Gel Samples Research Articles

Preparation and researching the properties of organic aerogels based on epoxy resins

The aim of this work was to develop methods for the synthesis of organic gels based on epoxy resins and the production of their aerogels. In general, aerogels are obtained from gel samples that consist of a high-molecular spatial network and a low-molecular dispersion medium - solvent. Various drying methods are used to remove liquid from gel pores, the most reliable of which, allowing to obtain samples of aerogels with undamaged spatial structure, is drying in supercritical fluid medium. As a result of the work the aerogels of different density were obtained, the dependence of density on the solvent content in the samples was revealed. The obtained aerogels were characterized by density, studied by infrared spectroscopy to assess the degree of polymerization of the resin, as well as using the BET method to determine the specific surface area of the samples and obtain its dependence on the catalyst content and curing conditions.

Measurement of mass attenuation coefficient of polyvinyl alcohol (PVAL) as breast tissue equivalent material in the photon energy range of 16.61–25.26 keV

Medical physics phantom is commonly designed to mimic physical properties of human tissue. Phantom is widely used to provide quantitative and qualitative information upon its interaction with ionizing radiation in medical imaging, radiation dosimetry and treatment planning procedures. This study was carried out to fabricate a potential medical physics phantom material for mammography using polyvinyl alcohol (PVAL). The mass attenuation coefficients (μ/ρ ) of the PVAL gel samples were calculated based on the measurement of attenuation coefficient studies with low photon energy. The gel samples were prepared at 4 concentrations (5, 10, 15 and 20 %) of PVAL solution. Single photon beam transmission in the energy range between 16.61 and 25.26 keV was used to determine the μ/ρ of the PVAL gel. The low photon energy was chosen as the effective energy used in mammography is in a range between 17.5 to 22.6 keV. This was achieved by using the X-ray fluorescent (XRF) configuration. The experimental μ/ρ were compared with theoretical values of water and breast tissue calculated by using the XCOM computer program. The measured value of μ/ρ of the PVAL gels agreed with the XCOM values of water and breast tissue. The 5% and 10% PVAL gel samples were the closest to water while the 20% PVAL was the closest to breast tissue.

Microwave assisted freezing part 1: Experimental investigation and numerical modeling

The aim of this study was to develop an innovative process dedicated to enhancing the quality of frozen food using microwaves. A microwave assisted freezing device was designed at the laboratory scale to perform experiments in controlled conditions. Small samples of methylcellulose gels were frozen using nitrogen gas in a TE10 waveguide, where microwaves at 2.45 GHz were emitted intermittently or continuously. A numerical model was also developed to obtain results difficult to measure such as the local electric field and the corresponding energy density. The phase change part of the model was based on an enthalpy formulation and on the growth of spherical ice crystals. An original “hybrid 2D-3D” solving methodology was used to reduce the duration of the simulations. Favourable comparisons between the predicted temperatures and the experimental data highlighted the relevance of the models used for the thermophysical and dielectric properties. The analysis of the interactions between microwaves and matter, performed with numerical simulations, revealed the role of the freezing front as a boundary. The strong influence of sample size and of dielectric properties on the power density distribution were also illustrated when comparing our results with those published previously. The scientific knowledge obtained through this study and the original structure of the numerical model will be used to optimize microwave assisted freezing and link the process parameters to the reduction of ice crystal size highlighted in the companion paper. Industrial relevanceMicrowave assistance during freezing can improve frozen product quality by reducing ice crystal size. This innovative and promising process has not yet been given much attention. Developing an accurate model which describes microwave – matter interactions during phase change permits numerical simulations that can facilitate the design of industrial equipment, and determine optimal product dimensions.

Hyaluronic acid-based shape memory cryogel scaffolds for focal cartilage defect repair

