Polymer Membranes with Vertically Oriented Pores Constructed by 2D Freezing at Ambient Temperature

Abstract

Polymer membranes with well-controlled and vertically oriented pores are of great importance in the applications for water treatment and tissue engineering. On the basis of two-dimensional solvent freezing, we report environmentally friendly facile fabrication of such membranes from a broad spectrum of polymer resources including poly(vinylidene fluoride), poly(l-lactic acid), polyacrylonitrile, polystyrene, polysulfone and polypropylene. Dimethyl sulfone, diphenyl sulfone, and arachidic acid are selected as green solvents crystallized in the polymer matrices under two-dimensional temperature gradients induced by water at ambient temperature. Parallel Monte Carlo simulations of the lattice polymers demonstrate that the directional process is feasible for each polymer holding suitable interaction with a corresponding solvent. As a typical example of this approach, poly(vinylidene fluoride) membranes exhibit excellent tensile strength, high optical transparence, and outstanding separation performance for the mixtures of yeasts and lactobacilli.

Janus Poly(Vinylidene Fluoride) Membranes with Penetrative Pores for Photothermal Desalination

“…The fabrication process of VOPMs is well controlled on the basis of our previously proposed two-dimensional solvent freezing strategy [29]. Dimethyl sulfone (DMSO2) is a good solvent for PVDF at a high temperature.…”

“…The fabrication of VOPM is based on our previously reported method [29]. DMSO2 was used as a crystallizable solvent to prepare a homogenous solution of PVDF.…”

“…In our previous work, vertically oriented porous membranes (VOPMs) were prepared via a thermally induced phase separation process [29]. The growth of solvent crystal was controlled from one side to the other side within the PVDF membrane through a well-designed bidirectional freezing process.…”

Mesoscopic Simulations of Adsorption and Association of PEO-PPO-PEO Triblock Copolymers on a Hydrophobic Surface: From Mushroom Hemisphere to Rectangle Brush

“…Further understanding of the interfacial behaviors and self-assembly processes is necessitated; however, such endeavors are often limited by the availability of fine experimental techniques. Fortunately, various simulation methods, such as Monte Carlo simulation (MC), molecular dynamics (MD), and dissipative particle dynamics (DPD), − are available to solve these problems. It is in principle viable to study the adsorption of polymer molecules at the atomistic level by using molecular dynamics (MD) .…”

Advances in forward osmosis membranes: Altering the sub-layer structure via recent fabrication and chemical modification approaches

“…The preparation process is illustrated in Fig. 5(a) so the polymer solution was added into a mould made of two stainless steel and glass plates [106]. Then the thickness was tailored perfectly and the mould was located in a water bath with various temperatures.…”