The effect of pretreatment on the enzymic hydrolysis of cellulosic industrial waste

The enzymic hydrolysis of cellulosic waste material from industrial origins using commercial Tricoderma viride cellulase gave yields approaching 80% conversion following pretreatments. The yield was a function of the purity of the substrate and the pretreatments imposed. These included sterilisation, heating, ball-milling and alkali treatment. Highest yields of glucose or enzyme hydrolysis were achieved with a 4% solka floc suspension following pretreatment in 5% alkali, when the enzyme mix was 0.22IU cm^?3 of filter paper activity, 0.07IU cm^?3C_x enzyme activity and 0.14IU cm^?3 of β-glucosidase activity. Kraft pulp also gave up to 75% yields by this method.     

Quality Characterization of the Olive Oil from Var. Tosca 07® Grown in a Commercial High Density Orchard

A high density olive orchard represents a new planting system that requires cultivars with low vegetative vigor, such as Arbequina and Arbosana varieties. Different cultivars provide different performances in such orchards. This research was performed in order to determine the behavior of the new olive variety Tosca 07^® in a commercial, high density orchard. The quality of Tosca 07^® olive oils in three different maturity degrees during two crops seasons by physico-chemical and nutritional characterization were compared with Arbequina olive oils obtained from trees grown under the same conditions. Tosca 07^® is a very interesting olive variety for high density orchards. Because of its early ripening, it would be suitable for early harvesting, and this could be interesting for avoiding cold temperatures, frost, etc. Tosca 07^® olive oils have also demonstrated a very suitable chemical composition in comparison with Arbequina olive oils, especially for their high content of antioxidant compounds (α-tocopherol and pigments) present within the oils.     

The removal of natural organic matter from selected Turkish source waters using magnetic ion exchange resin (MIEX®)

The primary objective of this work was to evaluate the effectiveness of the MIEX^® process in removing natural organic matter (NOM) from selected drinking water sources of the City of Istanbul. Raw water samples from five drinking water treatment plants (Elmalı, B.Çekmece, Ömerli, İkitelli, and Kağıthane) serving to about 10 million people were collected and jar-tested in laboratory. The kinetics of NOM removal at various MIEX^® dose and contact times, the extent of resin saturation in multiple-loading experiments, and the impacts of MIEX^® pretreatment prior to coagulation on coagulant demands were investigated. After a resin dose of 5–10 ml settled resin/l and contact time of 10–20 min, dissolved organic carbon (DOC) concentrations and specific UV absorbance (SUVA₂₅₄) values obtained for all waters were <1.5 mg/l and <2 l/mg DOC-m, respectively. In addition, for all waters, 17–42% nitrate and 9–24% sulfate removals were obtained at a resin dose and contact time of 10 ml settled resin/l and 10 min, respectively. UV₂₅₄ absorbance reductions up to 96% were achieved. Increasing MIEX^® dose generally decreased the SUVA₂₅₄ values indicating that the MIEX^® resin preferentially removed UV absorbing fractions of NOM. Although some degree of initial resin saturation occurred in two raw waters up to 900 bed volume (BV) loadings, such saturations were not continuous up to 2000 BV loadings. The initial saturation was not observed for the other three waters, suggesting that MIEX^® resin can be loaded up to 2000 BVs or more (not tested) without any saturation. Depending on the raw water, the application of MIEX^® as a pretreatment prior to coagulation reduced the coagulant (alum) demand by 0–30 mg/l compared to the coagulation only. Results from the laboratory experiments overall indicated that MIEX^® resin even at relatively low dose and short contact time effectively removes NOM in all tested raw waters and reduces coagulant demands.     

The Evolution of an Amine Dehydrogenase Biocatalyst for the Asymmetric Production of Chiral Amines

The reductive amination of ketones to produce chiral amines is an important transformation in the production of pharmaceutical intermediates. Therefore, industrially applicable enzymatic methods that enable the selective synthesis of chiral amines could be very useful. Using a phenylalanine dehydrogenase scaffold devoid of amine dehydrogenase activity, a robust amine dehydrogenase has been evolved with a single two‐site library allowing for the direct production of (R)‐1‐(4‐fluorophenyl)‐propyl‐2‐amine from para‐fluorophenylacetone with a k_cat value of 6.85 s⁻¹ and a K_M value of 7.75 mM for the ketone substrate. This is the first example of a highly active amine dehydrogenase capable of accepting aliphatic and benzylic ketone substrates. The stereoselectivity of the evolved amine dehydrogenase was very high (>99.8% ee) showing that high selectivity of the wild‐type phenylalanine dehydrogenase was conserved in the evolution process. When paired with glucose/glucose dehydrogenase, NADH cofactor can be effficiently regenerated and the reaction driven to over 93% conversion. The broad specificity, high selectivity, and near complete conversion render this amine dehydrogenase an attractive target for further evolution toward pharmaceutical compounds and subsequent application.     

