Silica Sponge Research Articles

Silica-associated proteins from hexactinellid sponges support an alternative evolutionary scenario for biomineralization in Porifera

Metazoans use silicon traces but rarely develop extensive silica skeletons, except for the early-diverging lineage of sponges. The mechanisms underlying metazoan silicification remain incompletely understood, despite significant biotechnological and evolutionary implications. Here, the characterization of two proteins identified from hexactinellid sponge silica, hexaxilin and perisilin, supports that the three classes of siliceous sponges (Hexactinellida, Demospongiae, and Homoscleromorpha) use independent protein machineries to build their skeletons, which become non-homologous structures. Hexaxilin forms the axial filament to intracellularly pattern the main symmetry of the skeletal parts, while perisilin appears to operate in their thickening, guiding extracellular deposition of peripheral silica, as does glassin, a previously characterized hexactinellid silicifying protein. Distant hexaxilin homologs occur in some bilaterians with siliceous parts, suggesting putative conserved silicifying activity along metazoan evolution. The findings also support that ancestral Porifera were non-skeletonized, acquiring silica skeletons only after diverging into major classes, what reconciles molecular-clock dating and the fossil record.

Nudibranch predation boosts sponge silicon cycling

Diatoms play a key role in the marine silica cycle, but recent studies have shown that sponges can also have an important effect on this dynamic. They accumulate large stocks of biogenic silica within their bodies over long periods, which are thought to vary little on an intra-annual scale. The observation of an abrupt decline in sponge biomass in parallel with large increases in abundance of a spongivorous nudibranch (Doris verrucosa) led us to conduct a year-long study on the effect of nudibranch predation on the silicon budget of a sponge (Hymeniacidon perlevis) population. After 5 months of predation, the abundance of sponge individuals did not change but their biomass decreased by 95%, of which 48% was explained by nudibranch predation. About 97% of sponge spicules ingested by nudibranchs while feeding was excreted, most of them unbroken, implying a high rate of sponge silica deposition in the surrounding sediments. After predation, sponges partially recovered their biomass stocks within 7 months. This involved a rapid growth rate and large assimilation of dissolved silicon. Surprisingly, the highest rates of silicon absorption occurred when dissolved silicon concentration in seawater was minimal (< 1.5 µM). These findings suggest that the annual sponge predation-recovery cycle triggers unprecedented intra-annual changes in sponge silicon stocks and boosts the cycling of this nutrient. They also highlight the need for intra-annual data collection to understand the dynamics and resilience of sponge ecosystem functioning.

On the dissolution of sponge silica: Assessing variability and biogeochemical implications

The dissolution of the biogenic silica that constitutes the skeletons of silicifying organisms is an important mechanism for regenerating dissolved silicon in the ocean. The silica skeletons deposited to the seafloor after the organisms die keep dissolving until becoming definitively buried. The low dissolution rate of sponge skeletons compared to that of diatom skeletons favors their burial and makes sponges (Phylum Porifera) to function as important silicon sinks in the oceans. However, it remains poorly understood whether the large variety of siliceous skeletons existing in the Porifera involves similar variability in their dissolution rates, which would affect the general conceptualization of these organisms as silicon sinks. Herein we investigated kinetics of silica dissolution for major types of skeletons in the three siliceous lineages of Porifera, following standardized digestion conditions in 1% sodium carbonate with orbital agitation at 85°C. The results are compared with those of a previous study conducted under identical conditions, which considered diatom silica, sponge silica, and lithogenic silica. Unexpectedly, the silica of homoscleromorph sponges dissolved only a bit slower than that of freshly cultured diatoms and as fast as diatom earth. However, the rest of sponge skeletons were far more resistant, although with some differences: the isolated spicules of hexactinellid sponges dissolved slightly faster than when forming frameworks of fused spicules, being hexactinellid frameworks as resistant to dissolution as the silica of demosponges, irrespective of occurring in the form of isolated spicules or frameworks. The experiments also indicated that the complexation of sponge silica with aluminum and with chitin does not increase its resistance to dissolution. Because the rapidly-dissolving homoscleromorph sponges represent less than 1% of extant sponges, the sponge skeletons are still conceptualized as important silicon sinks due to their comparative resistance to dissolution. Yet, the turnover of silica into dissolved silicon will always be faster in environments dominated by hexactinellids with isolated spicules than in environments dominated by other hexactinellids and/or demosponges. We discuss whether the time required for a given silica type to completely dissolve in 1% sodium carbonate could be a predictor of its preservation ratio in marine sediments.

