DOI: 10.15125/bath-00641
title: Dataset for "3D Printed Contactor for Enhanced Oil Droplets Coalescence"

description: This dataset includes all the original data for this project including the design of the 3D contractors, detailed methodology of preparation and characterisation results, raw data of filtration tests.
description: Preparation and characterization of emulsions
The oil-in-water emulsions were prepared by adding specific amounts of oil (0.3, 0.4, and 0.5 vol %) in 1 L of water. A homogenizer (ULTRA-TURRAX, T 25 basic, IKA) was used to mix the oil with water at 19,000 rpm for 5 min. Volume-weighted oil droplets size distributions were obtained for oil-in-water emulsions using a Malvern Mastersizer X (300 mm lens, 1.2 − 600 μm detection range, dispersion unit controller, 3000 rpm). Triplicate measurements were conducted on discrete samples and the volume median diameter D (v, 0.5) was used to compare between the oil droplet sizes in the feed and the permeate. To visualize the oil layer that had formed during the visual observation tests, a stock solution prepared by mixing sunflower oil with Sudan Blue II with ratio 99.9:0.1 (wt. %) was used. 1 L each of oil-in-water emulsion was prepared by mixing different amounts of (0.3, 0.4 and 0.5 vol%) stock solution with pure water.

Contactor permeance and rejection performance
The demulsification of the oil-in-water emulsions was carried out by using a vacuum filtration setup: 300 ml of oil-in-water emulsions were used in each experimental run: The first 250 ml were passed through the 3D printed contactors using vacuum filtration and collected in a separating funnel. After 1 h, 20 ml samples were taken from the bottom layer of the permeate in the separating funnel for analysis following an established procedure. Three types of 3D printed contactors, Cylindrical, Schwarz–P and Gyroid, were used. 

Visual observation 
The remaining 50 ml of the starting 300 ml emulsion were poured into a burette and a picture (using a Canon EOS 600D) of the top layer was taken every 30 min for 180 min to observe the increase in the thickness of the oil layer with time and quantify the separation rate of the oil phase using the 3D printed contactors and natural separation (Fig.s S9-11). Image J was used to measure the oil layer thickness in the recorded images.

Fabrication and characterization of 3D printed contactors 
The process of translating a digitally designed 3-dimensional object into a printed membrane introduces a novel set of challenges compared to traditional membrane fabrication processes: First, the more complex the object, the higher the resolution required to accurately render the object in 3D. This, in turn, leads to very large digital file sizes. For example, increasing the number of grid points needed to create the implicit surface from 150 to 800 (cfr. Fig. 2a–d), increased the file size of the Gyroid contactor from 50 Mbyte to 1.8 Gbyte. The number of grid points is a measure of the resolution of the printed object. The larger file size not only requires a longer time to transfer the file to the printer (up to 72 h), but ultimately might exceed the handling capacity of the printer software itself. After trial and error, a compromise resolution of 600 grid points was found to provide an adequately high resolution for the 3D printed samples and a manageable digital file.
description: 1. A 3D printer model (ProJet 3500 HD Max printer (3D Systems)) have been used to print the 3D contractors.
2. A contact angle goniometer (OCA machine, Data Physics, Germany) have been used to measure the contact angles.
3. Electron microscopy (JEOL FESEM6301F) have been use to generate micrographs.
4. Atomic force microscopy (AFM; Nanosurf EasyScan 2 Flex, Switzerland) have been used to measure the surface roughness. 
5. MATLAB R2017b have been used to design Schwarz-P and Gyroid 3D contractors.
6. Openscad software have been used to design cylindrical-based 3D contractor.    
7. A homogenizer (ULTRA-TURRAX, T 25 basic, IKA) was used to mix the oil with water.
8. A Malvern Mastersizer X was used to measure oil droplets size distributions. 
9. A turbidity meter (EUTECH TN-100, Thermo-Scientific) was used to determine the oil concentration in the feed and permeate. 
10. The demulsification of the oil-in-water emulsions was carried out by using a vacuum filtration setup.
description: Excel file sheet have been used to arrange the raw data. PowerPoint file have been used to mange the micro graphs