Title: A ReaxFF molecular dynamics study of molecular-level interactions during binder jetting 3D-printing

Abstract

In the present work, we study one of the major additive manufacturing processes, i.e., the binder jetting printing (BJP) process, at the molecular level through atomistic-scale level representations of powders and binder solutions with chromium-oxide (Cr-oxide) nanoparticles and water-based diethylene glycol solutions, respectively. The results show that both diethylene glycol and water contribute to the bonding of Cr-oxide particles during the print and curing stages by forming a hydrogen bond network. Heating the system to the burn-out temperature results in the oxidation of diethylene glycol and the decomposition of the hydrogen bond network. Subsequently, Cr-oxide particles are partially sintered by forming Cr–O bonds. The final sintering facilitates further Cr–O bond formation. Additionally, the influence of the chemical composition of the binder solution is investigated by performing ReaxFF molecular dynamics simulations on two sets of systems, which control the number of water and diethylene glycol molecules, respectively. Our results demonstrate that adding both diethylene glycol and water to the binder solution can raise the number of “useful” hydrogen bonds, resulting in a higher breaking strength at the print and curing stages. During the burn-out and sintering stages, the influence of water on the breaking strength is not obvious. In contrast, anmore » optimal quantity of binder species exists for the breaking strength after sintering. A comparison of the ReaxFF molecular dynamics simulations using 2-ethoxyethanol, diethylene glycol and 1-(2,2,2-trihydroxyethoxy)ethane-2,2,2-triol as the binder phase indicates that an increasing number of hydroxyl groups leads to higher breaking strength at the print and curing stages. The findings from this study can be extended to identify the optimal binder chemistry, curing and sintering conditions for different material systems.« less

Authors:

Gao, Yawei  ^[1];

• Search DOE PAGES for author "Gao, Yawei"
• Search DOE PAGES for ORCID "0000-0002-2567-2853"
• Search orcid.org for ORCID "0000-0002-2567-2853"

Shin, Yun Kyung  ^[1];

• Search DOE PAGES for author "Shin, Yun Kyung"
• Search DOE PAGES for ORCID "0000-0001-8198-001X"
• Search orcid.org for ORCID "0000-0001-8198-001X"

Martinez, Daniel  ^[1];

• Search DOE PAGES for author "Martinez, Daniel"
• Search DOE PAGES for ORCID "0000-0002-6505-6836"
• Search orcid.org for ORCID "0000-0002-6505-6836"

Manogharan, Guha  ^[1];

• Search DOE PAGES for author "Manogharan, Guha"
• Search DOE PAGES for ORCID "0000-0002-9756-1220"
• Search orcid.org for ORCID "0000-0002-9756-1220"

van Duin, Adri C. T.  ^[1]

• Search DOE PAGES for author "van Duin, Adri C. T."
• Search DOE PAGES for ORCID "0000-0002-3478-4945"
• Search orcid.org for ORCID "0000-0002-3478-4945"

---

+ Show Author Affiliations

1. Pennsylvania State Univ., University Park, PA (United States)

Publication Date:

2019-09-10

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Multi-Scale Fluid-Solid Interactions in Architected and Natural Materials (MUSE); Univ. of Utah, Salt Lake City, UT (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1595984

Alternate Identifier(s):

OSTI ID: 1562734

Grant/Contract Number:  

SC0019285; SC001928

Resource Type:

Accepted Manuscript

Journal Name:

Physical Chemistry Chemical Physics. PCCP

Additional Journal Information:

Journal Volume: 21; Journal Issue: 38; Journal ID: ISSN 1463-9076

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY