A series of novel cis poly(phenylacetylene)s (PPAs) substituted at the meta-position(s) by both achiral alkoxycarbonyl and chiral alkylamide groups, i.e., rP-I, sP-I to sP-V, or by just a chiral alkylamide group, i.e., rP-VI, were synthesized under catalysis of [Rh(nbd)Cl]2. The dependence of the elongation, screw sense, and stimuli response of helical polyene backbone on the structure and number of substituent was systematically investigated in both solution and solid states. Stretched cis–transoid helices with opposite signs coexisted in the DMF solution of either sP-I or rP-I, but a single handed, contracted cis–cisoid one formed in the mixture of DMF/THF (10/90, v/v). Increasing the substituent size made the polymers sP-III, sP-IV, and sP-V to take only single handed stretched cis–transoid helical conformations regardless of the solvent polarity. The N-methylation of the amide group in sP-II caused a similar effect. With the removal of achiral methoxycarbonyl substituent, rP-VI took just a stretched cis–transoid helical conformation in polar DMF, whereas it existed as a mixture in equilibrium of stretched cis–transoid and contracted cis–cisoid helices with identical screw sense in less polar solvents such as dioxane, THF, and chloroform. The twisting directions of substituent array and polyene backbone were found to be coincident in a dynamic, contracted helix, but the opposite in a less dynamic, stretched helix. These results suggested that the 3,5-disubstitution, strong intramolecular hydrogen bonding, and small substituent favored the formation of contracted cis–cisoid helices for PPAs.

The unsymmetrical salphen ligand (3,5-tBu-1-OH-C6H2)CH═N-C6H4-N═CH(3-Ph-1-OH-C6H3) (tBu-PhLH2) was designed and synthesized to support aluminum complexes. Its symmetric analogues, (3,5-tBu-1-OH-C6H2)CH═N-C6H4-N═CH(3,5-tBu-1-OH-C6H2) (tBuLH2) and (3-Ph-1-OH-C6H3)CH═N-C6H4-N═CH(3-Ph-1-OH-C6H3) (PhLH2), were also explored and compared. The methane elimination reactions between ligands and AlMe3 resulted in formation of tBu-PhLAlMe (1), tBuLAlMe (2), and PhLAlMe (3) in high yields, which were characterized by elemental analysis, 1H and 13C NMR. The coordination geometries of unsymmetrical and symmetric ligands in 1 and 2 were studied by X-ray diffractions, which revealed a five-coordinated distorted square-pyramidal geometry around Al centers. The aluminum methyl compounds 1–3 reacted with BnOH at 70 °C to give tBu-PhLAlOBn (4), tBuLAlOBn (5), and PhLAlOBn (6), respectively, which existed as monometallic species in solution as indicated by NMR studies. However, the aluminum isopropoxide prepared by the reaction of tBu-PhLH2 with 1 equiv of Al(OiPr)3 contained three species, one monometallic tBu-PhLAlOiPr (7) and two bridged dimers μ-O2-(cis-tBu-PhLAlOiPr)2 (8) and μ-O2-(trans-tBu-PhLAlOiPr)2 (9). The catalytic performances of unsymmetrical 4 for the ring-opening polymerization of racemic lactide (rac-LA) were preliminarily studied and compared to those of symmetric 5 and 6.

Smart hydrogels have received increasing attention for many applications. Here, we synthesized a class of cationic peptide amphiphiles that can self-assemble into hydrogels by ring-opening polymerization (ROP) and post-modification strategy. The incorporation of cationic lysine residues suppresses the formation of fibril-like structure and further the gelation ability of the samples. Sodium alginate (SA) is used to enhance the rheology performance of the hydrogels. The hydrogels exhibit pH-dependent self-assembly and the gelation behavior that enables them to be ideal smart hydrogel systems for biomedical applications. Furthermore, the as-prepared hybrid peptide hydrogels show antibacterial activity.

Surface-grafted poly-γ-benzyl-glutamate brushes with different secondary structures were prepared and used to study the influence of main-chain chirality on cell adhesion behaviors. Cells could adhere and proliferate better on L-type poly-γ-benzyl-glutamate grafted surfaces than on the enantiomers.