Purpose: Traumatic joint injuries can result in focal cartilage defects that regenerate poorly due to a lack of blood supply and low chondrocyte density. Cell-laden hydrogel scaffolds are under study but provide little flexibility in modulating their pore size, interconnectivity, swelling and stiffness, properties required for a conducive biomimetic environment. In this study, we engineered an injectable and biomimetic shape memory hyaluronic acid (HA)-based cryogel scaffolds with a macroporous and highly interconnected network in three-dimensions seeded with chondrocytes. Due to their unique ability to withstand up to 90% strains and rapidly recover their shape back, they can be arthroscopically delivered to fill up focal chondral defects for cartilage repair. Here we studied whether chondrocytes encapsulated within cryogels remain viable and metabolically active following injection and provide a superior micro-environment than conventional (nanoporous) hydrogels for cartilage regeneration. We also investigated how RGD-functionalized cryogel affects chondrocyte adhesion, migration and proliferation. Methods: Synthesis of HA-based Cryogels and Hydrogels: HA cryogels were prepared using HA modified with glycidyl methacrylate (HAGM) and either Acryl-PEG-G4RGDS to synthesis gels functionalized with RGD (Cryo RGD+) or Acryl-PEG-methoxy to synthesize gels without RGD (Cryo RGD-) in deionized (DI) water. The mixture was cast in 6 mm diam x 1.5 mm cylindrical discs using APS/TEMED as our initiator system. The samples were frozen at -20°C and allowed to cryopolymerize overnight. Next, cryogels were brought to RT and washed/sanitized prior to cell seeding. HA hydrogels (Hydro RGD+) were fabricated via photopolymerization by mixing HAGM, RGD, and lithium phenyl-2,4,6- trimethylbenzoylphosphinate (LAP) photo-initiator in DI water. Chondrocyte seeding and in-vitro culture:Chondrocytes harvested from calf knee femoral condyle cartilage were seeded onto each scaffold and cultured for 15 days. Injectability test: Cell-laden cryogels were incubated overnight to enable complete cell adhesion and subsequently syringe injected through a 16-gauge needle before incubation for another 24h following which cell viability and metabolism were quantified. Biochemical analysis: At the end of 15-day culture, gel samples were digested to quantify the cell metabolism (Alamar Blue), DNA (PicoGreen) and GAG (DMMB) content. Cell viability and cytoskeleton staining: Gel samples were fixed and stained for nucleus, actin, dead cells and confocal imaged at 40x. Results: Shape memory HA-based cryogels fully recovered their shape back following syringe injection through a 16-gauge needle without impacting cell metabolism or viability (Figs 1A-C). Scanning electron microscopy (SEM) images showed an average pore size of 49.2 ± 15 μm (Fig 1D) rendering a macroporous structure with high interconnectivity, which was 7x higher than hydrogels (Fig 1E). This unique macrostructural architecture enables efficient transport of nutrients and metabolites thereby offering a superior microenvironment for chondrocytes; both cell metabolism and GAG content was 2x higher in cryogels than hydrogels after 15-day culture (Figs 1F-G). Additionally, a significant amount of GAG (∼70 μg) was released from both cryogels into media owing to their macroporous structure; no released GAG was measured in media from Hydro RGD+ (Fig 1G). The presence of RGD (cell-adhesion peptide) did not improve cell adhesion or biosynthesis rates. Chondrocytes formed larger organoid-like structures in Cryo RGD- while remaining homogenously dispersed in the presence of RGD in Cryo RGD+ (Fig 1H). Conclusions: Syringe injectable HA-based shape memory cryogels provide a conducive microenvironment for chondrocyte adhesion, proliferation and matrix biosynthesis for use in repair of cartilage defects.

Facile Identification and Isolation of Protease Using SDS-PAGE and Zymography

Purification and identification of novel proteases is critical in the development of new therapeutic drugs, such as those for ischemic stroke. However, it's a time-consuming and expensive job to purify enzymes from natural sources. Furthermore, even if the process is completed, the enzyme could be a known protease. Zymography is a protease-confirming assay, but its molecular weight is hard to be accurately measured due to background noise and the broad zone of lysis. Moreover, a sample in a zymography gel cannot be used for protein identification because of the staining substrate in the gel. However, a protease in an unstained SDS-PAGE gel is not damaged by staining buffer and its proteolytic potential will be maintained and be identified, even though these bands are invisible. In this research, to take advantage of both zymography and unstained SDS-PAGE, each band in an unstained SDS-PAGE gel was cut and transferred to a zymography gel. Through this method, bands on the SDS-PAGE gel and the accompanying electroblotted membrane could be used to confirm the target proteolytic activity. Screened samples could be used for protease identification and to check for novelty.

Structure and Properties of Biodegradable Poly (Xylitol Sebacate-Co-Butylene Sebacate) Copolyester.