High-capacity adsorbents from stainless steel slag for the control of dye pollutants in water

Adsorbent materials for the control of dye pollutants in water were synthetized from stainless steel slag (SSS) using different acid-base treatments. Using HCl (SS-Cl) and HNO3 (SS-NO3) produced high-capacity adsorbents, with BET areas of 232 m2/g and 110 m2/g respectively. Specifically, the SS-Cl had a structure of amorphous silica sponge. Treatment with H2SO4 (SS-SO4) did not enhance the adsorption capabilities with respect to the raw sample (SSS). Activated carbon (AC) was also tested as reference. The materials were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 adsorption-desorption isotherms, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) zeta potential, and infrared spectroscopy (FTIR). Batch adsorption experiments with methylene blue (MB) showed that the maximum sorption capacities were 9.35 mg/g and 8.97 mg/g for SS-Cl and SS-NO3 at 240 h, respectively. These values, even at slower rate, were close to the adsorption capacity of the AC (9.72 mg/g). This behavior has been attributed to the high porosity in the range of nanopores (0.6–300 nm) and the high-surface area for both samples. Preferential involvement of certain functional groups in the adsorption of dye ions on their surface indicative of chemisorption has been found. Although optimization, repeatability, and reproducibility of the process and environmental assessment have to be done before practical applications, these preliminary results indicate that application of these cost-effective adsorbents from raw SSS may be used in water pollution treatment and contribute to the sustainable development of the steel manufacturing industry.

Recycling resources: silica of diatom frustules as a source for spicule building in Antarctic siliceous demosponges

Abstract Dissolved silicon (DSi) is biologically processed to produce siliceous skeletons by a variety of organisms including radiolarians, silicoflagellates, choanoflagellates, plants, diatoms and some animals. In the photic ocean, diatoms are dominant consumers over competing other silicifiers. In Antarctica, where DSi is not particularly limiting, diatoms and sponges coexist in high abundances. Interestingly, diatom ingestion by sponges is a regular feeding strategy there. Although it was known that the diatom organic nutrients are readily metabolized by the sponges, what happened to the inorganic diatom silica skeleton remained unexplored. Here, we have conducted a multi-analytical approach to investigate the processing of diatom silica and whether it is reconverted into sponge silica. We have documented widespread diatom consumption by several demosponges, identifying storage vesicles for the diatom-derived silica by electron microscopy and microanalysis. Diatom-consuming sponges showed upregulation of silicatein and silicase genes, which in addition to the δ 30Si values of their silica, supports that the sponges are converting the ingested diatom silica into sponge silica without much further Si fractionation. Our multidisciplinary approach suggests that the reutilization of diatom silica by sponges is a common feature among Antarctic sponges, which should be further investigated in other latitudes and in other silicifiers.

Mid-Furongian trilobites and agnostids from theWujiajiania lyndasmithaeSubzone of theElviniaZone, McKay Group, southeastern British Columbia, Canada

AbstractA well-preserved fauna of largely articulated trilobites is described from three new localities close to one another in the Bull River Valley, southeastern British Columbia. All the trilobites from these localities are from the lower or middle part of theWujiajiania lyndasmithaeSubzone of theElviniaZone, lower Jiangshanian, in the McKay Group. Two new species are proposed with types from these localities:Aciculolenus askewiandCliffia nicoleae. The trilobite (and agnostid) fauna from these localities includes at least 20 species:Aciculolenus askewin. sp.,Agnostotes orientalis(Kobayashi, 1935),Cernuolimbus ludvigseniChatterton and Gibb, 2016,Cliffia nicoleaen. sp.,Elvinia roemeri(Shumard, 1861),Grandagnostus? species 1 of Chatterton and Gibb, 2016,Eugonocare?phillipiChatterton and Gibb, 2016,Eugonocare? sp. A,Housia vacuna(Walcott, 1912),Irvingella convexa(Kobayashi, 1935),Irvingella flohriResser, 1942,Irvingellaspecies B Chatterton and Gibb, 2016,Olenaspella chrisnewiChatterton and Gibb, 2016,Proceratopyge canadensis(Chatterton and Ludvigsen, 1998),Proceratopyge rectispinata(Troedsson, 1937),Pseudagnostuscf.P. josepha(Hall, 1863),Pseudagnostus securiger(Lake, 1906),Pseudeugonocare bispinatum(Kobayashi, 1962),Pterocephaliasp., andWujiajiania lyndasmithaeChatterton and Gibb, 2016.Pseudagnostus securiger, a widespread early Jiangshanian species, has not been previously recorded from southeastern British Columbia. Non-trilobite fossils collected from these localities include brachiopods, rare trace fossils, a complete silica sponge (Hyalospongea), and a dendroid graptolite. The faunas from these localities are more diverse and better preserved than those from other previously documented localities of the same age in the region.Additional specimens of a rare species, found by amateur collectors in previously documented localities of slightly younger age (upper part ofWujiajiania lyndasmithaeSubzone) in the same region, are documented. These new specimens, when combined with an earlier discovered specimen, provide adequate type material to propose a new species ofLabiostria, L. gibbae, which may be useful for biostratigraphy.UUID:http://zoobank.org/89551eac-b3af-4b2b-8ef3-7c2e106a560d