Polymer/inorganic nanocomposite (NC) hydrogels usually display super mechanical properties, due to their 3D crosslinked network of delaminated inorganic nanoparticles and polymers as well as strong interfacial interactions. Multiple functions including photoluminescence are strongly desired for their applications. In this study, we report layered rare-earth hydroxide (LRH)/polyacrylamide NC hydrogels with highly colour-tunable photoluminescence functions by a cascaded energy transfer effect. These NC hydrogels based on LRHs containing Gd3+, Tb3+ or Eu3+ ions are fabricated via a convenient and green in situ polymerization procedure. Diverse photoluminescent colours are clearly observed, ranging from green, yellow-green, yellow, reddish-orange, yellowish pink, pink to bluish violet. Furthermore, these NC hydrogels exhibit long luminescence lifetimes and high quantum efficiencies. More interestingly, such fascinating photoluminescence features are highly tunable by varying the constituent or concentration of LRHs, and the excitation wavelength. Finally, a cascaded energy transfer pathway is proposed to elucidate the molecular mechanism of the tunable multiple-colour photoluminescence functions, i.e. the LRH host → sensitizer sodium salicylate (SA) → Tb3+, and finally Tb3+ → Eu3+.

In this study, we propose a novel strategy for the preparation of furandicarboxylic acid (FDCA) based polyesters through the melt polycondensation of asymmetric monomers with terminal methyl ester and hydroxyl groups. A series of bio-based polyesters were prepared from dimethyl 2,5-furandicarboxylate and diols containing long alkyl chains. In this strategy, volatile methanol rather than diols with high boiling points was removed as a by-product. The effects of the catalyst concentration, reaction temperature and reaction time on the molecular weight and PDI were investigated. Polyesters with high molecular weights and without coloration were obtained at a lower polycondensation temperature and in less time in comparison with previous methods. The thermal and mechanical properties of the as-prepared polyesters were investigated by DSC, TGA, DMA and tensile testing. The results revealed that the thermal and mechanical properties of the polyesters including Tm, Tc, Tg, Young's modulus, tensile strength and elongation at break, not only depended on the number of methylene groups but also were related to the odd–even effect.

The impact of hydrogen bond formation on the supramolecular assembly of two perylene imide derivatives (PMAMI and PDINH) was systematically investigated in solution and at the liquid–solid interface. PDINH has intrinsic hydrogen bond sites, but this is not the case for PMAMI. The solution assembly was explored by morphological methods (SEM, AFM, TEM and cryo-TEM) and spectral characterization (UV-vis, FL, XRD, and FTIR spectra). The surface assembly at the liquid–solid interface was detected by scanning tunneling microscopy (STM). It was found that in a mixed solution (THF/MeOH, 10 v%/90 v%), PMAMI formed nanofibers together with large sheet structures and PDINH assembled into uniform nanosheets, suggesting different molecular packing routes. The assembled structures could be adjusted by varying the solvent polarity for both molecules. At the liquid–solid interface, clearly distinguished surface nanostructures from PMAMI and PDINH were easily observed. Based on all spectral and morphological characterizations, it was suggested that in solution the assembly of PMAMI was mainly derived by π–π stacking interactions; on the other hand, the synergetic interaction of hydrogen bonds and π–π stacking was the reason for the hierarchical assembly of PDINH. Hydrogen bonds could be formed both for PMAMI and PDINH and stabilized nanostructures at the liquid–solid interface. This investigation could be useful in designing perylene imide-based building blocks for fabricating supramolecular assemblies with predetermined nanostructures and properties.

A dimethacryl amide functionalized perylene bisimide monomer was synthesized. Such a polymerizable monomer can self-assemble into a one dimensional rod-like structure with a mean diameter of ca. 100 nm and a length of several micrometers. The preformed supramolecular assemblies were characterized by UV-Vis spectroscopy, TEM, FE-SEM, X-ray diffraction and differential scanning calorimetry. In situ free radical polymerization was then performed in the organized state to maintain the assembly structures, and the nanorods retained their original shapes after polymerization. A significant result is that the long-range π-electron delocalization enables enhancement of the electrical conductivity of these polymeric nanorods, which facilitates the construction of electronic devices.

AbstractA new superbase, the cyclic trimeric phosphazene base (CTPB), was prepared with high yield and purity. In the presence of alcohol, the CTPB serves as a highly efficient organocatalyst for ring-opening polymerization of the “non-polymerizable” γ-butyrolactone to offer well-defined poly(γ-butyrolactone) with high conversions (up to 98 %) at −60 °C. The produced polymers have high molecular weights (up to 22.9 kg mol−1) and low polydispersity distributions (1.27–1.50). NMR analysis of initiation process and the structural analysis of resulting polymers by MALDI-TOF suggest a mechanism involving an activating initiator which leads only to linear polymers with BnO/H chain ends.