The effect of copolymer composition on the surface properties of perfluoroalkylethyl acrylates

The surface properties of two perfluoroalkylethyl acrylic copolymers—aqueous, Zonyl^®329 and solvent‐based, Zonyl^®225—were studied. Zonyl^®329 is a water‐based dispersion and Zonyl^®225 a solvent‐based copolymer solution; both polymers have the same perfluoroalkyethyl side chains [F(CF₂)_nCH₂CH₂? ] but have different comonomer compositions. Thin films, prepared by dip coating onto mica and quartz, with and without annealing, were characterized by contact angle and by X‐ray photoelectron spectroscopy (XPS). The contact angle measurements showed little variation with polymer and with substrate, consistent with the supposition that the perfluoroalkylethyl chains aggregate on the surface and thus dominate surface properties, irrespective of the composition of the rest of the polymer. XPS revealed only small variations in surface chemistry for studied films. Annealed films showed improved segregation for solvent‐based Zonyl^®225, which has both hydrocarbon alkyl and perfluoroalkylethyl side chains; the presence of hydrocarbon alkyl chains enables the perfluoroalkylethyl chains to reorganize after annealing. Depending on the external conditions, this thermal treatment can enable more perfluoroalkylethyl chains to reach the film surface (solid/air interface), leading to a reduction in the dispersive‐dominant surface and enhancement in perfluoroalkylethyl segregation. This suggested that perfluoroalkylethyl side chains dominate the surface properties, which are thus not dependent on substrate, backbone composition, or formulation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Developing Ways of Obtaining Quality Hydrolyzates Based on Integrating Catalytic Peroxide Delignification and the Acid Hydrolysis of Birch Wood

Traditional processes of acid-catalyzed hydrolysis of wood are ineffective due to the low quality of formed glucose solutions contaminated with impurities that inhibit fermentation of glucose to ethanol. This problem grows during the hydrolysis of birch wood containing large amounts of hemicellulose. This work proposes producing quality glucose solutions using sulfuric acid (H₂SO₄, 80%) catalyzed hydrolysis at 25°C the cellulosic products formed during the catalytic peroxide delignification of birch wood. It is established that the composition of cellulosic products strongly affects the contents of glucose, xylose, and impurities inhibiting the enzymatic synthesis of bioethanol: furfural, 5-hydroxymethyl furfural, and levulinic acid. High yields (80.4–83.5 wt %) of glucose are achieved using cellulosic products produced by integrating the processes of sulfuric acid hydrolysis of hemicelluloses from birch wood and peroxide delignification of prehydrolyzed wood in the presence of catalysts: 2% H₂SO₄ and 1% TiO₂. Concentration of inhibitors of enzymatic processes in these hydrolyzates is below the allowable limits. Hydrolyzates with maximum glucose content (86.4–88.5 wt %) and minimum concentration of inhibiting impurities produced by acid hydrolysis of cellulosic products treated with an 18% solution of NaOH. Gas chromatography, HPLC, and chromato-mass spectrometry are used to analyze the composition of hydrolyzates. Cellulosic products are examined by SEM, XRD, and chemical analysis.     

An approach to optimization of enzymatic hydrolysis from sugarcane bagasse based on organosolv pretreatment

