infrastructure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep01584DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3613805PMC
October 2013

Bimodal surface ligand engineering: the key to tunable nanocomposites.

Langmuir 2013 Jan 7;29(4):1211-20. Epub 2012 Nov 7.

Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

Tuning the dispersion of inorganic nanoparticles within organic matrices is critical to optimizing polymer nanocomposite properties and is intrinsically difficult due to their strong enthalpic incompatibility. Conventional attempts to use polymer brushes to control nanoparticle dispersion are challenged by the need for high graft density to reduce particle core-core attractions and the need for low graft density to reduce the entropic penalty for matrix penetration into the brush. We validated a parametric phase diagram previously reported by Pryamtisyn et al. (Pryamtisyn, V.; Ganesan, V.; Panagiotopoulos, A. Z.; Liu, H.; Kumar, S. K. Modeling the Anisotropic Self-Assembly of Spherical Polymer-Grafted Nanoparticles. J. Chem. Phys.2009, 131, 221102) for predicting dispersion of monomodal-polymer-brush-modified nanoparticles in polymer matrices. The theoretical calculation successfully predicted the experimental observation that the monomodal-poly(dimethyl siloxane) (PDMS)-brush-grafted TiO(2) nanoparticles can only be well dispersed within a small molecular weight silicone matrix. We further extended the parametric phase diagram to analyze the dispersion behavior of bimodal-PDMS-brush-grafted particles, which is also in good agreement with experimental results. Utilizing a bimodal grafted polymer brush design, with densely grafted short brushes to shield particle surfaces and sparsely grafted long brushes that favor the entanglement with matrix chains, we dispersed TiO(2) nanoparticles in high molecular weight commercial silicone matrices and successfully prepared thick (about 5 mm) transparent high-refractive-index TiO(2)/silicone nanocomposites.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/la3036192DOI Listing
January 2013

Graphene oxide filled nanocomposite with novel electrical and dielectric properties.

Adv Mater 2012 Jun 9;24(23):3134-7. Epub 2012 May 9.

Department of Material Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/adma.201200827DOI Listing
June 2012

Preparation and optical properties of indium tin oxide/epoxy nanocomposites with polyglycidyl methacrylate grafted nanoparticles.

ACS Appl Mater Interfaces 2011 Sep 18;3(9):3638-45. Epub 2011 Aug 18.

Department of Materials Science and Engineering and Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.

Visibly highly transparent indium tin oxide (ITO)/epoxy nanocomposites were prepared by dispersing polyglycidyl methacrylate (PGMA) grafted ITO nanoparticles into a commercial epoxy resin. The oleic acid stabilized, highly crystalline, and near monodisperse ITO nanoparticles were synthesized via a nonaqueous synthetic route with multigram batch quantities. An azido-phosphate ligand was synthesized and used to exchange with oleic acid on the ITO surface. The azide terminal group allows for the grafting of epoxy resin compatible PGMA polymer chains via Cu(I) catalyzed alkyne-azide "click" chemistry. Transmission electron microscopy (TEM) observation shows that PGMA grafted ITO particles were homogeneously dispersed within the epoxy matrix. Optical properties of ITO/epoxy nanocomposites with different ITO concentrations were studied with an ultraviolet-visible-near-infrared (UV-vis-NIR) spectrometer. All the ITO/epoxy nanocomposites show more than 90% optical transparency in the visible light range and absorption of UV light from 300 to 400 nm. In the near-infrared region, ITO/epoxy nanocomposites demonstrate low transmittance and the infrared (IR) transmission cutoff wavelength of the composites shifts toward the lower wavelength with increased ITO concentration. The ITO/epoxy nanocomposites were applied onto both glass and plastic substrates as visibly transparent and UV/IR opaque optical coatings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/am200841nDOI Listing
September 2011

Anisotropic self-assembly of spherical polymer-grafted nanoparticles.

Nat Mater 2009 Apr 22;8(4):354-9. Epub 2009 Mar 22.

Department of Chemical Engineering, Columbia University, New York, New York 10027, USA.

It is easy to understand the self-assembly of particles with anisotropic shapes or interactions (for example, cobalt nanoparticles or proteins) into highly extended structures. However, there is no experimentally established strategy for creating a range of anisotropic structures from common spherical nanoparticles. We demonstrate that spherical nanoparticles uniformly grafted with macromolecules ('nanoparticle amphiphiles') robustly self-assemble into a variety of anisotropic superstructures when they are dispersed in the corresponding homopolymer matrix. Theory and simulations suggest that this self-assembly reflects a balance between the energy gain when particle cores approach and the entropy of distorting the grafted polymers. The effectively directional nature of the particle interactions is thus a many-body emergent property. Our experiments demonstrate that this approach to nanoparticle self-assembly enables considerable control for the creation of polymer nanocomposites with enhanced mechanical properties. Grafted nanoparticles are thus versatile building blocks for creating tunable and functional particle superstructures with significant practical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nmat2404DOI Listing
April 2009

Nanocomposites. Model interfaces.

Authors:
Linda Schadler

Nat Mater 2007 Apr;6(4):257-8

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nmat1873DOI Listing
April 2007

Embedded carbon-nanotube-stiffened polymer surfaces.

Small 2005 Mar;1(3):317-20

Department of Materials Science, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.200400064DOI Listing
March 2005

Quantitative equivalence between polymer nanocomposites and thin polymer films.

Nat Mater 2005 Sep 7;4(9):693-8. Epub 2005 Aug 7.

Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

The thermomechanical responses of polymers, which provide limitations to their practical use, are favourably altered by the addition of trace amounts of a nanofiller. However, the resulting changes in polymer properties are poorly understood, primarily due to the non-uniform spatial distribution of nanoparticles. Here we show that the thermomechanical properties of 'polymer nanocomposites' are quantitatively equivalent to the well-documented case of planar polymer films. We quantify this equivalence by drawing a direct analogy between film thickness and an appropriate experimental interparticle spacing. We show that the changes in glass-transition temperature with decreasing interparticle spacing for two filler surface treatments are quantitatively equivalent to the corresponding thin-film data with a non-wetting and a wetting polymer-particle interface. Our results offer new insights into the role of confinement on the glass transition, and we conclude that the mere presence of regions of modified mobility in the vicinity of the particle surfaces, that is, a simple two-layer model, is insufficient to explain our results. Rather, we conjecture that the glass-transition process requires that the interphase regions surrounding different particles interact.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nmat1447DOI Listing
September 2005

Aggregation behavior of single-walled carbon nanotubes in dilute aqueous suspension.

J Colloid Interface Sci 2004 Dec;280(1):91-7

Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

The aggregation behavior of colloidal single-walled carbon nanotubes (SWNT) in dilute aqueous suspensions was investigated using a novel light scattering measurement technique. The aggregation of SWNT in three suspensions was examined: (1) nanotubes after acid treatment; (2) as-received nanotubes stabilized by a nonionic surfactant; and (3) acid-treated nanotubes with nonionic surfactant. Continuous light scattering measurements of the SWNT suspensions (probing the 38-436 nm length scale) made over two weeks showed that the nanotubes in each sample formed networks with fractal-like structures. The as-received nanotubes were stable over the measurement period, while the acid-treated nanotube suspension showed greater dispersion variability over time, yielding looser structures at large length scales and more compact structures at smaller length scales. The addition of surfactant to the acid-treated suspension significantly enhanced nanotube dispersion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2004.07.028DOI Listing
December 2004
-->