AbstractA new superbase, the cyclic trimeric phosphazene base (CTPB), was prepared with high yield and purity. In the presence of alcohol, the CTPB serves as a highly efficient organocatalyst for ring-opening polymerization of the “non-polymerizable” γ-butyrolactone to offer well-defined poly(γ-butyrolactone) with high conversions (up to 98 %) at −60 °C. The produced polymers have high molecular weights (up to 22.9 kg mol−1) and low polydispersity distributions (1.27–1.50). NMR analysis of initiation process and the structural analysis of resulting polymers by MALDI-TOF suggest a mechanism involving an activating initiator which leads only to linear polymers with BnO/H chain ends.

Poly(ε-caprolactones) (PCLs) with low catalyst loading and high molecular weights are highly desired considering their practical applications. In this work, cyclic trimeric phosphazene base (CTPB) has been developed and applied as an efficient organocatalyst in the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). It is found that CTPB could directly catalyze the ROP of ε-CL but with a relatively low activity. In contrast, CTPB with alcohol as the initiator exhibits extremely high efficiency toward the ROP of ε-CL and rapidly converts hundreds even thousands equiv. monomers into PCLs with high conversions and controlled and high molecular weights. Both mono- and multi-hydroxy-alcohols are efficient as initiators, and thus PCLs with different topologies can be easily prepared. Moreover, with excess of alcohol, the title catalytic system represents a rare example of immortal polymerization by an organocatalyst for ε-CL.

Smart hydrogels have received increasing attention for their great potential for the applications in many fields. Herein, we report a facile approach to prepare a class of dual-responsive hydrogels assembled from synthetic statistical/block thermal-responsive copoly(L-glutamate)s copolymerized with poly(ethylene glycol), which were prepared by ring-opening polymerization (ROP) and post-modification strategy. The incorporation of oligo(ethylene glycol) (OEG) and glutamic acid residues offers the gels with thermal- and pH-responsive properties simultaneously. We have systematically studied the influence of both temperature and pH on the gelation behaviors of these copolymers. It is found that the increase of glutamic acid content and solution pH values can significantly suppress the gelation ability of the samples. Circular dichroism (CD) results show that the α-helix conformation appears to be the dominant secondary conformation. More interestingly, the gelation property of the block copolymer with statistical thermal-responsive copoly(L-glutamate)s shows greater dependence on pH as compared to that with block segments due to the distinct morphology of the self-assemblies. The obtained hydrogels exhibit pH-dependent and thermal-responsive gelation behaviors, which enable them as an ideal smart hydrogel system for biomedical applications.

•A series of copoly(L-glutamate)s with both the oligo(ethylene glycol) (OEG) moiety and glutamic acid residues are synthesized.•An entirely reversible pH-dependent thermal-responsive behavior with tunable phase transition temperatures is demonstrated.•The reduced CD signal upon heating above the clouding point (CP) is entirely due to the aggregation of the polymer chains.•The solution behavior of block copolypeptide is less dependent on pH.Smart protein-mimetic materials have received increasing interest for many applications. Here, we reported a facile and efficient approach to prepare a class of dual-responsive copoly(l-glutamate)s by ring-opening polymerization (ROP) and post-modification strategy. Both the oligo(ethylene glycol) (OEG) and glutamic acid residues were incorporated to offer thermal- and pH-responsive property simultaneously. We present a systematic study of the influence of both temperature and pH on the solution properties of the copolypeptides. The copolypeptides show entirely reversible pH-dependent thermal-responsive behaviors with tunable phase transition temperatures. It is demonstrated that the sequence of the polymer units can also influence the solution behavior. The α-helix conformation appears to be the dominant secondary conformation, which shows the pH dependence, but generally irrespective of the temperature. We further verify that the reduced circular dichroism (CD) signal upon heating above the clouding point (CP) is entirely due to the aggregation of the polymer chains. All these features make the obtained polypeptides potential candidates for next generation of smart protein-mimetic materials.Download high-res image (241KB)Download full-size image

Polyethylene glycol modified diperylene bisimide (PEG-diPBI) was synthesized and applied to disperse single-walled carbon nanotubes (SWCNTs) in water. The aqueous dispersion efficiency of PEG-diPBI on SWCNTs is investigated by UV-vis, Raman spectroscopy, and transmission electron microscopy. It is found that the enhanced dispersing capability of PEG-diPBI can be attributed to the diperylene aromatic core, which can strongly interact with SWCNT via synergistic π–π and hydrophobic interactions. The dispersing solution properties are closely related to the hydrophilic part of PEG-diPBI. Moreover, the well-dispersed SWCNTs show excellent antibacterial activities.