BACKGROUND: The organosolv pretreatment followed by enzymatic hydrolysis of the pretreated material and subsequent fermentation of the hydrolysate produced, was the strategy used for ethanol production from sugarcane bagasse. The effect of different operational variables affecting the pretreatment (the catalyst type and its concentration, and the pretreatment time) and enzymatic hydrolysis stage (substrate concentration, cellulase loading, addition of xylanase and Tween 20, and the cellulase/β‐glucosidase ratio), were investigated. RESULTS: The best values of glucose concentration (28.8 g L^?1) and yield (25.1 g per 100 g dry matter) were obtained when the material was pretreated with 1.25% (w/w) H₂SO₄ for 60 min, and subsequently hydrolyzed using 10% (w/v) substrate concentration in a reaction medium supplemented with xylanase (300 UI g^?1) and Tween 20 (2.5% w/w). Fermentation of the broth obtained under these optimum conditions by Saccharomyces cerevisiae resulted in an ethanol yield of 92.8% based on the theoretical yield, after 24 h. CONCLUSION: Organosolv pretreatment of sugarcane bagasse under soft conditions, and subsequent enzymatic hydrolysis of the pretreated material with a cellulolytic system supplemented with xylanase and Tween 20, is a suitable procedure to obtain a glucose rich hydrolysate efficiently fermentable to ethanol by Sacharomyces cerevisiae yeasts. Copyright © 2010 Society of Chemical Industry     

Hydrothermal conversion of glucose in multiscale batch processes. Analysis of the gas,liquid and solid residues

Hydrothermal conversion is an interesting process to transform (very) humid biomass into high energy vectors or valuable products in the liquid or solid state. In the supercritical domain, water becomes a solvent for organics as well as a reactant, and thus the cellulosic content is effectively hydrolyzed into glucose, largely considered as its model molecule.The kinetics of glucose decomposition during the heating step in the batch reactor were investigated through the analysis of glucose concentration. Glucose reacts totally before reaching the supercritical point of water. Among the operating parameters that influence supercritical water gasification, this paper presents only the effect of reaction temperature through gas composition, liquid carbon content and structure of the solid. Glucose gasification in a batch process (5 wt% glucose, 0.5 wt% catalyst, 600 °C, 25 MPa, 60 min) produced 1.5 mol of hydrogen per mol of glucose. The gas has energetic properties (H₂, CH₄, C₂H₆) while the liquid contains substances that could be used as platform molecules (5-HMF). The solid phase is composed of carbon (almost pure) in two distinct phases: spherical nanoparticles and an amorphous phase.     

Enzymatic saccharification of dissolution pretreated waste cellulosic fabrics for bacterial cellulose production by Gluconacetobacter xylinus

BACKGROUND: Waste textiles, such as dyed cellulosic and/or polyester blended fabrics have the potential to serve as an alternative feedstock for the production of biological products via microbial fermentation. Dissolution pretreatment was employed to enhance the enzymatic saccharification of dyed and synthetic fiber blended cellulosic fabrics. The fermentable reducing sugars obtained from waste cellulosic fabrics were used to culture Gluconobacter xylinus for value‐added bacterial cellulose (BC) production. RESULTS: Concentrated phosphoric acid was the ultimate cellulose solvent for dissolution pretreatment since 5% w/w cellulosic fabric can be completed dissolved at 50 °C. After regeneration in water, the cellulosic precipitate was subjected to cellulase hydrolysis, resulting in at least 4‐fold enhancement of saccharification rate and reducing sugars yield. The colored saccharification products can be utilized by G. xylinus to produce BC, approximately 1.8 g L^?1 BC pellicle was obtained after 7 days static cultivation. CONCLUSION: Dyed and blended waste fabric can be pretreated effectively by dissolution to produce fermentable sugars by cellulase hydrolysis. Dissolution pretreatment can expose the dyed or polyester fiber covered digestible cellulosic fibers to cellulase and leads to a significant enhancement of saccharification yield. The colored saccharification products have no significant inhibiting effect on the fermentation activity of G. xylinus for BC production. Copyright © 2010 Society of Chemical Industry     

Understanding the Rate‐Limiting Step of Glycogenolysis by Using QM/MM Calculations on Human Glycogen Phosphorylase

Liver glycogen phosphorylase (GP) is a key enzyme for human health, as its increased activity is associated with type 2 diabetes. The GP catalytic mechanism has been explored by quantum mechanics/molecular mechanics (QM/MM) methods. Herein, we propose a mechanism that proceeds by three steps: 1) it begins with transfer of a hydrogen atom from the phosphate group of the pyridoxal 5′‐phosphate (HPO₄^2?‐PLP) cofactor to the phosphate substrate; 2) the glycosidic linkage is then cleaved through protonation of the glycosidic oxygen atom by a hydroxy group of the inorganic phosphate group; and 3) an oxygen atom of the phosphate performs a nucleophilic attack on the anomeric carbon atom of glucose, concomitant with the return of a proton from phosphate to PO₄^3?‐PLP, which finally leads to formation of the glucose‐1‐phosphate product and recovers the initial state of the PLP cofactor. The glycosidic bond cleavage and nucleophilic attack from the phosphate group to the glycosyl molecule have the highest activation free energies. The structural properties of the hereby characterized transition states could be very useful in structure‐based drug design studies against liver GP.     