Robust superhydrophobic fluorinated fibrous silica sponge with fire retardancy for selective oil absorption in harsh environment

Water pollution caused by oil leaks is a global environmental problem, calling for high-performance superabsorbent materials for the selective removal and recovery of oil from water. Herein, a robust fluorinated silica fibrous sponge (Silica-GA-F) was developed as an efficient superabsorber for selective oil absorption in harsh environments. Silica fibrous sponge was fabricated by self-assembly electrospinning and calcination. Superhydrophobic Silica-GA-F was obtained after crosslinking and fluorination using glutaraldehyde (GA) and perfluorodecyltriethoxysilane (PDTS). The fluffy microscale fibrous structure and low surface energy of Silica-GA-F contributed to its low bulk density of 16 mg/cm3, relatively high surface area of 6.5 m2/g, and high water contact angle of 151°. The sagging of water interface along silica fiber profile led to an impregnated Cassie-Baxter wetting sate and a “rose petal” effect. The Silica-GA-F possesses an extraordinary absorption capacity of ~122 times of its weight toward various oils, excellent separation efficiency, and promising stability in harsh environments and repetitive use. The oil absorbed can be combusted due to the fire retardancy of Silica-GA-F. Moreover, the GA crosslinking renders the silica sponge with high dimensional stability and recoverability. These properties make the Silica-GA-F sponge an ideal selective superabsorbent material with superior robustness and stability for water remediation, especially in harsh environments.

The relation of a coastal environment to early diagenetic clinoptilolite (zeolite) formation - New data from the Late Cretaceous European Basin

Clinoptilolite, an authigenic mineral of the zeolite group, is commonly considered as a product of rhyolitic volcanic glass transformation during diagenesis of carbonate pelagic/hemipelagic sediments of Cretaceous-Paleogene age. Another, subordinate way of clinoptilolite formation that has been suggested in the literature is its precipitation during diagenetic transformation of carbonate sediments enriched with biogenic silica. The observations concerning transformation of the latter into zeolite are scarce and mostly based on Cretaceous pelagic, hemipelagic and shallow marine deposits, and post-Cretaceous sediments in which there was no volcanic material. The mechanism of diagenetic clinoptilolite formation in volcanic-free sediments, as well as the role of the depositional setting in its precipitation, is not well understood. In carbonates of the NW part of the European Basin (west side of the Łysogóry-Dobrogea Archipelago) studied here, the clinoptilolite is associated with opal-CT (from the dissolution of sponge spicules) and a detrital clays are documented for the first time in a Cretaceous coastal environment. The carbonates were deposited in a coastal environment which was under the influence of weak currents delivering sponge spicules (biogenic opal) from the offshore zone and the terrestrial input was transported by rivers from a neighboring island. The lush plant vegetation, with numerous pteridophytes and conifers, within a warm (sub-tropical or tropical) and humid climate enhanced the terrestrial weathering of clays and feldspars. This unique combination of elevated silica concentrations (from sponge spicules dissolution) and aluminum availability (from terrestrial weathering of feldspars in a subtropical climate) during the early diagenesis combined with alkalinity triggered by organic matter decomposition, enhanced the clinoptilolite formation a few centimeters below the seabed. The investigation demonstrates a novel route by which pore-fluids enriched with silica and aluminum initiate clinoptilolite formation during the very early stage of diagenesis, a few centimeters below the seafloor. The clinoptilolite distribution in Late Cretaceous silica rich deposits (with no volcanic input) of the European Basin is always associated with opal-CT, from sponge spicules and elevated terrestrial input (clays). Taking into account the distinctive Campanian-Maastrichtian sedimentation in the epicontinental European Basin, composed almost exclusively of pure pelagic carbonates, the depositional settings in which the silica and aluminum were available in pore waters was restricted to the part of the basin influenced by terrestrial input. This leads to the conclusion that clinoptilolite formation in volcanic-free sediment is an indicator of not only enhanced sponge silica availability but also the close proximity of the source area.