Co-assembly of n-type semiconductors NDI and PDI with p-type pyrene derivatives resulted in the formation of stable organogels, which was induced by the strong charge transfer (CT) interactions between acceptors and donors in chloroform. The dimension size of the aromatic core from the acceptors was found to have a significant impact on the organogels. The width of the fibers from CT gels with NDI is about twice that from gels with PDI. It was found that the acceptor NDI preferred an alternate stacking with donors, intercalated with each other via CT interactions. In contrast, the acceptor PDI preferred to stack among themselves within the assemblies and this arose from the stronger π–π interactions because they had larger aromatic cores than the acceptor NDI. The dimension size of the aromatic core has been proved to have a significant impact on the organogels. The substituent impact of the donors was also studied.

The impact of halogen⋯halogen interactions on the 2D crystallization of n-semiconductors was investigated. The 2D nanostructures and chirality could be altered by the introduction of bromine atoms for both single component and binary surface assembly supported by STM and simulation results.

Aerogels with low density and high porosity exhibit outstanding performances as thermal or acoustic insulators. However, most aerogels are mechanically brittle and need further chemical or physical surface treatments to obtain elasticity and superhydrophobicity. Structurally new types of polysilsesquioxane (PSQ) aerogels containing thiourethane as their bridging groups are now reported. These novel PSQ aerogels were prepared from thiourethane bridged silsesquioxane through a simple sol–gel process and vacuum-drying method. The PSQ aerogels exhibit inherent superhydrophobicity, excellent mechanical toughness and good thermal insulation properties. Moreover, the morphology and mechanical performance of these aerogels can be tailored by changing the rigidity of the bridging group.

Infection and thrombosis associated with medical implants cause significant morbidity and mortality worldwide. As we know, current technologies to prevent infection and thrombosis may cause severe side effects. To overcome these complications without using antimicrobial and anticoagulant drugs, we attempt to prepare a liquid-infused poly(styrene-b-isobutylene-b-styrene) (SIBS) microfiber coating, which can be directly coated onto medical devices. Notably, the SIBS microfiber was fabricated through solution blow spinning. Compared to electrospinning, the solution blow spinning method is faster and less expensive, and it is easy to spray fibers onto different targets. The lubricating liquids then wick into and strongly adhere the microfiber coating. These slippery coatings can effectively suppress blood cell adhesion, reduce hemolysis, and inhibit blood coagulation in vitro. In addition, Pseudomonas aeruginosa (P. aeruginosa) on the lubricant infused coatings slides readily, and no visible residue is left after tilting. We furthermore confirm that the lubricants have no effects on bacterial growth. The slippery coatings are also not cytotoxic to L929 cells. This liquid-infused SIBS microfiber coating could reduce the infection and thrombosis of medical devices, thus benefiting human health.Keywords: antibacterial; hemocompatibility; microfiber; slippery coating; solution blow spinning; thermoplastic elastomer

A series of poly(L-glutamate) bearing Y-shaped oligo(ethylene glycol)x (OEGx) side-chains (PPLG-g-EGx, x = 2, 3 and 4) were synthesized via a combination of ring opening polymerization (ROP) of γ-propargyl-L-glutamate N-carboxyanhydride (PLG-NCA) with thiol–yne photoaddition. The solubility of the polypeptides in water was firstly investigated. PPLG-g-EG3 and PPLG-g-EG4 were soluble in water and displayed fully reversible thermal-responsive behaviors. Additionally, the polypeptides showed redox-responsive properties along with the conformation associated water solubility due to the presence of thioether groups in the side-chains. In particular, the clouding points (CPs) of the polypeptides are highly tunable depending on the degree of polymerization (DP), the side-chain length, the polymer/salt concentration, and the degree of oxidation/reduction. The key feature of our design is the simultaneous incorporation of thermal-responsive OEG units and redox-responsive thioether linkages by one-step thiol–yne photoaddition, which allows for precisely tuning the phase transition temperature by both stimuli. This synthetic approach offers a facile and efficient way to prepare polypeptide-based biomaterials with highly tunable properties.