Phospholipase D Activity in Relation to the Size of Substrate Micelles

The activity of phospholipase D (PLD) is strongly dependent on the aggregation state of its substrate. Artificial substrates, such as phosphatidyl‐p‐nitrophenol (PpNP), are preferably used in a mixture with Triton^® X‐100 (Serva) and sodium dodecyl sulfate (SDS) in the form of mixed micelles. In this paper the activities of PLD from cabbage (PLD_cab), which needs Ca²⁺ ions for its activity, and PLD from Streptomyces sp. (PLD_Str), which is independent of Ca²⁺ ions, are compared as a function of the detergent and substrate concentrations. While the variation of the Triton^® X‐100 and PpNP contents changed the activities of both enzymes in similar way, SDS showed activation effects on plant PLD but inactivation effects on microbial PLD. The activity decreased to 50% at a 7‐tenfold molar excess of Triton^® X‐100 related to PpNP. SDS induced a strong activation (up to fourfold) of PLD_cab but decreased the activity of PLD_Str with increasing concentration. Activity‐substrate profiles of both PLDs passed optima at 3–4 mM PpNP. In all experiments, the activity changes correlated with changes of the micelle sizes determined by dynamic light scattering. These results highlight the immense importance of the micelle structure, which is not considered in most studies.     

Transesterification of triacetin with methanol on Nafion® acid resins

Although homogeneous alkali catalysts (e.g., NaOH) are commonly used to produce biodiesel by transesterification of triglycerides (vegetable oils and animal fats) and methanol, solid acid catalysts, such as acidic resins, are attractive alternatives because they are easy to separate and recover from the product mixture and also show significant activity in the presence of fatty acid impurities, which are common in low-cost feedstocks. To better understand solid acid catalyst performance, a fundamental transesterification kinetic study was carried out using triacetin and methanol on Nafion^® (perfluorinated-based ion-exchange resin) catalysts. In particular, Nafion^® SAC-13 (silica-supported Nafion) and Nafion^® NR50 (unsupported Nafion) were investigated, because both show great promise for biodiesel-forming reactions. The reaction kinetics for a common homogeneous acid catalyst (H₂SO₄) were also determined for comparison. Liquid-phase reaction was performed at 60 °C using a stirred batch reactor. The swelling properties of the resin in solvents of diverse polarity that reflect solutions typically present in a biodiesel synthesis mixture were examined. The initial reaction rate was greatly affected by the extent of swelling of the resin, where, as expected, a greater effect was observed for Nafion^® NR50 than for the highly dispersed Nafion^® SAC-13. The reaction orders for triacetin and methanol on Nafion^® SAC-13 were 0.90 and 0.88, respectively, similar to the reaction orders determined for H₂SO₄ (1.02 and 1.00, respectively). The apparent activation energy for the conversion of triacetin to diacetin was 48.5 kJ/mol for Nafion^® SAC-13, comparable to that for H₂SO₄ (46.1 kJ/mol). Selective poisoning of the Brønsted acid sites on Nafion^® SAC-13 using pyridine before transesterification revealed that only one site was involved in the rate-limiting step. These results suggest that reaction catalyzed by the ion-exchange resin can be considered to follow a mechanism similar to that of the homogeneous catalyzed one, where protonated triglyceride (on the catalyst surface) reaction with methanol is the rate-limiting step.     

Continuous production of biosurfactant with foam fractionation

A glucose‐limited chemostat was used to determine the growth parameters of BBK006 for continuous production of the biosurfactant surfactin. The continuous cultivation exhibited low maintenance metabolism (m = 0.39 mmol_glucose g_bacteria^?1 h^?1) and high molar growth yield ( g_bacteria mol_glucose^?1). It was found that the surfactin production rate in continuous culture was not only a function of dilution rate but also varied with the initial concentration of glucose in the feed. A high steady state concentration of surfactin (18 mg L^?1) was maintained in the culture at a dilution rate of 0.2 h^?1 when glucose concentration in the feed was 0.25 g L^?1. This is the first demonstration of continuous surfactin production and recovery using glucose as a carbon source. The production of surfactin is known to be related to the age of the microorganisms and a simple mathematical model has been constructed to show how the age‐related production can be quantified. Copyright © 2006 Society of Chemical Industry     

