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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Effect of dimethyl phthalate contamination on all-silica GLAD quarter-wave plate performances

Phthalate molecular contamination, identified in the Laser Mégajoule target chamber, can severely alter porous coatings' performance, such as glancing angle deposited quarter-wave plates (QWP). QWPs could potentially be used inside this chamber to smooth the intensity of the focal spots on the target. In this study, all-silica QWP coatings were contaminated with dimethyl phthalate. Transmission was lowered due to the absorption of phthalates, and a non-uniform retardance was induced, even after a two-month storage period in air following contamination. Infrared measurements confirmed the presence of bonds associated with phthalates within the coatings due to their sorption and only partial desorption.

Contamination↗
DOE OSTI2026

Electrochemical Deconstruction of Ortho-Phthalate Plasticizers and Recovery of Plasticizing Moieties

Electrochemical methods for the direct reduction of alkyl esters have been understudied but provide a potential advantage for addressing specific waste streams given that such strategies often require only a minimal chemical profile. One such waste stream that could benefit from electrochemical remediation is poly(vinyl chloride) (PVC) plastics. PVC recycling often faces challenges due to the complexity of such waste. Solvent-based recycling methods pose several advantages for addressing post-use PVC; however, such methods are complicated by the high amounts of toxic legacy plasticizers (ortho-phthalates) present in PVC. A potential solution to addressing such phthalates is to address them electrochemically, coupled with recovery of the resulting valuable products. Presented herein is an optimized electrochemical method for ester activation that is leveraged to separate and recover the aromatic and alkyl components of ortho-phthalate plasticizers. The resulting aliphatic alcohols may be reused to prepare other non-toxic plasticizers. This electro-degradation method is demonstrated on six phthalates that have been identified to pose health concerns in addition to plasticizers recovered from commercial samples of PVC.

di-(2-ethylhexyl) phthalate↗
NASA NTRS1972

An etiological study of phthalate self-contamination of spacecraft and contamination from their earthly environs

Phthalates are very objectionable contaminants in space experiments because of their strong absorption in the UV and IR regions of the spectrum. Thus, even minute amounts of these compounds migrating to optical equipment, in test or space flight conditions, can seriously compromise the results of experiments by altering the sensitivity of the functional equipment. Volatility data of the phthalates and other plasticizers are presented in addition to UV spectra of ultrathin films of these same types of compounds. Sources of plasticizer contamination are revealed with special recognition given to di-2-ethylhexyl phthalate (DEHP), the single most ubiquitous plasticizer in use. A surprisingly large percentage of the outgassing condensates from vacuum testing of spacecraft contain DEHP as well as other plasticizers. IR and gas chromatography/mass spectroscopy methods were used to analyze samples from spacecraft. Methods for successful reduction of plasticizers and other contaminants are mentioned.

Gross, F. C.↗
NASA NTRS1975

Acute pulmonary pathology and sudden death in rats following the intravenous administration of the plasticizer, DI (2-ethylhexyl) phthalate, solubilized with Tween surfactants

Intravenous administration of 200-300 mg/kg of di(2-ethylhexyl)phthalate (DEHP) solubilized in aqueous solutions of several Tween surfactants caused respiratory distress in rats. There was a dose-dependent lethality with death generally occurring within 90 minutes after injection. The lungs from DEHP:Tween treated animals were enlarged, generally darkened, and in some cases showed hemorrhagic congestion. Neither the overt symptoms nor the morphologic alterations resulting from DEHP:Tween administration could be reproduced by intravenous administration of aqueous Tween solutions alone. The absence of pulmonary abnormalities following the intravenous administration of DEHP as an aqueous emulsion given either alone or even as soon as 2 minutes after pretreatment with Tween 80, suggests that the specific in vivo interaction between DEHP and Tween surfactants depends on the prior formation of water-soluble micelles of DEHP.

Schulz, C. O.↗
NASA NTRS1975

Fate in humans of the plasticizer, DI (2-ethylhexyl) phthalate, arising from transfusion of platelets stored in vinyl plastic bags

Platelet concentrates were shown to contain 18-38 mg/100 ml of a phthalate plasticizer (DEHP) which arose by migration from the vinyl plastic packs in which the plateletes were prepared and stored. Transfusion of these platelets into 6 adult patients with leukemia resulted in peak blood plasma levels of DEHP ranging from 0.34 - 0.83 mg/100 ml. The blood levels fell mono-exponentially with a mean rate of 2.83 percent per minute and a half-life of 28.0 minutes. Urine was assayed by a method that would measure unchanged DEHP as well as all phthalic acid-containing metabolities. In two patients, at most 60 and 90% of the infused dose, respectively, was excreted in the urine collected for 24 hours post-transfusion. These estimates, however, could be high due to the simultaneous excretion of DEHP remaining from previous transfusions or arising from uncontrolled environmental exposures.

Rubin, R. J.↗
NASA NTRS1990

Use of moments of momentum to predict the crystal habit in potassium hydrogen phthalate

A relatively simple calculation of the moments of momentum predicts the morphological order of crystal faces for potassium hydrogen phthalate. The effects on the habit caused by the addition of monomeric, dimeric, and larger aggregates during crystal growth are considered. The first six of the seven observed crystal faces are predicted with this method.

Barber, Patrick G.↗
NASA NTRS1975

Toxicologic evaluation of the migration of a plasticizer, DI (2-ethylhexyl) phthalate (DEHP) from vinyl plastics

The intravenous administration of DEHP solubilized by means of a number of different detergents leads to respiratory distress and death in rats. At autopsy the lungs are grossly enlarged, edamatous, and hemorrhagic. Light and electron microscopic evaluation of the lungs indicate engorgement of the interalveolar septa with edema fluid and polymorphonuclear leucocytes, degranulation of the leukocytes, and progessive destruction of the endothelial and epithelial cells. Consistent with the conclusion that solubilized DEHP results in a syndrome of "shock lung" is the associated massive fall in arterial blood pressure and the prevention of the lung pathology by pretreatment with pharmacologic doses of an antiinflammatory steroid, methylprednisolone. Evidence is also presented that suggests that the DEHP inadvertently administered to humans during transfusions is also in a solubilized state in the plasma.

Rubin, R. J.↗
DOE OSTI2021

Controlling Polymer Morphology in Blade-Coated All-Polymer Solar Cells

In this report translating all-polymer solar cells from spin-coating to scalable roll-to-roll-compatible fabrication techniques is a critical step toward the application of organic photovoltaics at a scale. Techniques to control polymer crystallization and phase separation during solution printing are essential to obtain high-performance printed organic solar cells. Here, we demonstrate a novel solvent additive approach employing trace amounts of phthalates as additives to control polymer crystallinity and suppress unfavorable phase separation in a representative PTB7-Th/P(NDI2OD-2T) all-polymer solar cell. The best-performing additive increased the blade-coated device performance from 2.09 to 4.50% power conversion efficiency, an over twofold improvement, mitigating the loss in performance that is typically observed during process transfer from spin-coating to blade-coating. It is suggested that the improved device performance stems from a finer polymer phase-separation size and overall improved active layer morphology, evidenced by device characterization data and indirectly supported by grazing incidence wide-angle X-ray scattering analyses. Real-time X-ray diffraction measurements during blade-coating provide mechanistic insights and suggest that the dioctyl phthalate additive may act as a compatibilizer, reducing the demixing of the donor and acceptor polymer during film formation, enabling a smaller phase separation and improved performance. The structural diversity of the class of phthalate additives makes this simple yet effective concept promising for translating other all-polymer material systems to blade-coating and other scalable printing techniques.

14 SOLAR ENERGY↗