n-Octyltrichlorosilane Modified SAPO-34/PDMS Mixed Matrix Membranes for Propane/Nitrogen Mixture Separation

Abstract

In this study, zeolite molecular sieve SAPO-34/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) were prepared to recover propane. n-Octyltrichlorosilane (OTCS) was introduced to improve compatibility between SAPO-34 and PDMS, and enhance the separation performance of the MMMs. Physicochemical properties of the MMMs were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and water contact angle (WCA). Results showed that, after modification, alkyl chains were successfully grafted onto SAPO-34 without changing its crystal structure, particles in the MMMs were evenly distributed in the base film, and the hydrophobicity of the MMMs was enhanced. Moreover, the effects of SAPO-34 filling content, operating pressure, and feed gas concentration on the separation performance was explored. This indicated that the modification with OTCS effectively enhanced the separation performance of SAPO-34/PDMS MMMs. When the filling content of modified SAPO-34 was 15%, the maximal separation factor of 22.1 was achieved, and the corresponding propane permeation rate was 101 GPU.

Study of the Dissolution and Diffusion of Propane, Propylene and Nitrogen in Polydimethylsiloxane Membranes with Molecular Dynamics Simulation and Monte Carlo Simulation

“…According to previous experimental results [18], we know that C 3 H 8 and C 3 H 6 have a higher transport rate than N 2 in PDMS, though N 2 has a smaller volume than C 3 H 8 and C 3 H 6 . To explain this unusual phenomenon, we need to explore gas transport in PDMS at the molecular level and obtain profound knowledge of this process.…”

Recent Progress of SAPO-34 Zeolite Membranes for CO2 Separation: A Review

“…Since the first report of MMMs in 1970 [ 59 ], extensive research has been conducted to improve the separation performance and industrial implementation for a range of applications such as hydrogen recovery, treatment of natural gas, and air separation [ 60 , 61 , 62 ]. Different types of polymer matrices have been reported with various fillers, such as MOFs [ 63 , 64 , 65 , 66 , 67 ], COFs [ 68 , 69 , 70 , 71 , 72 ], carbon materials [ 73 ], zeolites [ 59 ], and other materials [ 74 , 75 ]. Zeolite materials with their sieving properties and cost-effectiveness on a large scale make them better candidates for gas separation.…”

Novel Polymeric Membranes Preparation and Membrane Process

“…One review article describes the fouling problems in the membrane technology for use in water and wastewater treatment, as well as the methods of both initial treatment and the least-advanced technologies in treatment processes, such as introducing nanochemistry into the area of water treatment [1]. Six research papers illustrated high-performance NF membrane for the lithium recovery from brine [2], molecular dynamics (MD) simulation of gas transporting in polydimethylsiloxane (PDMS) membrane [3], zeolite molecular sieve SAPO-34/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) preparation to recover propane [4], polyvinylidene fluoride (PVDF)-pressurized ultrafiltration membrane on the treatment of steel wastewater and analyzing [5], poly (vinyl alcohol) (PVA)-based MMMs preparation for high ethanol dehydration performance [6], hydrophilizing the polytetrafluoroetylene (PTFE) microfiltration membrane combining of surfactants and cross-linked co-deposition double-layer self-assembly method [7].…”

“…[14]. Two exciting reports [3,4] are included in this Special Issue, both of which are related to the use of dense silicone rubber PDMS membrane. They simulated gas transport in PDMS membranes using BIOVIA Materials Studio (MS, Accelrys Software Inc. San Diego, USA).…”

“…In a C 3 /N 2 mixed gas system, there is a synergistic relationship between gases in the diffusion process during competitive adsorption in the dissolution process. In the second paper [4], the n-Octyltrichlorosilane (OTCS)-modified SAPO-34 was then introduced into the PDMS to prepare SAPO-34 (OTCS)/PDMS MMMs. A propane/nitrogen mixture was employed to study the separation performance of the membrane.…”