Metal‐Fluorocarbon Pyrolants. XIII: High Performance Infrared Decoy Flare Compositions Based on MgB2 and Mg2Si and Polytetrafluoroethylene/Viton®

In the presented work two experimental pyrolants for use in blackbody infrared decoy flares showing higher performance than baseline magnesium/polytetrafluoroethylene/Viton® ( MTV ) were investigated. These pyrolants are based on fuels hitherto unknown to pyrotechnics: magnesium diboride, MgB₂, and dimagnesium silicide, Mg₂Si. Both fuels were formulated with polytetrafluoroethylene, PTFE and a fluorocarbon binder Viton® (designated MbTV and MsTV ). MsTV yields higher radiance, L_λ (W cm⁻² sr⁻¹) in the mid infrared range (2–5 μm) than MTV at same stoichiometry. The volumetric spectral efficiency E_λ (J cm⁻³ sr⁻¹) of MbTV is also superior to MTV. MbTV thus allows for size reduction of black body countermeasure flares and thereby has potential to enhance the survivability of aircraft in hostile environments. Due to its very high burning rate MsTV qualifies for first fire and igniter applications.     

NO and N2O emissions from savanna soils following the first simulated rains of the season

Data on the emissions of oxides of nitrogen from the soil during the early part of the wet season are reported for nutrient-rich and nutrient-poor sandy soils at Nylsvley, South Africa. The emissions of NO_x and N₂O following the first wetting event of the season are elevated relative to subsequent events. The observed high emission rates (76 ng N-NO m^-2 s^-1) are partially attributed to the sandiness of the soil, which permits NO to diffuse out of the soil rapidly. The pulse of high emissions following wetting is maintained for approximately 72 hours, thereafter continuing at around 20 ng NO m^-2 s^-1 while the soil remains moist. The initial pulse is suggested to be due to the accumulation of a substrate pool during the dry period, coupled with an inability of plants and microbes to use it effectively during the first few days after wetting. There were no significant differences in the peak or subsequent emission rates for either NO or N₂O between two sites of differing nitrogen mineralisation potentials. N₂O emissions averaged 8% of NO_x emissions. The enhanced emissions of NO_x which follow the first wetting after a prolonged dry period do not make a very large contribution to the annual gaseous N emission budget, but could be a significant contributor to the high tropospheric ozone levels observed over southern Africa in springtime.     

Partial masking of cellulosic fiber hydrophilicity for composite applications. Water sorption by chemically modified fibers

Cotton cellulosic fibers have been treated with alkyl isocyanates, modified polypropylene or other aliphatic agents in more or less swelling mediums. Their hydrophilicity can be reduced and this effect is studied by the associated techniques of microgravimetry and microcalorimetry. For the non-treated sample, a sorption mechanism is proposed: two water molecules linked by a double H bond are sorbed per amorphous glucose unit with a high molar energy (–65 to –58 kJ/mol⁻¹) up to P/P_o = 0.85. Above this pressure, the water is sorbed with the liquefaction molar energy (–44 kJ/mol⁻¹). For the treated fibers, the two preceding stages are always observed as a function of P/P_o, but interesting results are obtained for alkyl isocyanate modified samples, with varying lengths of the alkyl chains: C₃H₇₋, C₈H₁₇₋ or C₁₈H₃₇₋. These results show the importance of a critical length of the alkyl chain (between three and eight carbons) for reducing the amount of sorbed water by 25% and modifying the mean diffusion coefficient. These effects would be due to the blocking by the linked agents of some water diffusion paths. © 1996 John Wiley & Sons, Inc.     

Water vapor and CO2 transport through amine-containing facilitated transport membranes

Amine-containing CO₂ facilitated transport membranes have great potential to be applied for hydrogen purification from synthesis gas. In some applications, the humidity of the retentate stream is required as well as the purity of hydrogen. The membranes are highly hydrophilic, and they exhibit not only high CO₂ permeance but also high water vapor permeance. In this work, the transport of water vapor and CO₂ through the membranes composed of an amine-containing selective layer and a microporous polysulfone substrate was investigated. From the experiments conducted, water vapor permeance appeared to be independent of the selective layer thickness, indicating that the substrate is the controlling factor of the mass transfer resistance to water vapor transport. Moreover, water vapor permeance appeared to reduce linearly with increasing the number of the substrate layers. But, CO₂ permeance and CO₂/H₂ selectivity did not change significantly as the number of the substrate layers increased. These results indicated that the CO₂ separation performance is governed by the selective layer as expected. In addition, the membranes synthesized from Lupamin^® containing 34% polyvinylamine and 66% salt (sodium formate) demonstrated better CO₂ separation performance than those from pure polyvinylamine, presumably due to better water retention capability of the salt than polyvinylamine.     