•Polymethacrylamide homopolymers based on tertiary amine-modified l-alanine are prepared.•The incorporated natural amino acid moiety endow polymers with optical activity.•Monomer structure is critical for polymer to exhibit desired responsive property.•Polymers display LCST in basic pH range and effects of various factors are studied.•Copolymerization is not necessary to obtain multi-responsive polymers.Four poly(N-methacryloyl-l-alanine) homopolymers containing different tertiary amine moieties, dimethylaminoethyl, dimethylaminopropyl, diethylaminoethyl, and diethylaminopropyl, were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization in an effort to use natural amino acids as building blocks to design stimuli-responsive polymers that display pH-tunable lower critical solution temperature (LCST) transitions in the basic pH range. Monomer structure was found to be critical for the corresponding polymer to exhibit desired stimuli-responsive properties in water. While all four polymethacrylamides showed thermosensitive property in water, only poly(N-methacryloyl-l-alanine 2-(diethylamino)ethylamide) (PMAEE) exhibited LCST behavior in a wide pH range, from 9.0 to 13.0. Other polymers' thermoresponsive properties were found either at very high pH values (e.g., ≥13.0) or in a rather narrow pH range. The effects of pH, polymer molecular weight, polymer concentration, presence of NaCl, and end groups on cloud point of PMAEE in water were investigated; the cloud point decreased with the increase of solution pH and polymer concentration, the addition of NaCl, and the introduction of a more hydrophobic end group but varied little with polymer molecular weight. The incorporation of tertiary amine moieties endowed the polymers with a CO2-responsive property; we demonstrated that the thermosensitive property of PMAEE can be reversibly tuned by bubbling its solution alternately with CO2 and N2 gases.

A series of poly(L-glutamate)s grafted with oligo(ethylene glycol) (OEG) side-chains through the thioether linkages (PALGn-g-EGx, x = 2, 3 and 4) were prepared by ring-opening polymerization (ROP) of γ-allyl-L-glutamate N-carboxyanhydride (ALG-NCA) and thiol-ene photoaddition. The chemical structures and physical properties were characterized by 1H-NMR, Fourier transform infrared (FTIR), circular dichroism (CD), etc. The PALGn-g-EGx samples with x = 3 and 4 displayed lower critical solution temperature (LCST) in water due to the presence of OEG units. The clouding point (CP) of polypeptides can be finely tuned by changing the side chain structures, molecular weights and sample concentrations. In addition, the thioether linkages in the side chains offer additional redox-responsive properties. The influence of both OEG units and thioether linkages on the LCST behavior was systematically investigated. This work provides an efficient way to prepare multi-stimuli responsive materials with highly tunable properties.

Two novel thermo-responsive polymer brushes were prepared from L-alanine derivatives using the surface-initiated atom transfer radical polymerization (SI-ATRP) technique. The temperature-induced cell capture and release on both polymer brush modified substrates were further explored.

A convenient green preparation method has been developed to achieve layered double hydroxide (LDH)/polymer nanocomposite (NC) hydrogels. In contrast to previous publications using toxic organic solvent of formamide or methanol in LDH exfoliation or anion exchange, the interlayer anion exchange and exfoliation of LDH are completed in one step with the help of an amino acid (L-serine). The LDH/polyacrylamide (PAM) NC hydrogels are achieved by a convenient exfoliation–adsorption in situ polymerization method. The exfoliation of LDH is characterized by dynamic light scattering and transmission electron microscopy. Interestingly, the developed NC hydrogels reveal ultrahigh deformability and extraordinary stretchability, confirmed by qualitative images and qualitative tensile and compression tests. The molecular mechanism for the ultrahigh deformability and extraordinary stretchability is discussed by crosslinking density, inter-crosslinking molecular weight and swelling tests. We believe that the findings reported herein will deepen our understanding towards the chemistry of network soft materials including gels, and further widen the applications of polymer hydrogels in mechanical devices such as artificial muscles, biomedical devices and drug delivery systems.

Porous aerogels are an inspiring absorbent for oil–water separation and water purification. In particular, hydrophobic silica aerogels from abundant and cheap sources offer both economical and environmental benefits. Conventional silica aerogels from alkoxy siloxane precursors involve time-consuming and laboursome multistep processes. Herein, we demonstrate the formation of flexible superhydrophobic polysiloxane aerogels through a facile hydrosilylation from functionalized polydimethylsiloxane in supercritical carbon dioxide. This robust aerogel exhibits a high oil absorption capacity, superior recyclability and extraordinary mechanical properties even under harsh heating and cooling cycles. These characters favor this polysiloxane aerogel as being more competitive than common alkoxy silica ones for oily water treatment, oil spill clean-up and oil recovery.