In this work, a bio-based copolyester with good mechanical properties was synthesized and characterized in terms of structure, main properties and biodegradability Determining the chemical structure of such materials is important to understand their behavior and properties. Performing an extraction of insoluble cross-linked polymer using different solvents allowed us to analyze how the polymer behaves when subjected to different chemical environments, and to obtain soluble samples suitable for more in-depth analysis. Chemical structure of poly (xylitol sebacate-co-butylene sebacate) was determined by a 1H NMR and FTIR analysis of both prepolymer gel sample and samples obtained by extraction of cross-linked polymer using different solvents. Block structure of the copolymer was confirmed by both NMR and DSC. Gel fraction, swelling value, water contact angle, and mechanical properties were also analyzed. Biodegradability of this material was confirmed by performing enzymatic and hydrolytic degradation. Synthesizing sugar-alcohol based copolyester using three monomers leads to obtaining a material with interesting chemical structure and desirable mechanical properties comparable to conventional elastomers.

Effect of the glucono-δ-lactone concentration on the sensitivity and stability of PVA-GTA-I radiochromic gel dosimeter

The present study explored the influence of the varying concentrations of a proton generator, glucono-δ-lactone (GDL), promoting a cross-linking of the matrix to the dose-response of a PVA-GTA-I radiochromic gel dosimeter. This gel dosimeter was composed of iodide and polyvinyl alcohol crosslinked with glutaraldehyde (GTA) and combined with additives of GDL and fructose. Six sets of gel samples with GDL concentrations ranging from 50 to 300 mM was irradiated with 1–10 Gy doses using 137Cs gamma-rays. Dose response and temporal stability of the absorbance in the gel dosimeter as a function of the GDL concentration were investigated. The dose-response data showed good linearities in the dose range of 0–10 Gy from all GDL concentrations measured 48 h post-irradiation. The sensitivity became higher with increasing GDL concentration, but smaller increments were observed at higher GDL concentrations and then completely saturated around 250 mM. The recorded sensitivities from the PVA-GTA-I gel dosimeters were 3–4 times higher than PVA-I and LCV micelle gel dosimeters. Temporal stability data showed a similar trend in GDL concentrations of 100–300 mM, where a sharp increase of absorbance was seen in the first 24 h and then small fluctuations were observed up to 168 h post-irradiation. Meanwhile, the samples with 50 mM of GDL showed a gradual increase in absorbance after 48 h post-irradiation. Higher GDL concentrations tended to increase the rate of auto-oxidation.

Impact of unripe banana flour on water states, rheological behaviour and structural properties of myofibrillar protein composite gel

Unripe banana flour with particle sizes of 75, 100 and 150 μm (T75, T100, and T150) was incorporated into myofibrillar protein to investigate their effects on water states, rheology, texture properties and microstructure. T75 and T100 had significantly higher water holding capacity and generated harder composite gel compared with control and T150 (P < 0.05). Gelatinization of unripe banana flour (UBF) components including starch and fibers increased the G′ during the heating (20–80 °C) of the MP composite gel samples. T150 added in the gel samples lowered the hardness values and generated less dense and compact microstructure during gelling-forming. T2 relaxation times were significantly lowered with the addition of UBF particle sizes, which entrapped more water molecules (T21 population) within the composite gel. The particle size of UBF differently influenced the functionality of MP composite gel. However, UBF could be an efficient ingredient with the capacity to increase water retention and texture and improve the rheology as well as microstructure of the final MP composite gel system.

Effect of Initial Conformation on the Starch Biopolymer Film Formation Studied by NMR.

The formation of a rigid porous biopolymer scaffold from aqueous samples of 1% w/v (suspension) and 5% w/v (gel) corn starch was studied using optical and nuclear magnetic resonance (NMR) techniques. The drying process of these systems was observed using a single-sided NMR scanner by application of the Carr–Purcell–Meiboom–Gill pulse sequence at different layer positions. The echo decays were analyzed and spin–spin relaxation times (T2) were obtained for each layer. From the depth dependent T2 relaxation time study, it was found that the molecular mobility of water within the forming porous matrix of these two samples varied notably at different stages of film formation. At an intermediate stage, a gradual decrease in mobility of the emulsion sample towards the air–sample interface was observed, while the gel sample remained homogeneous all along the sample height. At a later stage of drying, heterogeneity in the molecular dynamics was observed in both samples showing low mobility at the bottom part of the sample. A wide-angle X-ray diffraction study confirmed that the structural heterogeneity persisted in the final film obtained from the 5% corn starch aqueous sample, whereas the film obtained from the 1% corn starch in water was structurally homogeneous.