Impact of H+ ion beam irradiation on Matrimid®. II. Evolution in gas transport properties

Ion beam irradiation is an easily controlled method to modify the chemical structure and microstructure of polymers including the fractional free volume, free volume distribution and chain mobility, thus altering the gas transport properties of the irradiated polymers. The previous paper focused on the impact of H⁺ ion beam irradiation on chemical structural evolution of the polyimide Matrimid®. This paper focuses on the impact of H⁺ ion beam irradiation on microstructure and gas permeation properties of Matrimid®. Irradiation at low ion fluence resulted in slight decreases in permeabilities for five gases (i.e., He, CO₂, O₂, N₂, and CH₄) with increases in permselectivities for some gas pairs (e.g., He/CH₄ and He/N₂). In contrast, irradiation at relatively high ion fluences resulted in simultaneous increases in permeabilities and permselectivities for most gas pairs (e.g., He/CH₄, He/N₂, O₂/N₂, and CO₂/CH₄). While Matrimid® has bulk gas permeation properties that are below the range of commercially interesting polymers, samples irradiated at high ion fluences exhibited significant improvement in gas separation performances. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1670–1680, 2007     

Enzymatic saccharification of lignocellulosic materials after treatment with supercritical carbon dioxide

Lignocellulosic materials, such as agricultural residues, are abundant renewable resources for bioconversion to sugars. The sugar cane bagasse was studied here to obtain simple sugars for the production of alcohols and other chemicals. The crystalline structure of cellulose and the lignin that physically seals the surrounding cellulose fibers makes enzymatic hydrolysis difficult by preventing the contact between the cellulose and the enzyme. Two different samples of sugar cane (bagasse pulp and skin) were used and compared with microcrystalline cellulose (Avicel). The investigated samples were pretreated with SC-CO₂ explosion before hydrolysis. The experiments were conducted at 12, 14 and 16 MPa at a temperature of 60 °C. In this process, particles of celluloses within the size range from 0.25 to 0.42 mm were placed in defined amounts inside the experimental vessel, CO₂ was injected and let stand for 5 and 60 min. The explosion pretreatment of cellulosic materials by SC-CO₂ was performed in an apparatus of a static type with 300 ml of volume. The hydrolysis reaction using cellulose enzyme was carried at 55 °C for 8 h. After the pretreatment, the glucose yield increased in 72% to the bagasse sample. The SC-CO₂ pretreatment together with alkali increased the glucose yield in 20% as compared with alkali only. X-ray, microscopy and thermal analysis were used to investigate the effect of the pretreatment.     

Hydrophobic SiO2 nanoparticle-induced polyvinylidene fluoride crystal phase inversion to enhance permeability of thin film composite membrane

Thin film composite (TFC) membrane can get rid of small molecular contaminants and salts with a very high efficiency, thus exhibiting promising potential for addressing the emerging problem of a clean water shortage. In this work, a new type of TFC membrane was prepared by interfacial polymerization of two monomers (MPD and TMC) on surface of SiO₂/polyvinylidene fluoride (PVDF) substrate. The maximum flux of 3.16 L m⁻² h⁻¹ Bar⁻¹ was achieved for the optimized hydrophobic SiO₂ nanoparticles well dispersed in PVDF substrate, which is 2.6 times higher than that of 1.21 L m⁻² h⁻¹ Bar⁻¹ for the commercial cellulose triacetate reverse osmosis membrane. The improved performance of TFC membrane could be attributed to the higher compaction resistance of SiO₂/PVDF substrate. Further analysis revealed that PVDF crystal phase inversion induced by superhydrophobic SiO₂ nanoparticles obviously enhanced the intramolecular and intermolecular hydrogen bonds between PVDF polymer molecules. Additionally, the narrower finger-like pore size and thicker pore wall of SiO₂/PVDF substrate also played significant roles in enhancing the compaction resistance of PVDF membrane. This work also provides a proof-of-concept demonstration of high permeability substrates for effective flux enhancement of TFC membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48204.