Magnetically driven superhydrophobic silica sponge decorated with hierarchical cobalt nanoparticles for selective oil absorption and oil/water separation

Three-dimensional superhydrophobic/superoleophilic materials (3D-HOMs) with remote controllability are highly desirable for water remediation. Herein, a new monolithic silica sponge decorated with hierarchical cobalt (Co) nanoparticles that fulfils almost all major requirements and applications for water remediation was fabricated by self-assembly electrospinning, controlled particle precipitation, and subsequent surface coating. Attributing to the continuous silica fibers and the hierarchical Co microstructures, the modified silica sponge (MSS) possesses excellent superhydrophobicity and oil selectivity, low bulk density (49 mg/cm3), high surface area (8.7 m2/g) and absorption capacity (45–91-fold weight gain), ultrahigh thermal resistance (tolerance to liquid nitrogen and combustion), flexibility, deformability, durability, and remote controllability through magnetic field manipulation. Moreover, simply compacting MSS can easily enhance its separation efficiency by bringing the interior structures to the contacting interfaces, which solves the performance deterioration issue over time for most 3D-HOMs. With all of these satisfactory properties, MSSs can be used as both durable magnetic superabsorbers and efficient oil/water separation filters with a long life span.

Fabrication of fibrous silica sponges by self-assembly electrospinning and their application in tissue engineering for three-dimensional tissue regeneration

Fabrication of highly porous, three-dimensional (3D) scaffolds with biomimicking microstructures for tissue engineering has received extensive attention lately. Although several studies have used silica asa filler material in various polymeric scaffold matrices for tissue engineering, there are no reports of 3D scaffolds fabricated solely with silica. In this study, we developed a method to fabricate fibrous silica sponges using a tetraethyl orthosilicate (TEOS)/polyvinyl alcohol (PVA) solution via self- assembly electrospinning and subsequent calcination. We then evaluated its potential application in tissue engineering. A detailed mechanism study revealed that appropriate crosslinking between hydrolyzed TEOS and PVA was the key to inducing 3D fiber stacking. The prepared silica sponges had a bulk density of 16mg/cm3, a surface area of 6.45m2/g, and a porosity of 98%, which endowed them with super-high absorbability. Cell culture results with 3T3 fibroblasts confirmed that the cells interacted strongly with the 3D silica fibers, showing a higher viability and proliferation rate than on 2D silica membranes, and that the cells migrated into the inner area of the sponge rapidly, indicating these silica sponges have potential to be used for 3D tissue regeneration.

Novel polydimethylsiloxane (PDMS) composites reinforced with three-dimensional continuous silica fibers

The ultimate goal in the preparation of composite materials, which is difficult to achieve, is the uniform dispersion of fillers within a polymer matrix to form an interconnected network. Herein, we prepared novel polydimethylsiloxane (PDMS) composites loaded with three-dimensional (3D) continuous silica fibers (i.e., silica sponge). In the composites, silica fibers maintained continuous fibrous structure, achieved uniform distribution, and showed strong interfacial adhesion with PDMS, which together contributed to a dramatic improvement in mechanical properties compared with pure PDMS and PDMS loaded with glass fibers. With a loading level of only 1wt%, the tensile modulus, strength, strain-at-break, and tear strength of the composites improved by 140%, 94%, 18%, and 95%, respectively, compared to PDMS. In addition, these composites retained good transparency. More importantly, this silica fiber filler system is widely applicable and can be used to prepare various high performance polymer composites.