Effect of microbial transglutaminase on the mechanical properties and microstructure of acid-induced gels and emulsion gels produced from thermal denatured egg white proteins

In the current study, the impact of microbial transglutaminase (MTGase)-mediated crosslinking on the thermally denatured egg white protein (TD-EWP) made in alkaline pH in relation to their gelling properties of in gel and emulsion gel systems was investigated. Unlike native EWP that was not a good substrate for MTGase due to its compact structure, SDS-PAGE and gel solubility data showed the TD-EWP was sufficiently cross-linked by MTGase. The MTGase significantly (p < 0.05) increased the gel strength, fracture stress, fracture strain, and TPA parameters and decreased the frequency dependence of elastic modulus and stress dependence of creep compliance of TD-EWP gel and emulsion gel samples. The enhanced mechanical properties of the TE-EWP gelled samples treated with MTGase may be suitable for delivering sensitive compounds as well as in fabricating tailored scaffolds in tissue engineering and biomedical products.

Feasibility Study of Polymer Gel Dosimetry Using a 3D Printed Phantom for Liver Cancer Radiotherapy

In this study, a new three-dimensional (3D) volumetric dosimetry method utilizing gel dosimetry with a patient-specific (PS) 3D-printed phantom was developed. A PS 3D-printed phantom that closely mimics the actual tumor and surrounding tissues was demonstrated using a 3D printer (3Dison Plus, Lokit, Korea). MAGAT normoxic polymer gel was filled in the tumor-shaped cavity of the 3D-printed phantom to represent the real tumor. Seven identical gel samples for dosimetric calibration were irradiated at different doses and scanned using magnetic resonance imaging. A chlorinated polyethylene filament was utilized as the 3D printing material. The two-dimensional gamma passing rates using the film were 96.1% and 84.3% for the 3%/3 mm and the 2%/1 mm dose accuracy/distance-to agreement criteria, respectively. The radiation dose-R2 (relaxation rate) calibration, with a coefficient of determination (R2) of 0.997, was applied for the absolute dose calibration. The overall gross tumor volume shape and the dose distribution of the gel measurement agreed reasonably well with the plan results. The 3D gamma passing rate was 91.2% for the 3%/3 mm criteria and decreased to 82.3% for the 2%/1 mm criterion. Our results suggest that polymer gel dosimetry with the 3D-printed phantom allows direct validation of the 3D dose distribution.

Unsteady Mass Transfer of Nutrients in Gels with Channels of Different Spatial Structures

The dynamics of the development of immobilized cells in a gel under conditions of limited mass transfer of nutrients across the interface was considered. The goal of this study was to find methods for effective cultivation of living microorganisms in the gel due to the correct choice of the structure of internal channels, when nutrients are delivered to the gel by the convective-diffusion mechanism. The variation of the relative intensity of transmitted light along the height of the agarose gel sample with living yeast cells during nutrient solution diffusion from the surface with time was determined by spectroscopy. The depth of the gel layer at which the vital activity of microorganisms is provided was evaluated. The possibility of forming time-stable linear and branching channels in the gel was established experimentally. The possibility of their stable use for convective supply of nutrient in the volume was verified. The tendencies of diffusion of nutrients from the channels in the gel with immobilized cells were determined. The 3D structure of channels that provides an increase in the efficiency of cell nutrition in the gel volume was discussed.

Enhancing laccase‐induced soybean protein isolates gel properties by microwave pretreatment

Soybean protein isolate (SPI) is an important food ingredient used to prepare for soy products. However, protein gel formed from individual SPI exhibits poor gelation properties. In this study, effects of microwave pretreatment at various power (0–600 W) on gel properties of laccase-induced gel were investigated. After microwave pretreating, gel strength of treated samples was over 2.2 times that of untreated. Microwave heating dramatically promoted water-holding capacity and storage modulus of laccase-induced SPI gel. Marked reducing happened in free SH group, since laccase catalyzed cross-linking between phenols and its derivatives, which facilitated the connection of disulfide bonds. In addition, microwave pretreatment changed the secondary structure of the gel samples as determined by Fourier transform infrared spectroscopic analysis. Intuitively, a more compact structure was observed by SEM. Hence, microwave pretreatment is effective in improving the gelation properties of laccase-induced SPI gel and may be used as an effective method in food industry. Practical applications As an indispensable ingredient, Soybean protein isolate (SPI) was wildly used in food industry to produce kinds of soy products. However, its poor gel properties impeded a further application of this low-cost ingredient. In this study, SPI was pretreated by microwave which destroyed its compact structure and exposed the reactive sites of enzyme. Then, microwave pretreatment SPI was induced by laccase to catalyze cross-linking between phenols and its derivatives since the groups were common exist in SPI. The laccase-induced SPI gel couple with microwave pretreatment possessed a more excellent gel property, which can be potentially used to produce high-quality soy products in food industry.