A poly(ethylene glycol)-b-poly(L-lysine)-b-poly(styrene) (PEG-PLL-PS) triblock copolymer, which contains a cationic PLL block as the middle block, is synthesized via a combination of ring-opening polymerization (ROP) and atom-transfer radical polymerization (ATRP). The PEG-PLL-PS (ELS) triblock is employed as a macromolecular surfactant to form a stable oil-in-water (O/W) emulsion, which is subsequently used as the template to prepare Janus silica hollow spheres (JHS) via a one-pot biosilicification reaction. For the emulsion template, the middle PLL block assembles at the O/W interface and directs the biomimetic silica synthesis in the presence of phosphate buffer and silicic acid precursors. This biosilicification process takes place only in the intermediate layer between water and the organic interior phase, leading to the formation of silica JHSs with hydrophobic PS chains tethered to the inner surface and PEG attached to the outer surface. The three-layer JHSs, namely, PEG/silica-polylysine/PS composites, were verified by electron microscopy. Upon further breaking these JHSs into species, polymer-grafted Janus silica nanoplates (JPLs) can be obtained. Our studies provide an efficient one-step method for preparing hybrid silica Janus structures within minutes.

Polypeptide brushes are attractive platforms to generate functional and responsive interfaces that are of potential interest due to their possible biodegradability, biocompatibility and tunable secondary structures. Surface-initiated ringopening polymerization (SI-ROP) of α-amino acid N-carboxyanhydrides represents a powerful and versatile strategy to generate polypeptide brushes. This review is an attempt to capture the state-of-the-art in this field and highlights the latest developments in several selected areas. In addition to presenting an overview of the synthetic methods that have been used to generate polypeptide brushes via SI-ROP, this article will discuss the preparation of patterned polypeptide brushes, the conformational properties of surface-tethered polypeptides, ways to control chain orientation at surfaces as well as properties and applications of these thin polymer films.

Polymer/inorganic nanocomposite (NC) hydrogels usually display super mechanical properties, due to their 3D crosslinked network of delaminated inorganic nanoparticles and polymers as well as strong interfacial interactions. Multiple functions including photoluminescence are strongly desired for their applications. In this study, we report layered rare-earth hydroxide (LRH)/polyacrylamide NC hydrogels with highly colour-tunable photoluminescence functions by a cascaded energy transfer effect. These NC hydrogels based on LRHs containing Gd3+, Tb3+ or Eu3+ ions are fabricated via a convenient and green in situ polymerization procedure. Diverse photoluminescent colours are clearly observed, ranging from green, yellow-green, yellow, reddish-orange, yellowish pink, pink to bluish violet. Furthermore, these NC hydrogels exhibit long luminescence lifetimes and high quantum efficiencies. More interestingly, such fascinating photoluminescence features are highly tunable by varying the constituent or concentration of LRHs, and the excitation wavelength. Finally, a cascaded energy transfer pathway is proposed to elucidate the molecular mechanism of the tunable multiple-colour photoluminescence functions, i.e. the LRH host → sensitizer sodium salicylate (SA) → Tb3+, and finally Tb3+ → Eu3+.

Surface-grafted poly-γ-benzyl-glutamate brushes with different secondary structures were prepared and used to study the influence of main-chain chirality on cell adhesion behaviors. Cells could adhere and proliferate better on L-type poly-γ-benzyl-glutamate grafted surfaces than on the enantiomers.

Aerogels with low density and high porosity exhibit outstanding performances as thermal or acoustic insulators. However, most aerogels are mechanically brittle and need further chemical or physical surface treatments to obtain elasticity and superhydrophobicity. Structurally new types of polysilsesquioxane (PSQ) aerogels containing thiourethane as their bridging groups are now reported. These novel PSQ aerogels were prepared from thiourethane bridged silsesquioxane through a simple sol–gel process and vacuum-drying method. The PSQ aerogels exhibit inherent superhydrophobicity, excellent mechanical toughness and good thermal insulation properties. Moreover, the morphology and mechanical performance of these aerogels can be tailored by changing the rigidity of the bridging group.