Preparation of MCC/MC Silica Sponge and Its Oil/Water Separation Apparatus Application

A novel superoleophilic sponge, which has been prepared by a simple sol–gel process using microcrystalline cellulose (MCC) and methyl cellulose (MC), and its oil/water separation apparatus application are presented here. The samples were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectra (FTIR), and so on. The results indicated that MCC/MC silica sponge (MCC-CH3) had been successfully introduced C═O and methyl groups and exhibits better mechanical properties, absorption capacity, and high oil selectivity. Besides, a novel oil–water separation apparatus was designed to make MCC-CH3 a further practical application. Based on this simple but flexible and intelligent design, oil collection, sorption materials regeneration, and free navigation can be simultaneously achieved in the remediation of oil spills. The results showed the discharge flow of n-hexane was about 11700 g·h–1·g–1, and the oil ratio of the discharge mixture reached 99% under a conti...

Phospholipid–silica mesophases formed in hydroalcoholic solution as precursors of mesoporous silica

The fusion of lipid bilayers in sponge silica–lecithin composites is favoured by natural cosurfactants-induced local opposite curvatures.

Eshelby Twist as a Possible Source of Lattice Rotation in a Perfectly Ordered Protein/Silica Structure Grown by a Simple Organism.

The formation mechanism of a perfectly ordered protein/silica structure in the axial filament of the anchor spicule of the silica sponge Monorhaphis chuni is suggested. Experimental evidence shows that the growth of this architecture is realized by a thermodynamically driven dislocation-mediated spiral growth mechanism, resulting in a specific rotation of the mesoscopic crystal lattice (Eshelby twist).

Electron microscope analyses of the bio-silica basal spicule from the Monorhaphis chuni sponge.

We report on a structural analysis of several basal spicules of the deep-sea silica sponge Monorhaphis chuni by electron microscope techniques supported by a precise focused ion beam (FIB) target preparation. To get a deeper understanding of the spicules length growth, we concentrated our investigation onto the apical segments of two selected spicules with apparently different growth states and studied in detail permanent and temporary growth structures in the central compact silica axial cylinder (AC) as well as the structure of the organic axial filament (AF) in its center. The new findings concern the following morphology features: (i) at the tip we could identify thin silica layers, which overgrow as a tongue-like feature the front face of the AC and completely fuse during the subsequent growth state. This basically differs from the radial growth of the surrounding lamellar zone of the spicules made of alternating silica lamellae and organic interlayers. (ii) A newly detected disturbed cylindrical zone in the central region of the AC (diameter about 30 μm) contains vertical and horizontal cavities, channels and agglomerates, which can be interpreted as permanent leftover of a formerly open axial channel, later filled by silica. (iii) The AF consists of a three-dimensional crystal-like arrangement of organic molecules and amorphous silica surrounding these molecules. Similar to an inorganic crystal, this encased protein crystal is typified by crystallographic directions, lattice planes and surface steps. The 〈001〉 growth direction is especially favored, thereby scaffolding the axial cylinders growth and consequently the spicules' morphology.

Marine Sponges, Other Animal Food, and Nonfood Items Found in Digestive Tracts of the Herbivorous Marine Turtle Chelonia mydas in Hawai'i

Although the usual diet of Chelonia mydas comes from algae and sea grasses (plant material), animal material has been found in samples taken over the past 35 yr. The small black-brown protein sponge Chondrosia chucalla resembles the alga Codium arabicum in size, color, and texture, and both grow next to each other on the reefs. We hypothesize that turtles are actively seeking and eating these sponges and not mistaking them for C. arabicum. Both protein and silica sponges occur in the diet of Chelonia, but only 6.8% of the time are eaten in addition to their usual plant diet. Thirty different kinds of other animals were found in the samples, including Cnidaria, Mollusca, Crustacea, Insecta, Echinodermata, squid, fish, tumor flesh, and other animals but in low frequency (5%). Most of the miscellaneous nonfood debris items were terrestrial leaves, plastic, paper, string, fibers, hair, and paint chips but also in low frequency (<7%). Among animal food items known to have nutritional value, the protein sponge C. chucalla could be contributing an important nutritive factor, but this needs further research.