EFFECT OF TERPENES AS PENETRATION ENHANCERS ON THE RELEASE AND PERMEATION KINETICS OF MELOXICAM GELS FORMULATIONS

Introduction: The transdermal route of administration has been extensively accepted as one of the potential route for the local and systemic delivery of drugs. The greatest obstacle in drug absorption is the highly organized stratum corneum (SC), which hinder drug transport. The probable solution leads to inclusion of penetration enhancers for reversibly disorganizing the barrier characteristic of stratum corneum. Objective: The main objective of the research work was to study the influence of peppermint oil, lemongrass oil, clove oil and turpentine oil as penetration enhancers on the percutaneous absorption of Meloxicam (ME) from a Carbopol 934 based gel formulation. Materials and Methods: ME gel sample was divided into 5 batches i.e., F1, F2, F3, F4, F5. Except F1, all other batches were incorporated with penetration enhancers (5% w/w) namely peppermint oil, clove oil, lemongrass oil and turpentine oil. The formulations were further evaluated for in-vitro drug release studies using a standard cellophane membrane at 37± 0.5˚ C in phosphate buffer pH 7.4 and a comparative anti-inflammatory activity was conducted using rat paw edema method. Result and Discussion: In-vitro permeation studies using a standard cellophane membrane showed that the rank order of enhancement ratio (ERflux) for Meloxicam as peppermint oil (1.414) &gt; clove oil (1.353) &gt; lemongrass oil (1.326) &gt; turpentine oil (1.272) proving peppermint oil as the most competent penetration enhancer for Meloxicam. Further In- vivo anti-inflammatory activity were carried out using the standard rat paw edema method. The in vivo studies revealed that gel containing peppermint, clove, lemongrass and turpentine exhibited 2.53, 2.0, 1.9 and 1.38 times higher anti-inflammatory effect as compared to meloxicam (standard). Conclusion: It can be concluded from the study that all the 4 terpenes significantly increases the permeation of meloxicam gels and can be used as effective penetration enhancers.

The influence of magnetic nanoparticle concentration with dextran polymers in agar gel on heating efficiency in magnetic hyperthermia

Abstract The article presents the results of research on the effect of magnetic hyperthermia performed on agar gel samples containing magnetite nanoparticles coated with dextran polymers for different molar weight M (150 kDa, 70 kDa, and 40 kDa). Regardless of the difference in molar dextran weights, these samples differed in a mass concentration of nanoparticles in the ferrogel C0 (1.602 mg/cm3, 2.506 mg/cm3, 3.311 mg/cm3, and 4.218 mg/cm3). In the case of the highest magnetic field value H (20 kA·m−1), the specific loss power SPL reaches 70 W·g−1 for nanoparticles with 150 kDa dextran at a concentration of nanoparticles C0 = 1.602 mg/cm3. An oscillating magnetic field with an amplitude up to 20 kA·m−1 and a frequency of 357 kHz was used in the study.

Assessment of photon energy and dose rate dependence of U-NIPAM polymer gel dosimeter

One of the main drawbacks of NPAM gel dosimeter is its relatively low R2-dose sensitivity. Recently, the sensitivity of NIPAM gel dosimeter has been improved by adding urea and this new formula gel dosimeter was named U-NIPAM (Urea and NIPAM). In the current project, photon energy and dose rate dependence of optimized U-NIPAM gel dosimeter (with 3% urea) was assessed by MRI technique. The gel samples were fabricated under normal atmospheric conditions and after 1 day, they were exposed to photon energies of 6 and 15 MV and dose rates of 300, 400, and 500 cGy/min. Then, MRI responses (R2) of the U-NIPAM gel samples were analyzed at 12, 36, 72, 168 h after the irradiation process. The dosimetric evaluation of optimized U-NIPAM gel dosimeter characteristics at 12 h after the irradiation process resulted to following findings: 1) different photon energies (6 and 15 MV) have significant effect on the R2-dose sensitivity of gel dosimeter in 0–7 Gy dose range (P < 0.05), 2) the R2-dose sensitivity of gel dosimeter does not significantly change with different dose rate (300–500 cGy/min) in 0–7 Gy dose range (P˃0.05), 3) the obtained dose resolution for evaluated various photon energies and dose rates ranges from 0.06 Gy to 0.20 Gy. Moreover, it was found that the R2-dose sensitivity dependence of gel dosimeter on photon energy can vary over post irradiation; nevertheless, the R2-dose sensitivity dependence of dosimeter on dose rate dose not vary over post irradiation time.

