3D Printing of an Oil/Water Mixture Separator with In Situ Demulsification and Separation.

Changyou Yan,Shuanhong Ma,Yuxiong Guo,Zhilu Liu,Xiaoqin Zhang,Zhongying Ji,Xiaolong Wang

doi:10.3390/polym11050774

Abstract

Currently, many meshes, membranes, and fabrics with extreme wettability of superhydrophobicity/superoleophilicity, or superhydrophilicity and underwater superoleophobicity are promising candidates for oil/water mixture separation. Nevertheless, a facile yet effective way to design and fabricate porous mesh still remains challenging. In this work, fused deposition modeling (FDM) 3D printing of Fe/polylactic acid (PLA) composites was employed to fabricate superhydrophilic and underwater superoleophobic mesh (S-USM) with hydrogel coatings via the surface polymerization of Fe(II)-mediated redox reaction. In addition, salt of aluminum chloride was incorporated within the hydrogel coating, which was attributed to strengthening the demulsification of oil-in-water emulsions, resulting in efficient separation of oil-in-water mixtures. The S-USM was efficient for a wide range of oil-in-water mixtures, such as dodecane, diesel, vegetable oil, and even crude oil, with a separation efficiency of up to 85%. In this study, the flexible design and fabrication of 3D printing were used for the facile creation of spherical oil skimmers with hydrogel coatings that were capable of removing the floating oil. Most importantly, this work is expected to promote post-treatment processes using 3D printing as a new manufacturing technology and, in this way, a series of devices of specific shape and function will be expanded to satisfy desired requirements and bring great convenience to personal life.

Highlights

Despite the recent emergence and increasing practical feasibility of conventional techniques involving oil skimmers, centrifuges, coalescers, and flotation technologies, the separation of oil/water mixtures cannot be handled when faced with wastewater from metal workshops, textiles, leather, and petrochemicals, as well as frequent oil spill accidents [1,2]
The mesh was fabricated in two orthogonal layers via fused deposition modeling (FDM) 3D printing of Fe/polylactic acid (PLA) composite filaments (Figure S1)
The advantage of FDM 3D printing in feasible designing and free forming was obvious, especially for preparing in the macro millimeter to large scale

Summary

Introduction

Despite the recent emergence and increasing practical feasibility of conventional techniques involving oil skimmers, centrifuges, coalescers, and flotation technologies, the separation of oil/water mixtures cannot be handled when faced with wastewater from metal workshops, textiles, leather, and petrochemicals, as well as frequent oil spill accidents [1,2]. What makes oil/water mixtures difficult to separate is that oil/water mixtures often contain immiscible mixtures and emulsified mixtures in which micro oil/water droplets are under a stable state [3,4,5,6,7]. The key to achieving a high separation efficiency for emulsified oil-in-water mixtures is to break stable oil-in-water emulsions. Extreme wetting materials, such as superhydrophobic/superoleophilic or superhydrophilic and underwater superoleophobic filters [8,9], oil absorptions [10,11,12,13,14,15], and membranes [16,17,18,19], are promising candidates for separating oil-in-water mixtures.

Methods

Results

Conclusion