Characterization of an Endoplasmic Reticulum-associated Silaffin Kinase from the Diatom Thalassiosira pseudonana

The formation of SiO(2)-based cell walls by diatoms (a large group of unicellular microalgae) is a well established model system for the study of molecular mechanisms of biological mineral morphogenesis (biomineralization). Diatom biomineralization involves highly phosphorylated proteins (silaffins and silacidins), analogous to other biomineralization systems, which also depend on diverse sets of phosphoproteins (e.g. mammalian teeth and bone, mollusk shells, and sponge silica). The phosphate moieties on biomineralization proteins play an essential role in mineral formation, yet the kinases catalyzing the phosphorylation of these proteins have remained poorly characterized. Recent functional genomics studies on the diatom Thalassiosira pseudonana have revealed >100 proteins potentially involved in diatom silica formation. Here we have characterized the biochemical properties and biological function of one of these proteins, tpSTK1. Multiple tpSTK1-like proteins are encoded in diatom genomes, all of which exhibit low but significant sequence similarity to kinases from other organisms. We show that tpSTK1 has serine/threonine kinase activity capable of phosphorylating silaffins but not silacidins. Cell biological and biochemical analysis demonstrated that tpSTK1 is an abundant component of the lumen of the endoplasmic reticulum. The present study provides the first molecular structure of a kinase that appears to catalyze phosphorylation of biomineral forming proteins in vivo.

Structure and Mechanical Properties of Silica Sponge Spicule

The structure and mechanical properties of silica sponge spicule found in China Bo-hai were studied.The results show that this spicule has the complex hiberarchy:the first tier is nano silica particles;the second tier is the sub-rounds within one silica round;the third tier is silica rounds composed of several parallel sub-rounds;the fourth tier is homocentric round structure with alternant deposition of silica and organic matrix.The flexural strength of this spicule is 394.34GPa,the flexural modulus increases with the growth direction of rounds.The cross-sectional hardness is 2.933GPa,and the cross-sectional Yang's modulus can reach 33.308GPa.

Biomolecular Self-assembly and its Relevance in Silica Biomineralization

Biomineralization, which means the formation of inorganic materials by biological processes, currently finds increasing research interest. It involves the synthesis of calcium-based minerals such as bones and teeth in vertebrates, and of shells. Silica biomineralization occurs, for example, in diatoms and silica sponges. Usually, biominerals are made up of amorphous compounds or small microcrystalline domains embedded into an amorphous matrix. Nevertheless, they exhibit very regular shapes and, as in the case of diatoms, intricate nanopatterns of amazing beauty. It is, therefore, commonly assumed that biominerals are formed under the structure-directing influence of templates. However, single molecules are by far too small to direct the formation of the observed shapes and patterns. Instead, supramolecular aggregates are shown to be involved in the formation of templating superstructures relevant in biomineralization. Specific biomolecules were identified in both diatoms and silica sponges, which elegantly combine two indispensable functions: on the one hand, the molecules are capable of inducing silica precipitation from precursor compounds. On the other hand, these molecules are capable of self-assembling into larger, structure-directing template aggregates. Such molecules are the silaffins in the case of diatoms and the silicateins in sponges. Long-chain polyamines of similar composition have meanwhile been discovered in both organisms. The present review is especially devoted to the discussion of the self-assembly behavior of these molecules. Physico-chemical studies on a model compound, poly(allylamine), are discussed in detail in order to elucidate the nature of the interactions responsible for self-assembly of long-chain polyamines and the parameters controlling this process. Numerous biomimetic silica synthesis experiments are discussed and evaluated with respect to the observations made on the aforementioned "natural" biomolecules.

Fabrication of helical hybrid silica bundles

A series of C2-symmetric bridged silsesquioxanes derived from L- and D-valine have been designed and synthesized. They were capable of forming physical gels in organic solvents such as ethanol, THF, and 1,4-dioxane. These silsesquioxanes formed helical bundles in 1,4-dioxane. With respect to the helical sense, a clear odd–even effect was found in the carbon number of the central alkylene segment. The silsesquioxanes with odd number alkylene segments derived from L-valine tended to self-assemble into right-handed helical bundles. On the contrary, those with even number alkylene segments tended to form left-handed helical bundles. Moreover, enantiomers derived from D-valine showed the opposite helical sense. The p : d ratio played an important role in the determination of helical sense. After sol–gel polycondensation under catalysts such as HCl, NaOH, and TBAF, helical hybrid silica bundles were identified in FESEM images. The helical sense of the bundles was sensitive to the catalysts and reaction conditions. Hybrid silica sponges showing both superoleophilic and superhydrophobic properties were obtained under a HCl diffusion procedure.