Effect of low temperature on the aging characteristics of a potato starch gel

In this work, the freezing curve of a potato starch gel with different concentrations was determined. The water migration, texture, microstructure and gelatinization of a potato starch gel with 8% starch concentration were studied during aging. The results showed that the freezing characteristics of the potato starch gel with different starch concentrations were quite different. NMR results showed that the relaxation time and proportion of water with different existing states (T21, T22 and T23) in the potato starch gel varied significantly under different aging temperatures. Under different aging temperatures, the texture characteristics and the gel strength of the starch gel were significantly different. The water retention of the gel was better under aging temperatures of 3 °C and −3 °C than for other gel samples. SEM and C-cell results showed that under aging temperatures of 3 °C and 0 °C, the formation of a gel network structure was accelerated, and the gel was relatively firm, with small and uniform pores and a larger pore area and number. The rapid viscosity analysis results showed that the peak viscosity, breakdown and setback of the vacuum freeze-dried gel powder changed differently under the aging temperatures.

SANS and X-ray studies of the structural transitions in impurity-helium gel samples

This article presents the results of SANS studies on the structure of nanocluster impurity gel samples, and X-ray observations of the structural transformations in amorphous powders obtained during the decay of heated gel samples. The possibilities of using these methods to determine the state and structural transitions of these substances are discussed.

The dose enhancement of MAGAT gel dosimeter doped with zinc oxide at 6 MV photon beam

The cancer treatment modalities have been developed rapidly with the aim to maximize the absorbed dose toward the cancer cells while sparing the healthy tissues. The use of high atomic number, Z nanomaterials has become interest as it offers the possibilities such as destroying cancer tumor with minimal damage to the healthy tissues. The study aimed to evaluate the role of methylene blue as it reduced the self-polymerization as well as to measure the dose enhancement effect of Zinc Oxide in MAGAT gel dosimeter. The MAGAT gel formulation is composed of 5% gelatin, 6% methacrylic acid, 10 mM THPC, 5 mg/ml of zinc oxide at different sizes of 20 nm, 40 nm and 60 nm, 0.01% of methylene blue and 89% of de-ionised water. The gel samples are irradiated at 1 Gy, 3 Gy, 5 Gy, 7 Gy, 9 Gy and 10 Gy by using 6 MV photon beam. The dose response and sensitivity of MAGAT gel doped with MB and zinc oxide is obtained from the UV–Vis absorbance. The results show that the presence of methylene blue inhibit the self-polymerization problem and the addition of zinc oxide NPs increased the dose response of MAGAT gel dosimeter. This new gel formulation showing a promising polymer gel dosimeter with an increase in radiation effectiveness.

Effects of molecular weight distribution of soluble microbial products (SMPs) on membrane fouling in a membrane bioreactor (MBR): Novel mechanistic insights

While molecular weight distribution (MWD) is one of the most important properties of soluble microbial products (SMPs), mechanisms underlying effects of MWD of SMPs on membrane fouling have not well unveiled. In this study, it was found that, the supernatant of sludge suspension in a membrane bioreactor (MBR) for wastewater treatment can be fractionated into a series of SMPs samples with different molecular weight (MW) fraction. The real gel sample mainly formed by the rejected SMPs on membrane surface had a high specific filtration resistance (SFR) of 1.21 × 1016 m−1 kg−1. The SFR of SMPs samples and the model foulants of polyethylene glycol (PEG) increased with their MW. The change trend of SFR with MW cannot be sufficiently explained by three-dimensional excitation-emission matrix (EMM) and chemical compositions. Tyndall effect analysis indicated that gelating ability of SMPs and PEG in the solution increased with their MW. Scanning electron microscope (SEM) confirmed gel structure changes with the PEG MW. Accordingly, mechanisms based on Carman–Kozeny equation and Flory–Huggins lattice theory were proposed to interpret SFR of SMPs with low and high MW, respectively. Simulating these two mechanistic models on PEG samples resulted in the comparable SFR data to the experimental ones, indicating the correctness and feasibility of the proposed mechanisms. The proposed mechanisms provided in-depth understanding of membrane fouling regarding MW, facilitating to develop effective membrane fouling mitigation strategies.